Everyone needs a projects review at sometime. Let us help each other with it. Schematic / Layout / C / C++
This has all the bells and whistles, so it'd be nice to get some more eyes on it.
It's exported from Upverter, which to be honest, I'm not particularly happy with the exported schematic view. The schematic looks decent within the tool, but as you can see, it's kinda terrible when viewed here!
Other than that, I quite like Upverter.
It's an ESP8266 dev board.
USB-UART bridge uses DTR and RTS to control the programming pins, NodeMCU-style.
Battery or USB, whichever is higher, feed the main voltage input. That goes to a SMPS, which a fixed 3.3v output, and an enable pin tied to a low-voltage cut-off for when the battery sags to around 2.8v.
USB power is also feeding a battery charger.
Most of the semiconductors are also ones that are available through AliExpress, which to me, means the Chinese clone market is using them and they should remain cheap/good/available, and easy to scale up if I want to manufacture.
(Excuse the terrible soldering, it was bodged a whole bunch of times as I was adding and taking things out of the circuit)
Most of the board works really well! USB enumerates and can program, the battery charges and works, the ESP8266 works.
A few issues that I missed, and need to be corrected: