Hi, i’m currently building a robot using an OpenMV H7 Plus board. The robot is based on a Raspberry Pi Pico 2 board, I’m currently powering the pico through a powerbank and i’m planning on powering the OpenMV from its own VIN pin using the pico VBUS pin. I’m afraid that doing that could result in my OpenMV getting fried because the pico also powers two servo which can use a lot of power. Is it safe to power it like that or would it be safer to power it through the usb port? Can i solder an USB cable from the pico VBUS and power it from there or should i use another USB on my powerbank?
You should not power the servos from the VBUS pin output of your pico. They should have a battery bank source that is separate.
A picture would help.
I don’t have the robot on hand right now, but here is a screenshot of the PCB, the pins labeled OPEN_MV1 are for the OpenMV Power/UART, there is another UART labeled LEGO_SPIKE1 wich connects the Pico to a LEGO SPIKE hub (the pico is used as the robot “brains“ and the LEGO is used for the robot’s movements), there are also the servo terminals labeled as MG996R1 and MG90, then there are two pins which are used to connect a simple switch. You can also see two i2c interfaces which are not being currently used
Yeah, you’re going to encounter a lot of issues with that board design.
You are powering the servos from the VBUS output. You should not do that. They should be powered by a battery.
You need to add a connector from the battery that powers the robot, and then add a switching regulator to create the voltage to power the servos.
the robot is currently powered using a powerbank, it should supply something like 2/2.5 Ah max through its usb port, should i use LiPo or LiOn batteries instead? I would like to have an only battery for the pico and the servos. The LEGO part of the robot has its own battery and it works well. I fear that the motors will stall overcharging the whole circuit, Pico and OpenMV too
I’m just saying the servos need to not be powered by the pico. The pico and openmv can still be off 5V USB.