Should both the barrel jack power supply and the USB cable always be connected to the device? It seems like when I use the barrel jack supply the camera sometimes gets significantly hotter, which sort of makes sense, but I also saw a brief puff of smoke the first time I connected them both to the camera. That makes me think something is wrong although the camera still works when connected to my PC. Are there any suggestions for when not to use the barrel jack, or if it always should be used then does the barrel jack need to be connected before the usb connector?
OAK-D usb power vs barrel jack supply
Hello jpfs , in most cases powering via barrel jack isn't needed, see documentation here. I would be very interested about this smoke, if you could reproduce and make a video that would be perfect. Also it shouldn't be any hotter, as it doesn't go into "power saving mode" when power supply can't keep up - it simply shuts off.
Thanks, Erik
I may be confusing my memory between the Oak-D and the Oak-D-IoT-40 regarding which one "smoked" because I have one of each ... I think it actually was the IoT device, and it only happened once the first time I connected both cables. I think I connected the barrel jack first. After the puff of smoke, there was a "burned semiconductor" smell, and I am guessing that there could be a diode between the barrel jack input and the USB input that shorted. I have not looked at the schematic, though to confirm this.
I can try to recreate the issue but I think that whatever happened was a 1-time thing since I am pretty sure some component (diode?) was permanently damaged.
However, the Oak-D is the device that sometimes gets noticeably hotter than other times. I can try to look for a correlation between usage and heat, and if I can discern one I will post an update.
jpfs did you power the device with 5V power supply? There has been a few cases where people plugged in 9V power supply to the power jack and it burnt the protection diode - which fits your description as well. And you are right, some functions (eg. video encoding, AI inferencing...) add quite a lot of computation/heat.
2 months later
Hi, I just got my OAK-D device and have it connected to the USB port of a Raspberry Pi. You DO need to have the barrel jack plugged in that configuration otherwise you get the following error: Segmentation fault (Address not mapped to object [0x20d]. So it looks like there isn't enough power coming from the Raspberry Pi. Once I plug the barrel jack in everything works well. I have the Pi connected to the barrel jack through a power supply so the Pi is getting sufficient power. I was hoping to run the OAK-D on a robot. Any suggestions on how to power it in that scenario? Thank you.
Hello mjwhite2529,
In most cases, RPi can supply enough power (it can supply max 1.2A, and OAK cameras consume up to 5W), but if you have other devices connected to the USB ports they will draw power as well.
WRT startup, I believe RPi OS has some options to run python scripts on startup, eg. tutorial here (I haven't test it).
Thanks, Erik
Hi Eric,
My OAK-D device definitely does not work without the power barrel jack plugged in. I get the message:
[2022-04-13 14:21:55.390] [warning] OpenVINO 2021.3 is deprecated!
Stack trace (most recent call last):
#Segmentation fault (Address not mapped to object [0x20d])
Segmentation fault
If I plug in the barrel jack everything works fine. Do you think I have a faulty device?
Hello mjwhite2529 ,
It doesn't sound like a faulty OAK device, as it's working as expected when supplied with enough power.
Thanks, Erik