Doing it wrong


I have noticed a few times when I hot plug in an I2C sensor, sometimes it makes the RasPi reboot. It only happens for some sensors, not all of them. Typically accelerometers, OLEDs and LCDs.

Just wondering if anyone can explain what is happening. Is the sensor trying to draw too much power and the Pi panics and reboots?

Am I going to break my GrovePi / RasPi if I keep doing this cowboy hot plugging?

Hey Mike,
The reboot is because of the modules suddenly drawing a large amount of current as soon as they are powered and the voltage on the 5V line drops below 4.75V.

You shouldn’t break your Pi with this. It is similar to turning off the power without properly shutting down the Pi. One thing that you can try is keeping the 5V line at 5.25V, so the drop is still tolerable. A lot of adafruit powersupplies come at 5.25V.


Thanks for the quick reply!

Speaking of doing silly things…

I now have a GrovePi+ and a GrovePi!

If I configured the old GrovePi to listen on 0x06 or another I2C address, do you think I’d be able to stack both on my RasPi at once?

Is there anything special about the GrovePi using 0x04?

Hey Mike,
Nothing special about 0x04 and you should be able to get two GrovePi’s to work with the other one at another address. We had tried it long back and it did work. Do let us know how it goes.

Try not to use 0x08 because we use it for GoPiGo.