A9 UART6 and Udoobuntu

Dear Andrea, in fact I have not tried it with RC2. With RC1 the uart was not working and when I applied the patch it was working perfectly. I am a little busy at the moment, but as soon as I can I will try with RC2.
Cheers,
J

 

I tested RC2 today.

/dev/ttymxc5 is exposed to user space after device tree configuration.
Device Tree default provides UART with flow control CTS and RTS.
UDOO NEO successfully transmits, however it still does not receive.
Doesn't matter whether flow control is used or not.

On A9 Debug port you can still observe this:

Code:

[ 1927.078992] imx-uart 22a0000.serial: Rx FIFO overrun
[ 1927.110463] imx-uart 22a0000.serial: Rx FIFO overrun
[ 1927.139036] imx-uart 22a0000.serial: Rx FIFO overrun
[ 1927.169728] imx-uart 22a0000.serial: Rx FIFO overrun

BR,
1chi

 

After this result, did you try the patch to see if it works on RC2?

 

No, I did not apply the patch.
Still, I'm quiet sure that it works, since the patch is effectively deactivating the DMA.

This is not an option for me, since I have a huge amount of data to be transferred at low baudrate.
For now, I'm using UART5 from the A9 and UART6 from the M4 (requires to modify MQX).
UART1 and UART2 are in default configuration.

 

Is there a way to apply this patch without compile of the kernel?

 

I have loaded and tested the RC2 (downloaded from http://www.udoo.org/downloads/) and the 'imx-uart 22a0000.serial: Rx FIFO overrun' problem is not solved. I haven't applied the patch.

Is it possible apply the patch modifying the tool 'mkudoobuntu' ( http://www.udoo.org/docs-neo/Advanced_Topics/Compile_UDOObuntu_(complete_bootable_image).html )?

 

As far as I know, applying the patch and recompiling the kernel is the only way to get it working.
@Andrea Rovai I think somebody from the UDOO Team should communicate the problem to NXP, since it is bug in their kernel implementation...

 

How about a request from us the Users to the Udoo team to release a minor update to RC2 to correct this annoying little serial port problem. Does anyone else out there agree?

 

Hello,

I have detected 2 problems in the Ubuntu since I have applied the patch to enable the second serial port:

1. The keyboard and the mouse are not recognised for the Ubuntu.
2. The rc scripts are executed two times.

To compile the kernel I have followed the instructions of the page 'Compile Linux Kernel' ( http://www.udoo.org/docs-neo/Advanced_Topics/Compile_Linux_Kernel.html )

Do somebody have the same problems?

 

I just tried to assign uart6 to A9 pins 33,32,31,30 using the device three utility.
Apparently I can see the device in /dev/ttymxc5 nevertheless connecting a GPS receiver to pins 31 and 30 and using minicom -D /dev/ttymxc5 -b 4800 nothing I can't read data. The GPS works perfectly if connected to the Serial0 of the M4 side.
Any suggestion? I don't like to use a usbserial on Udoo-neo having a uart available or lock the M4 to a simple read from Serial0 and write to Serial task.
Cheers.
-- Raffaele

 

You can try testing the correct working of the Serial 6 by matching physically the pins between Arduino M4 and A9 .

UART 6 <-----> Serial0

 

UART 6 is not working in Udoobuntu 2 RC2, you still have to patch it:

 

We have retested the functioning in this specific case:

• UART 6 connected to Serial0 Arduino. We manage with minicom to read and write data. Are you sure you didn't spoil UART 6 by attaching something strange to it?

 

Well I tried it but I cannot read anything coming out of the Serial0 with UART6. I did not try to get data in. I tried to read Serial0 with TTL to USB and that works. I cannot read Serial0 with UART6.

My steps:

Activated UART6 through Device Tree Editor web.
Full reboot of Neo
Connected pin UART6_TX_DATA (pin 31) with UART5_RX (pin 0)
Connected pin UART_RX_DATA (pin 30) with UART5_TX (pin 1)
Made a Arduino sketch sending data to Serial0 and blink led 13 (see code)
Did a reboot to be sure.
I get a blinking led 13
In Linux did dmesg | grep ttym
got as result:

Code:

[    0.000000] Kernel command line: console=ttymxc0,115200 root=/dev/mmcblk0p2 rootwait rw ${mmcrootfstype} uart_from_osc clk_ignore_unused cpuidle.off=1 consoleblank=0
[    0.419599] 2020000.serial: ttymxc0 at MMIO 0x2020000 (irq = 58, base_baud = 1500000) is a IMX
[    1.215871] console [ttymxc0] enabled
[    1.220276] 22a0000.serial: ttymxc5 at MMIO 0x22a0000 (irq = 49, base_baud = 1500000) is a IMX

minicom -D /dev/ttymxc5
No output :-(

Code:

Welcome to minicom 2.7
OPTIONS: I18n
Compiled on Jan  1 2014, 17:08:55.
Port /dev/ttymxc5, 20:39:27

Press CTRL-A Z for help on special keys

What am I doing wrong? I switched the wires but that didn't help too (as expected). started minicom with sudo also did not help.
Next step is to read the data with TTL to USB converter, see if that is working.
EDIT:
When I connect Serial0 to a TTL to USB I get valid output so Serial0 is working UART6 is not.
Accel X: 2121 Y: 2122 Z: 2123
Mag X: 2124 Y: 2125 Z: 2126
Accel X: 2121 Y: 2122 Z: 2123
Mag X: 2124 Y: 2125 Z: 2126

Code:

void setup() {
  Serial0.begin(115200);
  delay(100);
  pinMode(13, OUTPUT);
}

void loop() {
  // Print out the data
  // Accelerometer
  Serial0.print("Accel ");
  Serial0.print("X: ");
  Serial0.print("2121");
  Serial0.print(" Y: ");
  Serial0.print("2122");
  Serial0.print(" Z: ");
  Serial0.println("2123");
   digitalWrite(13, HIGH);   // turn the LED on (HIGH is the voltage level)
  delay(1000);
  // Magnometer
  Serial0.print("Mag ");
  Serial0.print("X: ");
  Serial0.print("2124");
  Serial0.print(" Y: ");
  Serial0.print("2125");
  Serial0.print(" Z: ");
  Serial0.println("2126");
  digitalWrite(13, LOW);
  delay(1000);
}

 

waltervl - I get the same situation Uart6 does NOT receive data. It does transmit data but the receive is definitely not functional.

Andrea Rovai - Please post instructions on how you were able to get Uart 6 to receive data.

 

Original post about this problem back in March.
http://www.udoo.org/forum/threads/uart6-configuration-for-a9-access.3773/#post-17954
A patch to correct this problem was to be included in the next OS release. Unfortunately it hasn't been included in Version 2. Just finished image of new SD card with the just released Version 2 software and Uart6 still does NOT receive data.
The new release is great but ... how about a minor update of Version 2 to correct Uart6 Receive.

 

We're sorry guys that UART6 still has problem. We're focused on solving them. You'll be the first to know as soon as we have news.

 

Thanks Andrea. I really appreciate the work of you and the Udoo team.

 

Thanks Andrea! I'll wait for update. Great UDOO Team!

 

Andrea ! Pls provide updates on the patch, Is it available in new Release of Nov 17, 2016 ?