Sonntag, 23. August 2015

ESP8266 in the wild, WiFi LED controller hack.

Recently I found a cheap (9€) WiFi LED controller on AliExpress:

I bought 2 because I was curious if it would be possible to hack this drivers.

Controller overview:

This pictures show the PCB. As you can see there are pins labeled as RX,TX,GND,3.3V. I simply connected an USB-Serial converter to the pins. The two other pins are GND and GPIO0. If you set a jumper between this two pins, the controller starts in bootloader mode. 

The chip above is a NXP HC245, a 3-state Octal bus transceiver. It is used to drive the N-channel MOSFETS (20N06L - 20 A, 60 V, N−Channel DPAK).

The power supply is a 2 stage design. A AOZ1212 3A Simple Buck Regulator to convert the input voltage to about 5V and an AMS1117 low dropout voltage regulator to get 3.3V.

The pinout for the ESP8266 is as follow (Arduino numbering)
redPIN    12
greenPIN  13
bluePIN   15

// W FET
w1PIN     14
w2PIN     4

// onbaord green LED D1
// onbaord red LED D2

TX GPIO2 @Serial1 (Serial ONE)
RX GPIO3 @Serial

Jumper closed -> start in bootloader mode on Power on.
Jumper open   -> start user program 
I have a simple demo sketch on github:

This can be controlled with openHAB.

You should also take a look at my other ESP8266 project: