Welcome new user! You can search existing questions and answers without registering, but please register to post new questions and receive answers. Note that due to large amounts of spam attempts, your first three posts will be manually moderated, so please be patient.
Because of un-manageable amounts of spam despite our use of CAPTCHAs, email authorization, and other tools, we have discontinued this forum (see the 700k+ registered users with validated email addresses at right?). Please email us any questions or post bug reports and feature requests on GitHub at https://github.com/jevois -- The content below remains available for future reference.
Welcome to JeVois Tech Zone, where you can ask questions and receive answers from other members of the community.

Hardware serial gives no module output without USB connection

0 votes

I have a microcontroller connected to the serial output of the JeVois camera. Via this serial line I can send commands to the camera and receive its response.

For the DemoArUco module, when I power up the camera, I receive the boot messages:

INFO: JeVois 1.9.0

INFO: Linux version 3.4.39

INFO: CPU: 1344MHz, 30C, load: 0.24 0.05 0.02 1/57 87

INFO: MemTotal: 238428 kB, MemFree: 170328 kB

INFO: OUT: YUYV 640x300 @ 60fps CAM: YUYV 320x240 @ 60fps MOD: JeVois:DemoSaliency C++


Then I issue a number of commands:

setpar serout None


setmapping2 YUYV 320 240 30.0 JeVois DemoArUco

setpar serialdev Hard

setpar serlog Hard

setpar serstyle Detail

setpar serout Hard


And get the response:


ERR Unsupported command [streamoff]

INF Engine::setFormatInternal: OUT: NONE 0x0 @ 0fps CAM: YUYV 320x240 @ 30fps MOD: JeVois:DemoArUco C++

INF Camera::setFormat: Camera set video format to 320x240 YUYV

INF Engine::setFormatInternal: Instantiating dynamic loader for /jevois/modules/JeVois/DemoArUco/DemoArUco.so


INF Engine::setFormatInternal: Module [DemoArUco] loaded, initialized, and ready.

ERR engine:serialdev: Provided value [Hard] rejected because Parameter is frozen




INF Camera::streamOn: 5 buffers of 153600 bytes allocated

INF Gadget::streamOn: 4 buffers of 384000 bytes allocated


INF ArUco::detectMarkers: Loaded camera calibration from /jevois/share/camera/calibration320x240.yaml

And after that I receive the correct output if an ArUco code is in view, e.g.:

D2 U17 4 -284 215 -384 205 -382 178 -281 188

This all works fine as long as i power the camera via the USB of my computer (no jevois software such as jevois-inventor is running on this computer). However, when I power the camera via a power-only USB plug (so no data connection to the computer) I get the same response to the commands, but I receive no output if an ArUco code is in view.

What do I need to do to get this working without a connection to my computer?

It seems related to the problem mentioned here, but it gives no solution.

asked Nov 28, 2018 in User questions by Jeroen (120 points)

1 Answer

0 votes
for reference, this was fied online by following this tutorial:


and putting the commands in initscript.cfg
answered Nov 29, 2018 by JeVois (46,580 points)