References about Sipeed and Kendryte K210:
ArduinoCore-k210
kendryte-standalone-sdk
Sipeed documents
kendryte-standalone-demo
many demo programs that can be adapted
https://github.com/sipeed
Sipeed's main github
http://dl.sipeed.com/MAIX/HDK/Maix-Bit/Maix-Bit%20V2.0(with%20MEMS%20microphone)
schematic of your board
Some-Sipeed-MAIX-GO-k210-stuff
kendryte_standalone_programming_guide_20190311144158_en
all the information about programming peripherals on the K210 processor
Train, Convert, Run MobileNet on Sipeed MaixPy and MaixDuino !