Replacing CH340C with CP2104
If you would like to replace the CH340C on your Badgy with the CP2104, we've designed an adapter PCB for it:
You can remove the display by first disconnecting the ribbon cable from the connector, and slowly twisting/rotating the display to detach it from the sticky tape. Alternatively, use a sharp knife to remove the sticky tape by slicing it from under the display. Do not pull the display to remove it! The sticky tape is very strong and you will crack the display glass!
To remove the CH340C, it is best to use a heat gun to reflow (300-350C) the chip and lift it up with tweezers. Make sure the solder on the pins and pads have completely melted (i.e. shimmering) and you are able to easily move the chip around. You don't want to use any force to pull the chip up, or else you might damage the pads by lifting them up too. Be careful not to move any of the other components during this time, and remember, the board is hot!
You'll want to align the adapter board exactly to the pads on Badgy. Note the orientation of the board; the marking on the CP2104 should be pointing down. Once you have aligned the board, use your heatgun again or a soldering iron to reflow the solder; the left over solder on the pads may be sufficient, but if not then feel free to add some more solder for a good connection. The important pads are labeled with their pin function in the image above, all other pads are not used.
- I am unable to detect the CP2104 on my computer
- Try realigning the board and check to make sure every pad has a good solder joint to the adapter board
- I can detect the CP2104 as a serial port, but I am unable to flash/upload firmware
- This is likely caused by the boot sequence not properly initializing (i.e. GPIO0 not pulled low during reset). Check the DTR and RTS connections again (refer to the diagram above) as these pins drive the boot sequence to enable flash mode. Also make sure the blue LED on the ESP-12F module is blinking, if not, then check the TX and RX pads again