I hope someone can help. I’ve a little project using my Photon to driver a stepper motor via a TB6600 stepper motor driver. Whilst the photon was powered from the PC USB port and the Stepper via an 18V 5A PSU everything worked great. I then wanted to use the single PSU to driver both the Stepper and the Photon. When I stepped the voltage down to the Photon (via multiple methods, which I’ll explain) the stepper motor no longer ran smoothly. I’m using the AccelStepper library and it just kept stopping and restarting as it tried to move.
I have tried:
- Using an LM2596 3A adjustable step down DC-DC board with the voltage output adjusted to 5-5.2V
- Using an XL4014 5A adjustable step down DC-DC board with the voltage ouput adjusted to 5-5.2V
- Using either of the boards above set with a higher output voltage and fed in to a small LM7805 Voltage regulator with input and output capcitors, which resulted in an output voltage of 4.95V
With the voltage feeding into Vin on the Photon, all resulted in the same outcome, steppers not running correctly.
I checked powering the Photon via a small mains powered USB PSU and that worked fine.
I then purchased an Amazon Basics 12-24V Micro USB Car Charger. I fed the 18V into the input of the car charger and connected the MicroUSB to the Photon and it worked.
My conclusion thus far is that there is something odd going on when powering via Vin instead of the USB connection, but I don’t know what.
Whilst I can temporarily cannibalise the Car Charger PSU, the way I planned to mount the Photon in it’s enclosure it’s practical to be able to connect to the USB connection.