Hi all,I am a engineer and I come form China.
Now,I will teach you how to DIY a wireless mechanical keyboard.
sorry my bad English :(
Step 1: Buy a Used Mechanical Keyboard and a Logitech Wireless Keyboard
First, I spent about 20$ to buy a used mechanical keyboard form Alibaba,It's make up of Cherry switch, and then, I spent about 5$ to buy a used Logitech wireless.
Step 2: Dismantle Keyboard and Clear Keyboard
I dismantled the keyboard and clear it because used keyboard is so dirty.It's very important that you must use the hot wind to blow dry the key board.
And then,I cut off the routes of every key on keyboard PCB and remove the diode.
Step 3: Dismantle the Logitech Wireless Keyboard
And then I dismantle the Logitech wireless keyboard,because of I want to get a Logitech wireless keyboard control board.
I spent few days to test the relation of key and wireless keyboard control board.
Step 4: Add Background Light and Connect the Key to Logitech Keyboard Control
I spend $2 to buy about 104 LEDs form Taobao.com,and welded 330 Ohm resistance to keyboard PCB background light circuit.
I remove the mechanical keyboard MCU and connect the key to Logitech keyboard control board,when I push some key,the Logitech keyboard control board will send this key value to PC by 2.4GHz.
Step 5: Add Li-battery and Battery Charge Circuit
I find a Li-battery on my old mobile phone,so I add this battery and battery charge circuit to my keyboard,it's can be charge by MicroUSB.battery charge circuit is make by TP4067,TP4067 is a Li-battery charge IC,500mA charge circuit.
Step 6: Add STM8 MCU to Control Background Light and Check Battery Voltage
In order to control the keyboard background light and check the quantity of Li-battery,I use the STM8F003 TIMER2_CH2 to output a PWM wave to control LED brightness,and use the ADC to sample the Li-battery voltage,if battery voltage drop down to 3.5V,it's means low battery,Low Battery LED will be flash every 3 secounds.
because of the K230 keboard don't have the Print key ,Scoll Lock key,and Break key,so I connet this key to STM8,I use the Scoll Lock key to adjust keyboard background light,and the Break key to open or close the keyboard background light.
if the battery dorp down to 3.3V,the keyboard background light will be force close.
if I connet the MicroUSB to keyboard charge port,the charge LED will be turn on when battrey is charging and will be turn off if battery is full.
I spent $4 to buy a new keycap to replace old keycap.
Step 7: Finish!
When I push the Break key,the STM8 MCU will turn on the keyboard background light,and I push the Scoll Lock key,the brightness will be adjust form 1% to 100, 100% to 1%,if I release the Scoll Lock key, the brightness will be lock.
it's STM8 source code,and project development on IAR Embedded Workbench.
sorry for my bad English so much!