LPUART1 in RT1020-EVK

[Graciano]

Hi every one.

I have been working with MIMIXRT1020-EVK and I did to load the examples of LPUART1, I´m using in the Arduino conecctor J17 in pin 4 connected to RX of ESP32 and pin 6 to TX of ESP32,

I ran the examples  and I found out the input of data is by console and  not for the pin 4 of the J17, I would like to know if the LPUART1 is debug console?

I should prove with another LPUART?

What is the instructions about recept of the PIN 4 in J17?

I used the examples of MCUXpresso 11.3, te examples are LPUART_POLLING, LPUART_INTERRUP, LPUART_TRANSFERT_INTERRUPT.

The pin 4 is for LPUART1?

Once time I have modified the program of LPUART_INTERRUPT writing readByte() by the LPUART1, I can see the data received by the ESP32 in 9600 bauds, when I configure to 115200 baudios I cannot them and I only see the data input by keyboard and I need to see the data receivede by ESP32.

Why I cannot to see the data input of ESP32?

Thankyou.

[kerryzhou]

Hi Graciano,

  Next time, when you have the RT questions, please create it in this community:

https://community.nxp.com/t5/i-MX-RT/bd-p/imxrt

  Now, answer your questions:

1. About the MIMIXRT1020-EVK load the examples of LPUART1.
The MIMXRT1020-EVK board already have the on board debugger and the virtual Com port, the Virtual com port just connect to the :
GPIO_AD_B0_07(UART1_RXD) and GPIO_AD_B0_06(UART1_TXD)

So, if you want to use the external VCOM tool to connect J17_4 and J17_6, it is also correct.
But, you need to disconnect the on board virtual com port: J25,J26
BTW, when you connect to external VCOM tool, please note, RT UART_TX connect to your external tool RX, RT UART_TX connect to your external tool TX.

2. You don't need to use other LPUART, just LPUART 1 is Ok
3. J17_4 is just GPIO_AD_B0_07(UART1_RXD), J17_6 is GPIO_AD_B0_06(UART1_TXD)
Your issue is, misconnection to the external module, TX->RX, RX->TX, and disconnect on board VCOM port.
4. The SDK code is OK, in fact, you also can don't use the external com port, just use the on board debugger virtual com port is OK.
5. About the 115200, you even can run the SDK helloworld, and use the PC side tool, eg Tera Term to receive the UART data, if your ESP32 can't receive it, you can check the ESP32 RX data pin, whether that line have wave and correct, then you need to check your external module.

Wish it helps you!
If you still have questions about it, please kindly let me know.
Kerry