Hello, here Jorge. On this post I will explain how to enable MQS1 on i.MX8ULP. As background about how to setup the environment to build the image using Yocto, please take a look on our i.MX Yocto Project User's Guide: Requirements: i.MX 8ULP EVK. Serial console emulator (Tera Term, Putty, etc.). USB Type-C cable. Micro USB cable. Headphones/speakers. Linux PC. Build done in Linux 6.6.23_2.0.0. i.MX8ULP audio subsystem. i.MX 8ULP extends audio capabilities on i.MX 7ULP by adding dedicated DSP cores for voice trigger and audio processing, enabling lower latency and power efficiency to support variety of audio applications. Some of hardware blocks implemented on 8ULP to support audio use cases are the next: Cadence Fusion F1 DSP processor. Cadence HiFi4 DSP processor. PowerQuad hardware accelerator with fixed and floating + FFT. Digital Microphone interface with support of up-to 8 PDM channels. Up-to 8 independent SAI instances. Up-to 2 Medium Quality Sound (MQS). Sony/Philips Digital interface (SPDIF). As is described before, MQS0 and MQS1 are part of real time domain and application domain respectively. I’m going to focus this post on how to enable MQS1 on application domain. Medium Quality Sound (MQS)  This module is basically generates a PWM from PCM audio data. For the major part of typical audio applications will require an external CODEC to deliver the audio quality but, sometimes where the application does not demand this quality, MQS can provide a medium quality audio via GPIO pin that can directly drive the audio output to a speaker or headphone via inexpensive external amplifier/buffer instead of CODEC. The design of the MQS can be described as follows: Input the PCM audio data (from SAI) into a 16-bit register. Up-sample data to match PWM switching frequency. Perform a simple 2nd order Sigma-Delta smooth on the current data versus previous data. Convert the PCM register into a 6-bit PWM width register and output through a GPIO pin.   How to enable it? By default, our BSP does not enable clock for MQS1. This clock is controlled on CGC1 (AD), specifically on MQS1CLK (Multiplexer to select the audio clock connected to the MQS clock input). So, it is needed to modify imx8ulp-clock.h and clk-imx8ulp.c. Please take a look on patch attached at the end of this post to see the modification in drivers easily. These drivers have the definition/configuration for MQS1_SEL in CGC1 and needs to be added as follows: MQS1_SEL definition needs to bed added in imx8ulp-clock.h: #define IMX8ULP_CLK_MQS1_SEL 56 #define IMX8ULP_CLK_CGC1_END 57 MQS1_SEL configuration needs to be added in imx8ulp_clk_cgc1_init of clk-imx8ulp.c: clks[IMX8ULP_CLK_MQS1_SEL] = imx_clk_hw_mux2("mqs1_sel", base + 0x90c, 0, 2, sai45_sels, ARRAY_SIZE(sai45_sels)); Also, it is necessary to configure MQS1 on device tree of i.MX8ULP. Add this in soc: soc@0 of imx8ulp.dtsi: mqs1: mqs@0x29290064 { reg = <0x29290064 0x4>; compatible = "fsl,imx8qm-mqs"; assigned-clocks = <&cgc1 IMX8ULP_CLK_MQS1_SEL>; assigned-clock-parents = <&cgc1 IMX8ULP_CLK_SPLL3_PFD1_DIV1>; clocks = <&cgc1 IMX8ULP_CLK_MQS1_SEL>, <&cgc1 IMX8ULP_CLK_MQS1_SEL>; clock-names = "core", "mclk"; status = "disabled"; }; And create a new device tree, in this case is going to be named imx8ulp-evk-mqs.dts and is as follows: #include "imx8ulp-evk.dts" / { sound-simple-mqs { compatible = "simple-audio-card"; simple-audio-card,name = "imx-simple-mqs"; simple-audio-card,frame-master = <&sndcpu>; simple-audio-card,bitclock-master = <&sndcpu>; simple-audio-card,dai-link@0 { format = "left_j"; sndcpu: cpu { sound-dai = <&sai4>; }; codec { sound-dai = <&mqs1>; }; }; }; }; &cgc1 { assigned-clock-rates = <24576000>; }; &iomuxc1 { pinctrl_mqs1: mqs1grp { fsl,pins = < MX8ULP_PAD_PTF7__MQS1_LEFT 0x43 >; }; }; &mqs1 { #sound-dai-cells = <0>; pinctrl-names = "default"; pinctrl-0 = <&pinctrl_mqs1>; status = "okay"; }; &sai4 { #sound-dai-cells = <0>; assigned-clocks = <&cgc1 IMX8ULP_CLK_SAI4_SEL>; assigned-clock-parents = <&cgc1 IMX8ULP_CLK_SPLL3_PFD1_DIV1>; status = "okay"; }; Let’s apply these changes on our BSP, in my case I’m going to create a new layer in Yocto to add these modifications with a patch that can be found at the end on this post, here the steps: Install essential Yocto Project host packages: $ sudo apt install gawk wget git diffstat unzip texinfo gcc build-essential chrpath socat cpio python3 python3-pip python3-pexpect xz-utils debianutils iputils-ping python3-git python3-jinja2 python3-subunit zstd liblz4-tool file locales libacl1 Install the “repo” utility: $ mkdir ~/bin $ curl https://storage.googleapis.com/git-repo-downloads/repo > ~/bin/repo $ chmod a+x ~/bin/repo $ export PATH=~/bin:$PATH Set up Git: $ git config --global user.name "Your Name" $ git config --global user.email "Your Email" $ git config –list Download the i.MX Yocto Project Community BSP recipe layers and create build folder: $ mkdir imx-yocto-bsp $ cd imx-yocto-bsp $ repo init -u https://github.com/nxp-imx/imx-manifest -b imx-linux-scarthgap -m imx-6.6.23-2.0.0.xml $ repo sync $ DISTRO=fsl-imx-wayland MACHINE=imx8ulp-lpddr4-evk source imx-setup-release.sh -b 8ulp_build Create the new layer: $ cd ~/imx-yocto-bsp/sources $ bibake-layers create-layer meta-mqs $ cd meta-mqs conf/layer.conf should be as follows: BBPATH .= ":${LAYERDIR}" BBFILES += "${LAYERDIR}/recipes-*/*/*.bb \ ${LAYERDIR}/recipes-*/*/*.bbappend" BBFILE_COLLECTIONS += "meta-mqs" BBFILE_PATTERN_meta-mqs = "^${LAYERDIR}/" BBFILE_PRIORITY_meta-mqs = "6" LAYERSERIES_COMPAT_meta-mqs = "nanbield" Let’s change the recipe: $ sudo rm -r recipes-example $ mkdir -p recipes-kernel/linux/files 0001-8ULP-MQS-Enable.patch should be copied to ~/imx-yocto-bsp/sources/meta-mqs/recipes-kernel/linux/files Add an append (on this case is called “linux-imx_%.bbappend”)to change the recipe with next content: FILESEXTRAPATHS:prepend := "${THISDIR}/files:" SRC_URI += "file:// 0001-8ULP-MQS-Enable.patch " addtask copy_dts after do_unpack before do_prepare_recipe_sysroot do_copy_dts () { if [ -n "${DTS_FILE}" ]; then if [ -f ${DTS_FILE} ]; then echo "do_copy_dts: copying ${DTS_FILE} in ${S}/arch/arm64/boot/dts/freescale" cp ${DTS_FILE} ${S}/arch/arm64/boot/dts/freescale/ fi fi } The next step is add the layer and build the image: $ cd ~/imx-yocto-bsp/8ulp_build $ bitbake-layers add-layer ~/imx-yocto-bsp/sources/meta-mqs Confirm that the layer has been added: $ bitbake-layers show-layers Build the image: $ bitbake imx-image-multimedia i.MX8ULP EVK limitations The i.MX8ULP has the next MQS1 pins available: But, in the EVK board, the mayor part of these pins are used for other functions such as: - Push button: - MIPI DSI:  - Etc… So, take the output signal of MQS1 pins of EVK board is difficult, in this article, I’m going to configure PTF7 only (MQS1_left) for practicality. If you are working with this board and you need to use these pins for MQS function you will need to manipulate the traces and take the required signals. If you are designing a custom board, planning is essential to avoid this issue. Flash the board. One the build has been finished, we will have the necessary files to flash the board and test it. If you are not too familiarized with this process I suggest you take a look on this post. First, put the board in serial download mode changing the boot configuration switches on the board:   The next step is connecting the power cable, micro-USB cable on the debug port and USB-C type cable to USB0 connector on the board. Then, turn-on the board and run the next command in terminal of build directory: uuu -b emmc_all imx-boot-imx8ulpevk-sd.bin-flash_singleboot_m33 imx-image-multimedia-imx8ulpevk.wic Now, power-off the board, change the boot mode to single boot-eMMC and power it on to test it. Test MQS1 in i.MX8ULP. To test MQS1 it is needed to change the device tree we created, we can do it with the next commands in U-boot: u-boot=> setenv fdtfile imx8ulp-evk-mqs.dtb u-boot=> saveenv u-boot=> boot Now we can test MQS1 on i.MX8ULP EVK, let's confirm that the clock is active in MQS module with the next command: $ cat /sys/kernel/debug/clk/clk_summary -n As you can see mqs1_sel is active and running at 24576000 Hz: And the card appears if we run the next command: $ aplay -l To play audio through MQS we can do it as any sound card: $ speaker-test -D sysdefault:CARD=imxsimplemqs -c 2 -f 48000 -F S16_LE -t pink -P 3 The signal should look like this in the pin output: And like this after a filter, for example the filter used in i.MX93 EVK.   With this post we have been able check the general operation of MQS, configure and compile the image with the required changes to enable MQS1 on EVK board and measure the output on the board. There is a considerable limitation on EVK board since we cannot test left and right outputs without intervene the base board, but this can be helpful as a reference to who would like to use this audio output on i.MX8ULP processor. Best regards. References. Yocto Project customization guide - NXP Community How to add a new layer and a new recipe in Yocto - NXP Community Flashing Linux BSP using UUU - NXP.  i.MX8ULP reference manual. Embedded Linux Projects Using Yocto Project Cookbook.

