kgsws' mix

One my project requires mono audio and graphics LCD over WiFi. HLK-RM04 is very cheap board and can do just what i need, with some hacks :)

In this example i use simple app to stream audio over WiFi to this boad. I2S is using DMA and double buffering. Audio is generated using 8bit mono DAC, MCP4801.

SPI is semi-hardware; clock and data lines are hardware SPI, but chip select is hacked GPIO inide SPI driver. This is way faster than bitbanging. I have also included simple graphics library.

Have you ever wondered how to get 3v3 from battery, and with ability to use it while charging? Well, i have one project where i need that, so i have some solution.

MCP73871 - battery charger with power sharing; while charging, output is taken from charger, not a battery, so it won't confuse charing process

TPS63001 - integrated buck/boost converter; from input range 1v8 - 5v5 you always get 3v3

You need a hot air and soldering paste to solder these, but i think it is worth it.

Note: This board is very specific to my use, it also outputs unconverted voltage from battery/charger and it is set to charge with 1A, so no USB. You can easily alter whatever you need using datasheets.

This is my old project. Reposting so it is available here.

It's an old, not so effective way to play games from SD or MMC card. It has many limitations so it is more like proof of concept. I actually have next version WIP, but nowhere from finishing right now.

Important files here.