I just found an issue using vcgencmd node module if using at the same time raspivid (or any kind of access to the camera; I had the same problem with mjpg_streamer).
So if you launch raspivid in a terminal with such command:
raspivid -o video.h264 -t 0
and in another terminal I launch nodejs with only loading vcgencmd module:
npm install vcgencmd
node
var vcgencmd = require('vcgencmd');
If I list the processes in a third terminal via:
ps aux | grep vcgencmd
I found a growing list of processes: vcgencmd measure_volts core
I tried to have a look to vcgencmd source code but I couldn't find the issue. I suppose that the concurrent access of the camera and the vcgencmd. If I try to do this (access to camera and use of the regular vcgencmd), I've got a blocking access with:
vchi_msg_dequeue -> -1(22)
But I don't have any error with node-vcgencmd (and it tokk me a long time to find the reason of the issue ;)
Stéphane
I use a Raspberry Pi 2, using jessie and the lastest upgrade of the firmware.
loyd
commented
8 years ago
Hi,
I just found an issue using vcgencmd node module if using at the same time raspivid (or any kind of access to the camera; I had the same problem with mjpg_streamer). So if you launch raspivid in a terminal with such command: raspivid -o video.h264 -t 0 and in another terminal I launch nodejs with only loading vcgencmd module: npm install vcgencmd node
If I list the processes in a third terminal via: ps aux | grep vcgencmd I found a growing list of processes: vcgencmd measure_volts core
I tried to have a look to vcgencmd source code but I couldn't find the issue. I suppose that the concurrent access of the camera and the vcgencmd. If I try to do this (access to camera and use of the regular vcgencmd), I've got a blocking access with: vchi_msg_dequeue -> -1(22)
But I don't have any error with node-vcgencmd (and it tokk me a long time to find the reason of the issue ;)
Stéphane
I use a Raspberry Pi 2, using jessie and the lastest upgrade of the firmware.
Stéphane