How do I get a reliable K22 connection from the LS102A-IOT Reference Design?

cancel
Showing results for 
Search instead for 
Did you mean: 

How do I get a reliable K22 connection from the LS102A-IOT Reference Design?

999 Views
tafthorne
Contributor III

I have a TechNexio freescale LS1021A-IOT reference design box but I cannot get it to reliably come up and provide a serial connection.  This is using the supplied SDHC card, with the supplied image.  I have got a serial console to come up a handful of times in the last two days but I am not sure what happened those times to make it work. 

I have tried on both Ubuntu and Windows 7.  Almost every time the box is powered up an mBed Serial Port and MBED storage drive are detected over the USB0 K22 connection.  Most times I can get the K22 LED to flicker when I am typing in a connected console terminal.  Seldom will any output come from the box. 

What am I doing wrong? 

I have tried following the instructions in the QorIQ LS1021A-IOT Gateway Reference Design Getting Started Guide (Document Number: Ls1021A-IOTGS Rev 2, 02/2015).  I tried using different USB ports on the PCs.  Reinstalling the USB drivers.  Connecting an HDMI monitor and USB keyboard; the monitor never displays but the keyboard will respond to Caps Lock when the terminal works but not the rest of the time.  I have wiggled the SD Card, used dd to copy it.  Checked it reads OK under Linux via a SD Card reader. 

The status LEDs that come on are always K22, PWR and LED0, never DEBUG. 

The supplied SD card seems to have on it 3 partitions:

  • 4.2MB Free
  • 3.9GB FAT
  • 4GB Free

The FAT partition has 3 files named; fsl-image-rds-iot-ls1021aiot.ext2.gz.u-boot, uImage-ls1021aiot.bin and uImage-ls1021aiot.dtb. 

On the odd occasion it booted I was able to reboot to exit Linux, catch the uBoot and look at the startup scripts.  I can type those out from my notes if it would be helpful. 

Labels (1)
0 Kudos
8 Replies

647 Views
pranavmadhu
Contributor IV

Hi Thomas,

In linux, you get console through ttyACM0, ttyACM1 etc. not through ttyUSB0.

In linux machine, to flash u-boot to sd card, use the command below

     " sudo dd if=/path/to/u-boot.bin of=/dev/<sd card node> bs=512 seek=8 oflag=dsync conv=notrunc"

the card node may be like /dev/sdb, /dev/mmcblk etc. care should be taken, that if sd card is at node sdb, then sda will be your hard-disk partition which is used by linux, donot write u-boot their.

Now insert sdcard into board and now you can boot the board.

In linux you can use minicom to get console, set the serial interface of minicom as /dev/ttyACM0

647 Views
Pavel
NXP TechSupport
NXP TechSupport

The LS1043A does not have limitation for hot plug connection on the SDHC controller.


Have a great day,
Pavel Chubakov

-----------------------------------------------------------------------------------------------------------------------
Note: If this post answers your question, please click the Correct Answer button. Thank you!
-----------------------------------------------------------------------------------------------------------------------

0 Kudos

647 Views
tafthorne
Contributor III

My question is about the LS1021A-IOT board.  I am not trying to access the SD card via USB, I wanted to know why the serial console only showed output intermittently. 

0 Kudos

647 Views
Pavel
NXP TechSupport
NXP TechSupport

Is there new COM port in Windows Device manager/Control panel/SerialPorts?

See attached file.


Have a great day,
Pavel Chubakov

-----------------------------------------------------------------------------------------------------------------------
Note: If this post answers your question, please click the Correct Answer button. Thank you!
-----------------------------------------------------------------------------------------------------------------------

0 Kudos

647 Views
tafthorne
Contributor III

Yes, there is a COM port in Windows.  It shows up every time.  Every time it is port 16.  I have tried connecting to several different USB ports on the same PC. 

The device also comes up under Linux as ttyACM0 as expected.  Under Linux there is sometimes a delay of several seconds before I can open the COM port. 

On Windows and Linux the appearance of the COM port does not not seem to indicate there will be any output to it from the board, which is my problem. 

On both Windows and Linux the COM port or ttyACM0 do not appear until power is applied to the board.  The Getting Started Guide seems to suggest that the device should appear before mains power is applied; however this has not been my observation.  !

0 Kudos

647 Views
addiyi
NXP Employee
NXP Employee

For Windows please try installing Windows serial configuration - Handbook | mbed

Adrian

647 Views
tafthorne
Contributor III

I got one more successful boot.  I removed the SD card.  Connected the USB (nothing in Device Manager).  Connected mains power (mbed Serial Port appears in device manager).  Connected Putty.  Plugged in SD card, boot message immediately started to get posted. 

Trying this again it seems repeatable iff I close Putty, remove the USB cable, remove the power, remove the SD card and then start the sequence again.  This seems much more fragile than the Getting Started Guide implies. 
Is it safe for me to continue booting without the SD card in place and then insert it after power on? 

0 Kudos

647 Views
tafthorne
Contributor III

I had already done so twice.  This time it seemed happy to detect the device without mains power being applied. 

The first time I applied power after installing the drivers again I was able to get output on the serial port.  I let the device finish booting from the SD card and then removed the power.  When I re-applied the power we were back in the problem state, not output on the serial port. 

After waiting a couple of minutes I closed down Putty, disconnected the mains power, unplugged the USB port and watched the device vanish from Device Manager > Ports.  Then I plugged the USB cable back in and nothing was registered this time.  Waited a while, applied mains power and got a USB not responding message up in Windows. 

For the Third attempt I disconnected everything.  Applied mains power, reconnected the USB and spotted the device coming up in Device Manager.    Attempted to connect to the COM port and no output was given. 

Fourth attempt I disconnected everything.  Waited a few seconds and plugged in the USB cable, nothing comes up in Device Manager again.  I attempted to run the Driver Install a second time but I get a message stating "The driver could not be installed. No mbed Microcontrollers were found."  Tried three different USB ports on the Windows machine with the same result.

In summary.  1 working boot and 3 subsequent failures.  That matches the memory I have from the past few days on both Windows and Linux platforms. 

0 Kudos