For a project in school I have to build a robot playing a bass guitar.
To play the notes I planned to plug 16 servos to Adafruit's PCA9685 but it doesn't supply enough Amps to the servos. How can I power the servo motors externelly but still controll them via the PCA9685? I know that I don't have enough amps because the PCA9685 is able to controll much weaker servos, but these aren't powerful enough. Can anyone help?
I use the Raspberry Pi 3 model B+ to control everything and several BMS-410C as my servo motors.
Best Answer
Looking at the application notes The logic on the PCA9685 should be powered from the same supply as the Raspberry Pi (3 - 5V) Vcc and this is low power. The servos can have their own separate supply V+ which can be as high as 12V if required. This can typically be a 5V 10A PSU and is connected to the PCA9685 via its V+ own connection block.
Each of your 3 wire servos has a control pin, a power supply pin for V+ and a common ground. They do not have to be powered from the same supply as the logic. Therefore all you need is a separate PSU with sufficient capacity to power your servos under full load.