The user interface has limited the use of the tool GUI Guider. Getting an interaction only through a mouse or touchscreen can be enough for some use cases. However, sometimes the use case requires to go beyond its limitations. This video/appnote explores the possibility of integrating voice by creating a bridge between a speech recognition technology, such as VIT, and the interface creator GUI Guider. It uses a universal way to link all the voice recognition commands and a wakeword to any interaction created by GUI Guider. The following video shows the steps necessary to create that connection by creating the voice recognition using VIT voice commands and wakewords, create an interface of GUI Guider using a template, how to connect between them using the board i.MX 93 evk and testing it. For more information consult the following links AppNote HTML: https://docs.nxp.com/bundle/AN14270/page/topics/abstract.html?_gl=1*1glzg9k*_ga*NDczMzk4MDYuMTcxNjkyMDI0OA..*_ga_WM5LE0KMSH*MTcxNjkyMDI0OC4xLjEuMTcxNjkyMDcyMy4wLjAuMA AppNote PDF: https://www.nxp.com/docs/en/application-note/AN14270.pdf Associated File: AN14270SW  

  Some customers want to expose their i3c device on the /dev, In order to develop their i3c APP or operation the i3c device like I2C. But in our default BSP code, we do not support this feature for I3C device, This article will introduce how to make the i3c device expose to the user space. Board : i.MX 93 EVK BSP Version : lf-6.1.55-2.2.0 I3C device : LSM6DSOXTR Step 1 : Rework the i.MX93 EVK Board, Install the R1010.      Step 2 : Apply the add_i3c_device_to_dev.patch file to the linux kernel code              Command : git apply add_i3c_device_to_dev.patch Step 3 : Re-compile the kernel Image file.              Command : make imx_v8_defconfig                                  make Step 4 : Boot your board with "imx93-11x11-evk-i3c.dtb" file and see if you can see the I3C device on the /dev directory. Result : We can see the i3c device is appeared in /dev directory, The i2c-8 is an i2c device mounted to the i3c bus. The i3c is backward compatible with i2c device. It will simulate the I2C signal loading i2c device.                 PS : You can also use the i2ctool detect i2c-8 device. As shown in the following picture:   Note : If you need the patch file, Please contact me any time for free.

-- DTS for gpio wakeup   // SPDX-License-Identifier: (GPL-2.0+ OR MIT) /*  * Copyright 2022 NXP  */   #include "imx93-11x11-evk.dts"   / {         gpio-keys {                 compatible = "gpio-keys";                 pinctrl-names = "default";                 pinctrl-0 = <&pinctrl_gpio_keys>;                   power {                   label = "GPIO Key Power";                   linux,code = <KEY_POWER>;                   gpios = <&gpio2 7 GPIO_ACTIVE_LOW>;                   wakeup-source;                   debounce-interval = <20>;                   interrupt-parent = <&gpio2>;                   interrupts = <7 IRQ_TYPE_LEVEL_LOW>;                 };         }; };   &iomuxc {         pinctrl_gpio_keys: gpio_keys_grp {                 fsl,pins = <                         MX93_PAD_GPIO_IO07__GPIO2_IO07  0x31e                 >;         }; }; -- testing the switch GPIO  First check if your gpio dts configuration to make it act as a switch works or not After executing the command - 'evtest /dev/input/event1' Trigger an interrupt by connecting GPIO2 7 to GND, as soon as you do that, you will receive Event logs such as below:- This shows that your dts configuration for GPIO works.     -- Verify the interrupt         -- Go to sleep and then connect the GPIO to GND to trigger a wakeup, in the logs we see that kernel exits the suspend mode    

