ModalAI Forum

Hi,

I have an external sensor (a lidar) connected by UART to J3 on VOXL2 via a M0125 breakout. I am reading successfully on "/dev/ttyHS1". However I am seeing a lot of buffering in the output. If I read in a fast loop (1000Hz) I am seeing data returned in 2048 bytes lumps every 114 ms. This is a problem as the lidar is outputing frames at 10 Hz so data being returned from the UART in bigger packets every 114ms introduces some deplay.

Q. Is this expected?
Q. Are there any settings I can use to make the data return in more frequent smaller lumps?

I open the file as follows

  fd = open("/dev/ttyHS1", O_RDWR);

  tcgetattr(fd_, &term);
  cfmakeraw(&term);
  cfsetispeed(&term, B230400);

  // term.c_cflag &= ~CRTSCTS; // hw flow conrol off
  // term.c_iflag &= ~(IXON | IXOFF | IXANY);  // Turn off s/w flow ctrl

  term.c_cc[VTIME] = 0;
  term.c_cc[VMIN] = 0;
  tcsetattr(fd, TCSANOW, &term);

  tcflush(fd, TCIFLUSH);

I also tried fd = open("/dev/ttyHS1", O_RDONLY|O_NOCTTY|O_NONBLOCK); various extra args and turning off flow control with no change.

Any ideas appreciated.
Thanks

Hi,

I tried to flash the voxl2_platform_0.9.tar.gz platform release onto a VOXL2. This failed and device was no longer visible with adb devices, even after resets of device and restarting adb. I followed https://docs.modalai.com/voxl2-qdl/ instructions to recover the device using QDL. Installing the QDL image succeeded.

However multiple attempts to reinstall the voxl platform release failed (including when forcing fastboot). I varied usb cable used; deploying from Mac vs Ubuntu; forcing fastboot; re-imaging the QDL image. Ultimately I was able to redeploy (retrying the forcing fastboot instructions, using an Ubuntu machine) but I am concerned that many attempts failed.

Below are the various errors I saw. Please can you give an indication of possible causes for them so I try to avoid in future? Any help much appreciated.

1) Failure to boot to fastmode:

./install.sh   
[INFO] adb installed
[INFO] fastboot installed
----Starting System Image Flash----
Detected OS: Linux

Installer Version: 0.8
Image Version:     1.4.1
[INFO] Found adb device, rebooting to fastboot
[ERROR] Failed to reboot to fastboot
[INFO] Failed to put device in fastboot mode, exiting

Do you know what causes this?

2) Unable to write to partition

Multiple times I saw

voxl2-platform % ./install.sh
[INFO] adb installed
[INFO] fastboot installed
----Starting System Image Flash----
Detected OS: OSX

Installer Version: 0.8
Image Version:     1.4.1
[INFO] Found adb device, rebooting to fastboot
[INFO] Found fastboot device
[WARNING] This system image flash is intended only for the following
          platform: VOXL2 (m0054) 

          Make sure that the device that will be flashed is correct.
          Flashing a device with an incorrect system image will lead
          the device to be stuck in fastboot.

Would you like to continue with the VOXL2 (m0054) system image flash?
1) Yes
2) No
#? 1
[INFO] {system::0xD3B5D7000} partition returned size {0x1A435F3000}, expected {0xD3B5D7000}
[WARNING] Partition layout was found to be incorrect, this requires
          flashing the full partition table. Flashing the partition
          table will also flash every partition causing all data on
          the device to be lost.

When doing a full flash, make sure to backup any important files

Would you like to continue with the full wipe/flash now?
1) Yes
2) No
#? 1
[INFO] Found all required files


[ERROR] Failed to flash partition: partition:0

Sending 'partition:0' (0 KB)                       OKAY [  0.006s]
Writing 'partition:0'                              FAILED (remote: 'Error Updating partition Table
')
fastboot: error: Command failed

3) Low power warning

On one instance I saw the following. We were using the power supply that came with dev kit though with a US->UK adapter.

...

[ERROR] Failed to flash partition: partition:0

target reported max download size of 805306368 bytes
sending 'partition:0' (44 KB)...
OKAY [  0.007s]
writing 'partition:0'...
FAILED (remote: Warning: battery's capacity is very low
)
finished. total time: 0.020s