Undervoltage
Undervoltage
Please forgive if this not the correct place for the issue:
I bought and installed the 5V stepdown switching.
Power is supplied by two 18650 cells in series, charged.
The Raspberry is not directly wired to anything other than being in the same chassis as the motors, the Roboclaw, the wiring, and sharing common ground.
Everything is powered but motors are not running.
The one external connection in addition to power and ground is from a USB port to the micro USB on the Roboclaw, but it is through an USB opto-isolator.
When I connect the isolator to the Raspberry, the "dmesg" facility starts to complain about "under-voltage".
I had had the Raspberry overclocked, so put it back to default.
The situation did improve. However it still complains at least once when the opto-isolator is connected.
Just wanted to know if you've encountered / heard about this.
thank you.
I bought and installed the 5V stepdown switching.
Power is supplied by two 18650 cells in series, charged.
The Raspberry is not directly wired to anything other than being in the same chassis as the motors, the Roboclaw, the wiring, and sharing common ground.
Everything is powered but motors are not running.
The one external connection in addition to power and ground is from a USB port to the micro USB on the Roboclaw, but it is through an USB opto-isolator.
When I connect the isolator to the Raspberry, the "dmesg" facility starts to complain about "under-voltage".
I had had the Raspberry overclocked, so put it back to default.
The situation did improve. However it still complains at least once when the opto-isolator is connected.
Just wanted to know if you've encountered / heard about this.
thank you.
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Basicmicro Support
- Posts: 1594
- Joined: Thu Feb 26, 2015 9:45 pm
Re: Undervoltage
It sounds like your USB opto-isolator is pulling to much current from the RPi USB port. Or your RPi power source is dipping below the RPi waring limit. The RPi in my oppinion is too sensitive to the 5v input reading but you want to make sure it isnt too low or you may have trouble when writting to your SD card(eg corrupted SD cards).
Re: Undervoltage
Hi, thanks.... I neglected to update this topic...
correct, the 5V was low. I at first thought it was the 5V stepdown regulators I had bought... but after more testing / tweaking / eliminating -- I ended up removing connectors and doing straight soldering.
I think that was it. working now.
correct, the 5V was low. I at first thought it was the 5V stepdown regulators I had bought... but after more testing / tweaking / eliminating -- I ended up removing connectors and doing straight soldering.
I think that was it. working now.