Hello, on this post I will explain how to record separated audio channels using an 8MIC-RPI-MX8 Board. As background about how to setup the board to record and play audio using i.MX boards, I suggest you take a look on the next post: How to configure, record and play audio using an 8MIC-RPI-MX8 Board. Requirements: I.MX 8M Mini EVK. Linux Binary Demo Files - i.MX 8MMini EVK. 8MIC-RPI-MX8 Board. Serial console emulator (Tera Term, Putty, etc.). Headphones/speakers. Waveform Audio Format WAV, known for WAVE (Waveform Audio File Format), is a subset of Microsoft’s Resource Interchange File Format (RIFF) specification for storing digital audio files. This format does not apply compression to the information and stores the audio with different sampling rates and bitrates. WAV files are larger in size compared to other formats such as MP3 which uses compression to reduce the file size while maintaining a good audio quality but, there is always some lose on quality since audio information is too random to be compressed with conventional methods, the main advantage of this format is provide an audio file without losses that is also widely used on studio. This files starts with a file header with data chunks. A WAV file consists of two sub-chunks: fmt chunk: data format. data chunk: sample data. So, is structured by a metadata that is called WAV file header and the actual audio information. The header of a WAV (RIFF) file is 44 bytes long and has the following format: How to separate the channels? To separate each audio channel from the recording we need to use the next command that will record raw data of each channel. arecord -D plughw:<audio device> -c<number of chanels> -f <format> -r <sample rate> -d <duration of the recording> --separate-channels <output file name>.wav arecord -D plughw:2,0 -c8 -f s16_le -r 48000 -d 10 --separate-channels sample.wav This command will output raw data of recorded channels as is showed below. This raw data cannot be used as a “normal” .wav file because the header information is missing. It is possible to confirm it if import raw data to a DAW and play recorded samples: So, to use this information we need to create the header for each file using WAVE library on python. Here the script that I used: import wave import os name = input("Enter the name of the audio file: ") os.system("arecord -D plughw:2,0 -c8 -f s16_le -r 48000 -d 10 --separate-channels " + name + ".wav") for i in range (0,8): with open(name + ".wav." + str(i), "rb") as in_file: data = in_file.read() with wave.open(name + "_channel_" + str(i) +".wav", "wb") as out_file: out_file.setnchannels(1) out_file.setsampwidth(2) out_file.setframerate(48000) out_file.writeframesraw(data) os.system("mkdir output_files") os.system("mv " + name + "_channel_" + "* " + "output_files") os.system("rm " + name + ".wav.*") If we run the script, will generate a directory with the eight audio channels in .wav format. Now, we will be able to play each channel individually using an audio player. References IBM, Microsoft Corporation. (1991). Multimedia Programming Interface and Data Specifications 1.0. Microsoft Corporation. (1994). New Multimedia Data Types and Data Techniques. Standford University. (2024, January 30). Retrieved from WAVE PCM sound file format: http://hummer.stanford.edu/sig/doc/classes/SoundHeader/WaveFormat/

P3T1755DP is a ±0.5°C accurate temperature-to-digital converter with a -40 °C to +125 °C range. It uses an on-chip band gap temperature sensor and an A-to-D conversion technique with overtemperature detection. The temperature register always stores a 12-bit two's complement data, giving a temperature resolution of 0.0625 °C P3T1755DP which can be configured for different operation conditions: continuous conversion, one-shot mode, or shutdown mode.   The device has very good features but, unfortunately, is not supported by Linux yet!   The P31755 works very similarly to LM75, pct2075, and other compatibles.   We can add support to P3T1755 in the LM75.c program due to the process to communicate with the device is the same as LM75 and equivalents.   https://github.com/nxp-imx/linux-imx/blob/lf-6.1.55-2.2.0/drivers/hwmon/lm75.c route: drivers/hwmon/lm75.c   The modifications that we have to do are the next:    1. We have to add the configurations to the kernel on the imx_v8_defconfig file CONFIG_SENSORS_ARM_SCMI=y CONFIG_SENSORS_ARM_SCPI=y CONFIG_SENSORS_FP9931=y +CONFIG_SENSORS_LM75=m +CONFIG_HWMON=y +CONFIG_I2C=y +CONFIG_REGMAP_I2C=y CONFIG_SENSORS_LM90=m CONFIG_SENSORS_PWM_FAN=m CONFIG_SENSORS_SL28CPLD=m    2. Add the part on the list of parts compatible with the driver LM75.c enum lm75_type { /* keep sorted in alphabetical order */ max6626, max31725, mcp980x, + p3t1755, pct2075, stds75, stlm75,   3. Add the configuration in the structure lm75_params device_params[]. .default_resolution = 9, .default_sample_time = MSEC_PER_SEC / 18, }, + [p3t1755] = { + .default_resolution = 12, + .default_sample_time = MSEC_PER_SEC / 10, + }, [pct2075] = { .default_resolution = 11, .default_sample_time = MSEC_PER_SEC / 10,   Notes: You can change the configuration of the device using .set_mask and .clear_mask, see more details on LM75.c lines 57 to 78   4. Add the ID to the list in the structure i2c_device_id lm75_ids and of_device_id __maybe_unused lm75_of_match    { "max31725", max31725, }, { "max31726", max31725, }, { "mcp980x", mcp980x, }, + { "p3t1755", p3t1755, }, { "pct2075", pct2075, }, { "stds75", stds75, }, { "stlm75", stlm75, },   + { + .compatible = "nxp,p3t1755", + .data = (void *)p3t1755 + },   5. In addition to all modifications, I modify the device tree of my iMX8MP-EVK to connect the Sensor in I2C3 of the board.  https://github.com/nxp-imx/linux-imx/blob/lf-6.1.55-2.2.0/arch/arm64/boot/dts/freescale/imx8mp-evk.dts   }; }; + + p3t1755: p3t1755@48 { + compatible = "nxp,p3t1755"; + reg = <0x48>; + }; + };   Connections: We will use the expansion connector of the iMX8MP-EVK and J9 of the P3T1755DP-ARD board.   P3T1755DP-ARD board   iMX8MP-EVK   P3T1755DP-ARD ----> iMX8MP-EVK J9              ---------->            J21 +3v3 (Pin 9) ---> +3v3 (Pin 1) GND(Pin 7) ---> GND (PIN 9) SCL (Pin 4) ---> SCL (Pin 5) SDA (Pin 3) ---> SDA (Pin 3)     Reading the Sensor We can read the sensor using the next commands:   Read Temperature: $ cat /sys/class/hwmon/hwmon1/temp1_input Reading maximum temperature: $ cat /sys/class/hwmon/hwmon1/temp1_max Reading hysteresis: $ cat /sys/class/hwmon/hwmon1/temp1_max_hyst   https://www.nxp.com/design/design-center/development-boards-and-designs/analog-toolbox/arduino-shields-solutions/p3t1755dp-arduino-shield-evaluation-board:P3T1755DP-ARD    

Sometime need standalone compile device tree. Only Linux headers and device tree directory are needed.         

