CH340G USB to RS232 TTL module schematic (D-SUN-V3.0)

Cheap ($1) chinese USB to RS232 TTL modules from eBay. Works fine and is cheap enough to be thrown anywhere.
Windows drivers download: http://www.arduined.eu/ch340g-converter-windows-7-driver-download/
CH340G datasheet (third-party translation): http://cdn2.boxtec.ch/pub/diverse/ch340g-datasheet.pdf

Schematic (reverse engineered):

CH340G D-SUN-V3.0 module schematic

CH340G D-SUN-V3.0 module schematic


Source version (KiCad): https://github.com/NiceCircuits/modules_from_china/tree/master/CH340G_D-SUN-V3.0

PCB with marked components:

CH340G D-SUN-V3.0 module PCB with marked components

CH340G D-SUN-V3.0 module PCB with marked components


Other photos:

2 Responses

  1. Andy Hull says:

    If you find you are having issues programing a device that requires 3v3, usin one of these CH340G boards, try a 10k pull down resistor to gnd on the TxD pin. This will lower the TxD voltage from 3v6 to nearer 3v2, which is more likely to work with for example an ESP-8266, which is very sensitive to over voltage.

  2. Mike Page says:

    After purchasing one of these over ebay, I have been trying for a week to bild a programming cable for my Baofeng UV-5R tranciever to no avail. I hade no drivers issued with the little module so windows xp or linux does not see the device. At least you could put a link on your homepage that points to the driver. I still have no resolve to my problem.

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