TL;DR: I need a technical check on my circuit design that utilizes LiPo battery & USB-C charging.
Hi everyone! I couldn’t find a sub-category in the forum that fit my post so I just put it under general electronics.
I’ve been working on a project to build my own camera slider. It’s powered by Sparkfun Pro Micro and A4988 Stepper Driver Modules. Right now, I’m using only one stepper motor but I do want to have the option to have two more stepper motors for more degrees of movements in the slider. Each motor is rated at 12V and 0.4A/phase.
I’m designing the PCB (on EasyEDA) and I have a few constraints in terms of how it will be powered; either through a USB-C connector or the LiPo battery. The battery itself can also be recharged by the USB-C port. As for the power through the USB-C port, I’m going with the standard 15W option (5V & 3A) so I don’t have to deal with the whole USB-PD circuitry BS that comes with it. There is a switch that will turn on the Arduino & motors from either the battery or USB-C power source. When the switch is off, the battery can still be recharged if the USB-C is plugged in.
For the components, I’m thinking of choosing this battery from Adafruit as it should provide enough power for now. I also found this YouTube video from Electronoobs on battery charging and boost converting so I followed along for my circuit design. I mixed and matched to try to fit my need. I’ve attached a screenshoot of the circuit that involves the power management. Note that the “C” and “NO” nets are the common and normally-open pins of the power switch. The diode “D2” is to force the anode (+ side) to flow the positive/conventional current from the battery to the boost converter and not back into the TP4056 recharging IC. Diode “D1” is to prevent the 5V current from the USB-C Vbus to flow to the anode of the battery which is 3.7V.
If you see any potential problems with my design or got some questions, please comment on it. I want to make the PCB design using this circuit ASAP so I can get it made. I’m still very new to this area of circuitry. Thanks!