This article is rather short that only mentions the script that is needed to make an iMX93EVK act as a USB mass storage device so that whenever you connect your iMX device to a windows/linux system via USB, it should get enumerated something like a usb drive.  The storage that is used in this example is mmc so the expectation is that you have inserted a mmc card in the slot. Below is the script:- #!/bin/sh   # This composite gadget include function: # - MASS STORAGE     # # Exit status is 0 for PASS, nonzero for FAIL # STATUS=0   # Check if there is udc available, if not, return fail UDC_DIR=/sys/class/udc if test "$(ls -A "$UDC_DIR")"; then echo "The available udc:" for entry in "$UDC_DIR"/* do echo "$entry" done else STATUS=1 echo "No udc available!" exit $STATUS; fi   id=1; udc_name=ci_hdrc.0 #back_file=/dev/mmcblk1 back_file=/tmp/lun0.img   mkdir /sys/kernel/config/usb_gadget/g$id cd /sys/kernel/config/usb_gadget/g$id   # Use NXP VID, i.MX8QXP PID echo 0x1fc9 > idVendor echo 0x12cf > idProduct   mkdir strings/0x409 echo 123456ABCDEF > strings/0x409/serialnumber echo NXP > strings/0x409/manufacturer echo "NXP iMX USB Composite Gadget" > strings/0x409/product   mkdir configs/c.1 mkdir configs/c.1/strings/0x409   echo 5 > configs/c.1/MaxPower echo 0xc0 > configs/c.1/bmAttributes   mkdir functions/mass_storage.1 echo $back_file > functions/mass_storage.1/lun.0/file ln -s functions/mass_storage.1 configs/c.1/   echo $udc_name > UDC First execute the script. After that insert the g_mass_storage module in the kernel by executing :- modprobe g_mass_storage file=/dev/mmcblk1 removable=1 In the dmesg output, you will see something like below:-   After that you can connect a C type USB cable to the USB1 port of imx93evk and the other end to any USB ports of a laptop. The moment it is connected, you would be able to see a USB drive similar to what you get when we connect a pen-drive. 

What is LGVL? LVGL is a graphics library to run on devices with limited resources. LVGL is fully open-source and has no external dependencies, works with any modern MCU or MPU, and can be used with any (RT)OS or bare metal setup. https://lvgl.io/   What is Framebuffer? The Linux framebuffer (fbdev) is a Linux subsystem used to show graphics on a display, typically manipulated on the system console   How to write on the frame buffer? The device is listed on de device list typically "fb0" on iMX.   1. Stop the window manager (Weston in our BSP) $ systemctl stop weston   2. Write random data on the frame buffer with the next command: $ cat /dev/urandom > /dev/fb0   You should see colored pixels on the screen   3. Restart the window manager. $ systemctl start weston     Cross-compiling the application   1. On the host computer we will clone the LGVL repo: $ git clone https://github.com/lvgl/lv_port_linux_frame_buffer.git -b release/v8.2 $ cd lv_port_linux_frame_buffer $ git submodule update --init --recursive 2. Configure the screen resolution, rotation, and the touch input.       2.1 The resolution is configured in lines 33 and 34 of the main.c disp_drv.hor_res = 1080; disp_drv.ver_res = 1920;           2.2 Rotation configured is on lines 32 and 57 of main.c. disp_drv.sw_rotate = 3; lv_disp_set_rotation(NULL, LV_DISP_ROT_270);     2.3 The touch input is configured on line 450 of lv_drv_conf.h # define EVDEV_NAME "/dev/input/event2"   Note: In my case is on /dev/input/event2 to check the inputs use the command "evtest"   3. Compile the application using the command "make"   Note: To compile the application on your host computer you have to set the environment.   4. Share the file called "demo" with your board and execute it on the board with the command $ ./demo   Note: You have to stop the weston service to run the application.     Notes: Tested on iMX8MN EVK with BSP 6.1.36 Works on Multimedia and Full image.

  Some customer need to config different I2C bus for their PMIC in DDR test period. There is a simple method can complete this, that is NXP DDR Config Tool. The tool download link is below: https://www.nxp.com/design/development-boards/i-mx-evaluation-and-development-boards/config-tools-for-i-mx-applications-processors:CONFIG-TOOLS-IMX I'm going to use the i.MX 93 EVK board here as a demonstration. On i.MX 93 EVK board, the default PMIC I2C Bus is I2C2, I will show you how to change I2C2 to I2C1, the other i2c bus is same.  Step 1 : Rework the board and make sure the PMIC is connected to I2C1. Remove R714 R715, connnect I2C1_SCL(C20) to U701 pin 41  and I2C1_SDA(C21) tp U701 pin 42. Step 2 : Setup I2C1 PinMux: Config Tool UI:   Advance -> IOMUX config   Command:           Address                Size               Value memory   set     0x443c0170            32                   0x10 memory   set     0x443c0174            32                   0x10 memory   set     0x443c0320            32                   0x40000b9e memory   set     0x443c0324            32                   0x40000b9e Step 3 : Set PMIC VDDQ as 1.1 V Config Tool UI:   Advance -> Custom PMIC initialization enabled   #  PMIC commands        Value 0         pmic_cfg             0x0025       /*I2C bus 1,  PMIC address 0x25 */ (0 for I2C1, 1 for I2C2, 2 for I2C3, 3 for I2c4 …) 1         pmic_set             0x0C29       /* BUCKxOUT_DVS0/1, preset_buck1=0.8V, preset_buck2=0.7V, preset_buck3=0.8V PCA9451_BUCK123_DVS, 0x29 */ 2         pmic_set             0x1118      /*  BUCK1OUT_DVS0=0.9V   PCA9451_BUCK1OUT_DVS0, 0x18 */ 3         pmic_set             0x1718      /*  BUCK3OUT_DVS0=0.9V   PCA9451_BUCK3OUT_DVS0, 0x18 */ 4         pmic_set             0x1428      /*  Set VDDQ to 1.1V  PCA9451_BUCK2OUT_DVS0, 0x28  */ PS : About pmic register, The first two bytes are the register address and the next two bytes are the register setting. Step 4 : Run the DDR "Firmware init test" and see the test result. The success log is as follows: DEBUG memtool.comm.serial_channel ==================hardware_init======================= DEBUG memtool.comm.serial_channel DEBUG memtool.comm.serial_channel Power up ddr... DEBUG memtool.comm.serial_channel DEBUG memtool.comm.serial_channel DDRMIX power on done... DEBUG memtool.comm.serial_channel DEBUG memtool.comm.serial_channel DDRPHY coldreset... DEBUG memtool.comm.serial_channel DEBUG memtool.comm.serial_channel DEBUG memtool.comm.serial_channel DEBUG memtool.comm.serial_channel ********Found PMIC PCA945X********** DEBUG memtool.comm.serial_channel DEBUG memtool.comm.serial_channel Set VDDQ to 1.1V for LPDDR4 DEBUG memtool.comm.serial_channel DEBUG memtool.comm.serial_channel ==================hardware_init exit==================    

In the IMX8MM SDK unfortunately we cannot find any example about of use a GPIO as an input with interrupt.  To use a GPIO as input with interrupt we need to keep in mind how the GPIO IRQs works in the ARM Cortex M4.   We can find in Table 7-2 (CM4 Interrupt Summary) of IMX8MMRM (IMX8MM Reference Manual) the GPIOs IRQs are divided by two parts:     Combined interrupt indication for GPIOn signal 0 throughout 15  Combined interrupt indication for GPIOn signal 16 throughout 31    This basically means, the pines of GPIOn from 0 to 15 are handled by Combined interrupt indication for GPIOn signal 0 throughout 15 and the pines from 16 to 31 are handled by Combined interrupt indication for GPIOn signal 16 throughout 31.    In SDK we can find these definitions in:  <SDK root>/devices/MIMX8MM6/MIMX8MM6_cm4.h (Remember this is for IM8MM SDK)    In this example I will use GPIO5_IO12 (ECSPI2_MISO) as Input with IRQ and GPIO5_IO11 (ECSPI_MOSI) as Output of IMX8MM-EVK. I will connect the Output to the Input and will see the behavior of the IRQ in Rising and Falling edge.    For this example I will connect ECSPI2_MOSI (GPIO5_IO11) to ECSPI_MISO (GPIO5_IO12):   See the below definitions:   #define IN_GPIO   GPIO5  This define the GPIO base of the IN pin  #define IN_GPIO_PIN  12u  This define the pin number (for in)  #define IN_IRQ  GPIO5_Combined_0_15_IRQn  This define the IRQ number (72 in this case)  #define GPIO_IRQ_HANDLER  GPIO5_Combined_0_15_IRQHandler  This is a "pointer" to function that will handle the interrupt  #define IN_NAME  "IN GPIO5_IO12"  This is only a name or description for the pin    See below definitions:    #define OUT_GPIO  GPIO5  This is the GPIO base of OUT pin  #define OUT_GPIO_PIN  11u  This define the pin number (for out)  #define OUT_NAME  "OUT GPIO5_IO11"  This is only a name or description for the pin      Now the below section is the IRQ handler (which was defined before)😞   The GPIO_ClearPinsInterruptFlags(IN_GPIO, 1u << IN_GPIO_PIN); refers to GPIOx_ISR register:      For this example, the IRQ Handler will print "IRQ detected ............" in each interrupt.    We will create two different GPIOs config, one for Output and other one for Input with IRQ Falling edge:    Then configure the GPIOs and IRQ:     EnableIRQ refers to enable the 72 IRQ.   GPIO_PortEnableInterrupts refers to GPIOx_IMR: Finally, the example put the out GPIO5_IO11 in High state and then in low state many. First the IRQ is configured as Falling edge, then as Rising edge.     I will attach the complete source file.    To compile it you can use ARMGCC toolchain directly, but I like to use VSCode with MCUXpresso integration.  Once, when you have your .bin file (in my case igpio_led_output.bin) you can load to board with UUU tool: In your Linux machine: sudo uuu -b fat_write igpio_led_output.bin mmc 2:1 gpio.bin In U-boot board: u-boot=> fastboot 0   Then, when the .bin file was loaded, you can load to the CORTEX M4 in U-boot whit: u-boot=> fatload mmc 2:1 ${loadaddr} gpio.bin 7076 bytes read in 14 ms (493.2 KiB/s) u-boot=> cp.b 0x80000000 0x7e0000 0x10000 u-boot=> bootaux 0x7e0000 ## No elf image ar address 0x007e0000 ## Starting auxiliary core stack = 0x20020000, pc = 0x1FFE02CD... u-boot=>   NOTE: You can load the binary to cortex m4 with Custom bootscripts for practicity.   Once the binary loaded in M4 core you should see in seria terminal this logs (Remember GPIO5_IO11 and GPIO5_IO12 must be connected to get the same logs):    And the logs when you disconnect the GPIO5_IO11 and GPIO5_IO12 in execution time:  🔴Disconnection (Red color) 🔵Reconnection (Blue color)   I hope this can helps.     Best regards!    Salas. 

Information about the transition from the NXP Demo Experience to GoPoint for i.MX Application Processors.

BSP: L6.1.36 Some customer need use adb under usb ffs. The adb in Yocto can greatly improves development efficiency. This is a demo for enabling adb on Yocto.   Yocto local.conf IMAGE_INSTALL:append = "android-tools android-tools-adbd" PREFERRED_PROVIDER_android-tools-conf = "android-tools-conf-configfs"   Test script for launching adbd modprobe g_ffs idVendor=0x1fc9 idProduct=0x0146 iSerialNumber="ZhimingLiu" mkdir -p /dev/usb-ffs/adb mount -t functionfs adb /dev/usb-ffs/adb -o uid=2000,gid=2000 adbd &   Test on Windows: PS C:\Users\Administrator\Desktop\platform-tools> .\adb.exe devices List of devices attached ZhimingLiu device PS C:\Users\Administrator\Desktop\platform-tools> .\adb.exe shell sh-5.2# uname -a Linux imx8mp-lpddr4-evk 6.1.36+g04b05c5527e9 #1 SMP PREEMPT Fri Nov 24 04:46:22 UTC 2023 aarch64 GNU/Linux sh-5.2# ls config ffs t.sh test2.sh sh-5.2# cd / sh-5.2# ls bin dev home lost+found mnt proc run srv tmp usr boot etc lib media opt root sbin sys unit_tests var sh-5.2#

Platform: Demo images, i.MX8MPlus EVK   Some customer need test ffs gadget function on i.MX8MPlus EVK. Here is demo for ffs test, please connect EVK and Ubuntu PC before test.   Test script: #!/bin/sh # Setup the device (configfs) modprobe libcomposite mkdir -p config mount none config -t configfs cd config/usb_gadget/ mkdir g1 cd g1 echo 0x1fc9 >idVendor echo 0x0146 >idProduct mkdir strings/0x409 echo 12345 >strings/0x409/serialnumber echo "Signal 11" >strings/0x409/manufacturer echo "Test" >strings/0x409/product mkdir configs/c.1 mkdir configs/c.1/strings/0x409 echo "Config1" >configs/c.1/strings/0x409/configuration # Setup functionfs mkdir functions/ffs.usb0 ln -s functions/ffs.usb0 configs/c.1 cd ../../../ mkdir -p ffs mount usb0 ffs -t functionfs cd ffs ffs-test 64 & # from the Linux kernel, with mods! sleep 3 cd .. # Enable the USB device echo 38100000.usb > config/usb_gadget/g1/UDC   EVK log root@imx8mpevk:~# ./test2.sh [ 17.859597] file system registered ffs-test: dbg: ep0: writing descriptors (in v2 format) ffs-test: dbg: ep0: writing strings ffs-test: dbg: ep1: starting ffs-test: dbg: ep2: starting ffs-test: dbg: ep1: starts ffs-test: dbg: ep0: starts ffs-test: dbg: ep2: starts Event BIND Event ENABLE Ubuntu PC log: lzm@lzm-GL552VW:~$ lsusb -D /dev/bus/usb/001/008 Device: ID 1fc9:0146 NXP Semiconductors Test Device Descriptor: bLength 18 bDescriptorType 1 bcdUSB 2.10 bDeviceClass 0 bDeviceSubClass 0 bDeviceProtocol 0 bMaxPacketSize0 64 idVendor 0x1fc9 NXP Semiconductors idProduct 0x0146 bcdDevice 6.01 iManufacturer 1 Signal 11 iProduct 2 Test iSerial 3 12345 bNumConfigurations 1 Configuration Descriptor: bLength 9 bDescriptorType 2 wTotalLength 0x0020 bNumInterfaces 1 bConfigurationValue 1 iConfiguration 4 Config1 bmAttributes 0x80 (Bus Powered) MaxPower 2mA Interface Descriptor: bLength 9 bDescriptorType 4 bInterfaceNumber 0 bAlternateSetting 0 bNumEndpoints 2 bInterfaceClass 255 Vendor Specific Class bInterfaceSubClass 0 bInterfaceProtocol 0 iInterface 5 Source/Sink Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x81 EP 1 IN bmAttributes 2 Transfer Type Bulk Synch Type None Usage Type Data wMaxPacketSize 0x0200 1x 512 bytes bInterval 0 Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x01 EP 1 OUT bmAttributes 2 Transfer Type Bulk Synch Type None Usage Type Data wMaxPacketSize 0x0200 1x 512 bytes bInterval 1 Binary Object Store Descriptor: bLength 5 bDescriptorType 15 wTotalLength 0x0016 bNumDeviceCaps 2 USB 2.0 Extension Device Capability: bLength 7 bDescriptorType 16 bDevCapabilityType 2 bmAttributes 0x0000010e BESL Link Power Management (LPM) Supported BESL value 256 us SuperSpeed USB Device Capability: bLength 10 bDescriptorType 16 bDevCapabilityType 3 bmAttributes 0x00 wSpeedsSupported 0x000f Device can operate at Low Speed (1Mbps) Device can operate at Full Speed (12Mbps) Device can operate at High Speed (480Mbps) Device can operate at SuperSpeed (5Gbps) bFunctionalitySupport 1 Lowest fully-functional device speed is Full Speed (12Mbps) bU1DevExitLat 0 micro seconds bU2DevExitLat 0 micro seconds Device Status: 0x0001 Self Powered  

Usually, device tree source files are not a signal pure dts file. It could include dtsi, dts or C code heads .h files. Need C compiler finish the pre-compile to a pure dts file first. It is integrated inside the like Linux build system(Makefile, etc.). This document shows the original way to compile device tree. This document will show compile device tree under windows.    

How to use UART4 on iMX8M from Linux User Space   The UART4 on iMX8MM-EVK and iMX8MN-EVK are thinking of debugging the M core which is not usable on Linux user space by default on pre-compiled images.   To use the UART4 on Linux user space you have to do the next modifications on the device tree and atf to assign that peripheral to Linux User Space     https://github.com/nxp-imx/imx-atf/blob/lf_v2.6/plat/imx/imx8m/imx8mm/imx8mm_bl31_setup.c     iMX8MN-EVK   imx8mn_bl31_setup.c   https://github.com/nxp-imx/imx-atf/blob/lf_v2.6/plat/imx/imx8m/imx8mn/imx8mn_bl31_setup.c   /* Master domain assignment */ RDC_MDAn(RDC_MDA_M7, DID1), /* peripherals domain permission */ - RDC_PDAPn(RDC_PDAP_UART4, D1R | D1W), + RDC_PDAPn(RDC_PDAP_UART4, D0R | D0W), RDC_PDAPn(RDC_PDAP_UART2, D0R | D0W), RDC_PDAPn(RDC_PDAP_RDC, D0R | D0W | D1R),       Device tree configurations for iMX8MN-EVK   iMX8MN-EVK.dtsi   https://github.com/nxp-imx/linux-imx/blob/lf-6.1.y/arch/arm64/boot/dts/freescale/imx8mn-evk.dtsi   &uart3 { pinctrl-names = "default"; pinctrl-0 = <&pinctrl_uart3>; assigned-clocks = <&clk IMX8MN_CLK_UART3>; assigned-clock-parents = <&clk IMX8MN_SYS_PLL1_80M>; uart-has-rtscts; status = "okay"; }; + &uart4 { + pinctrl-names = "default"; + pinctrl-0 = <&pinctrl_uart4>; + assigned-clocks = <&clk IMX8MN_CLK_UART4>; + assigned-clock-parents = <&clk IMX8MN_SYS_PLL1_80M>; + status = "okay"; + }; ********************** pinctrl_uart3: uart3grp { fsl,pins = < MX8MN_IOMUXC_ECSPI1_SCLK_UART3_DCE_RX 0x140 MX8MN_IOMUXC_ECSPI1_MOSI_UART3_DCE_TX 0x140 MX8MN_IOMUXC_ECSPI1_SS0_UART3_DCE_RTS_B 0x140 MX8MN_IOMUXC_ECSPI1_MISO_UART3_DCE_CTS_B 0x140 >; }; + pinctrl_uart4: uart4grp { + fsl,pins = < + MX8MN_IOMUXC_UART4_RXD_UART4_DCE_RX 0x140 + MX8MN_IOMUXC_UART4_TXD_UART4_DCE_TX 0x140 + >; + };   iMX8MM-EVK   https://github.com/nxp-imx/imx-atf/blob/lf_v2.6/plat/imx/imx8m/imx8mm/imx8mm_bl31_setup.c   imx8mm_bl31_setup.c   /* Master domain assignment */ RDC_MDAn(RDC_MDA_M7, DID1), /* peripherals domain permission */ - RDC_PDAPn(RDC_PDAP_UART4, D1R | D1W), + RDC_PDAPn(RDC_PDAP_UART4, D0R | D0W), RDC_PDAPn(RDC_PDAP_UART2, D0R | D0W), RDC_PDAPn(RDC_PDAP_RDC, D0R | D0W | D1R),   Device tree configurations for iMX8MM-EVK   iMX8MM-EVK.dtsi   https://github.com/nxp-imx/linux-imx/blob/lf-6.1.y/arch/arm64/boot/dts/freescale/imx8mm-evk.dtsi   &uart3 { pinctrl-names = "default"; pinctrl-0 = <&pinctrl_uart3>; assigned-clocks = <&clk IMX8MM_CLK_UART3>; assigned-clock-parents = <&clk IMX8MM_SYS_PLL1_80M>; uart-has-rtscts; status = "okay"; }; + &uart4 { + pinctrl-names = "default"; + pinctrl-0 = <&pinctrl_uart4>; + assigned-clocks = <&clk IMX8MM_CLK_UART4>; + assigned-clock-parents = <&clk IMX8MM_SYS_PLL1_80M>; + status = "okay"; + }; ********************** pinctrl_uart3: uart3grp { fsl,pins = < MX8MM_IOMUXC_ECSPI1_SCLK_UART3_DCE_RX 0x140 MX8MM_IOMUXC_ECSPI1_MOSI_UART3_DCE_TX 0x140 MX8MM_IOMUXC_ECSPI1_SS0_UART3_DCE_RTS_B 0x140 MX8MM_IOMUXC_ECSPI1_MISO_UART3_DCE_CTS_B 0x140 >; }; + pinctrl_uart4: uart4grp { + fsl,pins = < + MX8MM_IOMUXC_UART4_RXD_UART4_DCE_RX 0x140 + MX8MM_IOMUXC_UART4_TXD_UART4_DCE_TX 0x140 + >; + };   iMX8MP-EVK   https://github.com/nxp-imx/imx-atf/blob/lf_v2.6/plat/imx/imx8m/imx8mp/imx8mp_bl31_setup.c   imx8mp_bl31_setup.c   RDC_MDAn(RDC_MDA_M7, DID1), RDC_MDAn(RDC_MDA_LCDIF, DID2), RDC_MDAn(RDC_MDA_LCDIF2, DID2), RDC_MDAn(RDC_MDA_HDMI_TX, DID2), /* peripherals domain permission */ + RDC_PDAPn(RDC_PDAP_UART4, D0R | D0W), RDC_PDAPn(RDC_PDAP_UART2, D0R | D0W), RDC_PDAPn(RDC_PDAP_WDOG1, D0R | D0W), RDC_PDAPn(RDC_PDAP_RDC, D0R | D0W | D1R),   Device tree configurations for iMX8MP-EVK   iMX8MP-EVK.dts   https://github.com/nxp-imx/linux-imx/blob/lf-6.1.y/arch/arm64/boot/dts/freescale/imx8mp-evk.dts   &uart3 { pinctrl-names = "default"; pinctrl-0 = <&pinctrl_uart3>; assigned-clocks = <&clk IMX8MP_CLK_UART3>; assigned-clock-parents = <&clk IMX8MP_SYS_PLL1_80M>; fsl,uart-has-rtscts; status = "okay"; }; + &uart4 { + pinctrl-names = "default"; + pinctrl-0 = <&pinctrl_uart4>; + assigned-clocks = <&clk IMX8MP_CLK_UART4>; + assigned-clock-parents = <&clk IMX8MP_SYS_PLL1_80M>; + status = "okay"; + }; ************************************ pinctrl_uart3: uart3grp { fsl,pins = < MX8MP_IOMUXC_ECSPI1_SCLK__UART3_DCE_RX 0x140 MX8MP_IOMUXC_ECSPI1_MOSI__UART3_DCE_TX 0x140 MX8MP_IOMUXC_ECSPI1_SS0__UART3_DCE_RTS 0x140 MX8MP_IOMUXC_ECSPI1_MISO__UART3_DCE_CTS 0x140 >; }; + pinctrl_uart4: uart4grp { + fsl,pins = < + MX8MP_IOMUXC_UART4_RXD__UART4_DCE_RX 0x140 + MX8MP_IOMUXC_UART4_TXD__UART4_DCE_TX 0x140 + >; + };     After compiling the image with the changes previously shown, we obtained this result:      

Board : i.MX93 EVK BSP: imx L6.1.1-1.0.0 Gui guider: 1.6.1   We have a GUI software tool called GUI Guider. It is a user-friendly graphical user interface development tool from NXP that enables the rapid development of high quality displays with the open-source LVGL graphics library. The GUI demo can run on the i.MX93EVK board. (https://www.nxp.com/design/software/development-software/gui-guider:GUI-GUIDER)   This document will show you an example how the buttons(gpio) on the EVK to interacting with the GUI. Basically, customer could use the same method to use the gpio pins to control everything.   On the i.MX93 EVK board, there are two buttons BTN1 and BTN2. They are connected to GPIO IO23 and GPIO IO24. Below is the schematic.    Buttons on the board.      SW1005 on the board   In the EVK's device tree file, need to change the pinmux for the two buttons like this: pinctrl_spdif: spdifgrp { fsl,pins = < // MX93_PAD_GPIO_IO22__SPDIF_IN 0x31e // MX93_PAD_GPIO_IO23__SPDIF_OUT 0x31e MX93_PAD_GPIO_IO23__GPIO2_IO23 0x31e MX93_PAD_GPIO_IO24__GPIO2_IO24 0x31e >; note: all the pins are defined in imx93-pinfunc.h.   For getting the input value of the buttons in user's space, I use the sysfs gpio. Build the imx-image-multimedia image first and then select the GPIO_SYSFS in kernel's menuconfig.   $ DISTRO=fsl-imx-xwayland MACHINE=imx93evk source imx-setup-release.sh -b build-xwayland $ bitbake imx-image-multimedia   After the build completed, go to the kernel's menuconfig to select the GPIO sysfs. $ bitbake linux-imx -c menuconfig [*] General setup-> Configure standard kernel features (expert users) [*] Device Drivers->GPIO Support-> /sys/class/gpio/... (sysfs interface)   Build the whole image again by "$ bitbake imx-image-multimedia".   Using the UUU to program the image to the EMMC on the EVK board. uuu -b emmc_all imx-image-multimedia-imx93evk.rootfs.wic.zst   Connect the LVDS to the board. Use the corresponding dtb to boot the board. In u-boot, set the dtb file. => setenv fdtfile imx93-11x11-evk-boe-wxga-lvds-panel.dtb => saveenv   Then restart the board. After the board boot up, it will look like below.     You need to calibrate the LVDS touch screen before it can normally use. Please use this command: $ weston-touch-calibrator LVDS-1     Now, build the GUI guider example. I use the Air Conditioner example. Download the GUI guider from the gui-guider web page: https://www.nxp.com/design/software/development-software/gui-guider:GUI-GUIDER   Follow the steps from the below web page to build the i.MX BSP and the gui example code. https://docs.nxp.com/bundle/GUIGUIDERUG-1.6.1/page/topics/yocto.html   After the gui-guider build completed, use the 'scp' command to transfer the gui_guider executable file to the board. Execute the command on your host PC like this: $ scp bld-imx93evk/tmp/work/armv8a-poky-linux/gui-guider/1.6.0-r0/image/usr/bin/gui_guider root@<Your Board IP address>:/ Note: You could use a router to connect your board and your host PC. They are on the same network so could use the 'scp' command to transfer the file to your board.   On your board, type the following commands to execute the gui. $ chmod 755 gui_guider $ ./gui_guider &   Then the GUI is running like this:   Now, let me explain how to find out the gpio number. Type the following command to show the mapping addresses of gpio. root@imx93evk:/# cat /sys/kernel/debug/gpio gpiochip3: GPIOs 0-31, parent: platform/47400080.gpio, 47400080.gpio: gpiochip0: GPIOs 32-63, parent: platform/43810080.gpio, 43810080.gpio: gpiochip1: GPIOs 64-95, parent: platform/43820080.gpio, 43820080.gpio: gpio-64 ( |cd ) in hi IRQ ACTIVE LOW gpio-71 ( |regulator-usdhc2 ) out lo gpiochip2: GPIOs 96-127, parent: platform/43830080.gpio, 43830080.gpio: gpiochip6: GPIOs 472-477, parent: i2c/0-001a, wm8962, can sleep: gpiochip5: GPIOs 478-487, parent: platform/adp5585-gpio.1.auto, adp5585-gpio, can sleep: gpio-479 ( |regulator-audio-pwr ) out hi gpio-483 ( |regulator-can2-stby ) out hi ACTIVE LOW gpio-486 ( |enable ) out hi gpiochip4: GPIOs 488-511, parent: i2c/1-0022, 1-0022, can sleep: gpio-492 ( |Headphone detection ) in lo IRQ gpio-501 ( |? ) out hi gpio-502 ( |regulator-vdd-12v ) out hi gpio-505 ( |reset ) out lo gpio-507 ( |? ) out hi gpio-508 ( |reset ) out lo ACTIVE LOW   The gpio pins of two buttons are GPIO2_IO23 and GPIO2_IO24. They are belongs to gpio2. In the imx93.dtsi, the gpio2's address is "gpio2: gpio@43810080". So, base on the information output from "/sys/kernel/debug/gpio", the gpio2 is mapping to "gpiochip0: GPIOs 32-63". So, the GPIO2_IO23 is 32+23=55, and the GPIO2_IO24 is 32+24=56.   To verify the gpio number is correct or not. We could do the following test. root@imx93evk:/# echo 55 > /sys/class/gpio/export root@imx93evk:/# echo in > /sys/class/gpio/gpio55/direction root@imx93evk:/# echo 56 > /sys/class/gpio/export root@imx93evk:/# echo in > /sys/class/gpio/gpio56/direction   Then, run these two commands to check the values. root@imx93evk:/# cat /sys/class/gpio/gpio55/value root@imx93evk:/# cat /sys/class/gpio/gpio55/value   When the button is not pressed, the value is 1. When press the button, the value is 0.  We could add the same in the GUI's custom.c. Open the GUI Guider software and add the code in the custom.c. /********************* * INCLUDES *********************/ #include <stdio.h> #include <stdlib.h> #include <unistd.h> #include <errno.h> #include <fcntl.h> #include "lvgl.h" #include "custom.h" #include "ui_Aircon.h" #include "guider_customer_fonts.h" /********************** * STATIC VARIABLES **********************/ int fdbtn1,fdbtn2,fdgpio; int btn1_pressed; int btn2_pressed; char btn1_value, btn2_value; void custom_func(void) { fdbtn1 = open("/sys/class/gpio/gpio55/value", O_RDWR); fdbtn2 = open("/sys/class/gpio/gpio56/value", O_RDWR); read(fdbtn1, &btn1_value, 1); read(fdbtn2, &btn2_value, 1); if(btn1_value=='0' && btn1_pressed) { btn1_pressed=0; ui_aircon_update_temp(0, kAIRCON_TempUp); } if(btn1_value=='1') btn1_pressed=1; if(btn2_value=='0' && btn2_pressed) { btn2_pressed=0; ui_aircon_update_temp(0, kAIRCON_TempDown); } if(btn2_value=='1') btn2_pressed=1; close(fdbtn1); close(fdbtn2); } void custom_init(lv_ui *ui) { fdbtn1 = open("/sys/class/gpio/gpio55/value", O_WRONLY); if (fdbtn1 == -1) { fdgpio = open("/sys/class/gpio/export", O_WRONLY); write(fdgpio,"55",3); write(fdgpio,"56",3); close(fdgpio); fdgpio = open("/sys/class/gpio/gpio55/direction", O_WRONLY); write(fdgpio,"in",3); close(fdgpio); fdgpio = open("/sys/class/gpio/gpio56/direction", O_WRONLY); write(fdgpio,"in",3); close(fdgpio); } else close(fdbtn1); ... ... ... ...   Add the custom_func() in the custom.h. #ifndef __CUSTOM_H_ #define __CUSTOM_H_ #ifdef __cplusplus extern "C" { #endif #include "gui_guider.h" void custom_init(lv_ui *ui); + void custom_func(void);   Also, need to add the custom function() into the dead loop in main.c.   To modify the code, bld-imx93evk$ vim tmp/work/armv8a-poky-linux/gui-guider/1.6.0-r0/gui-guider-1.6.0/ports/linux/main.c   while(1) { + custom_func(); // <--- Add the custom function here. /* Periodically call the lv_task handler. * It could be done in a timer interrupt or an OS task too.*/ time_till_next = lv_wayland_timer_handler(); #if LV_USE_VIDEO video_play(&guider_ui); #endif /* Run until the last window closes */ if (!lv_wayland_window_is_open(NULL)) { break; }   Re-build the code after modified. bld-imx93evk$ bitbake gui-guider -c compile -f   Build the whole image again. bld-imx93evk$ bitbake gui-guider Then use the 'scp' command to transfer the new gui-guider file to the board.   Finally, you can use the buttons on the EVK board to set the temperature up and down.                          

i.MX93 DDR stress test tool is different with previous i.MX tool. This Chinese article describe how to debug i.MX93 DDR and introduce DDR config tool usage.

On this tutorial we will review the implementation of Flutter on the i.MX8MP using the Linux Desktop Image. Please find more information about Flutter using the following link: Flutter: Option to create GUIs for Embedded System... - NXP Community Requirements: Evaluation Kit for the i.MX 8M Plus Applications Processor. (i.MX 8M Plus Evaluation Kit | NXP Semiconductors) NXP Desktop Image for i.MX 8M Plus (GitHub - nxp-imx/meta-nxp-desktop at lf-6.1.1-1.0.0-langdale) Note: This tutorial is based on the NXP Desktop Image with Yocto version 6.1.1 – Langdale. Steps: 1. First, run commands to update packages. $ sudo apt update $ sudo apt upgrade 2. Install Flutter for Linux using the following command. $ sudo snap install flutter --classic 3. Run the command to verify the correct installation. $ flutter doctor With this command you will find information about the installation. The important part for our purpose is the parameter "Linux toolchain - develop for Linux desktop". 4. Run the command “flutter create .” to create a flutter project, this framework will create different folders and files used to develop the application.  $ cd Documents $ mkdir flutter_hello $ cd flutter_hello $ flutter create .​ 5. Finally, you can run the “hello world” application using: $ flutter run Verify the program behavior incrementing the number displayed on the window.