#CH341SER USB DRIVER FAIL SERIAL#

Otherwise the device will be recognized as a standard USB to serial converter. That's why you should put a jumper across pins 1 and 2 of the UART connector. Note that the device works as a programmer only if ACT# pin is connected to ground via a resistor. User johnmx from EEVblog Forum has succeeded in converting this programmer to 3.3V levels. You will also need to connect V3 pin (9) to VCC (3.3V). In order to turn this programmer into a 3.3V device, you could cut the 5V line from VCC pin (28) and tie it to the 3.3V output from regulator. For improved reliability and to avoid burning memory chips, I highly recommend using a level shifter. There is none on this board.Īnyway, I used the device with I2C EEPROMS (3.3V and 5V) compatible and also SPI FLASH memories (3.3V devices) without any issues. I don't know why the designer even used a regulator, if it didn't provide a switch to choose between 3.3V or 5V levels and supply.īy reading the datasheet, we can see that the manufacturer recommended to connect a 0.47 uF capacitor between RSTI (pin 2) and VCC for improved stability. And this seems to be the only function of the 3.3V regulator (besides the 3.3V pin on the SPI connector). The problem is that any memory you fit in the socket will be powered from 3.3V. The chip is powered from 5V, so its I/O ports will also use 5V. Now, let's return to the schematic and analyze it a bit. Their product page offered a the PCB design of the device (only top side, however).ĬH341A Mini Programmer PCB (by WAVGAT/AliExpress) I also found WAVGAT store (a seller on AliExpress).

Schematic of the black CH341A Mini Programmer The schematic is quite simple, based on datasheet. I took the multimeter and started to trace lines on the programmer PCB until I got a complete schematic. It didn't have the pinheaders on the sides of the ZIF socket which I wanted to know what they are for. SchematicĪfter some searching I found a schematic of a CH341A based programmer, but it wasn't exactly right and complete. The programmer can be bought with additional sockets and adapters, some of them with voltage shifting circuits. Photo of the black CH341A Mini ProgrammerĪ quick look at the board reveals the main electronic parts used: CH341A, a 12 MHz crystal required by the chip, a 3.3V regulator, two 7 pin headers and the ZIF ( zero insertion force) socket. But, first of all, let's have a look at the hardware. There are open source applications that support this programmer.

Also, some source codes are available from manufacturer.

#CH341SER USB DRIVER FAIL DRIVERS#

Drivers are available from manufacturer's website (but the site is written in Chinese). The problem with these devices is that you get them without any documentation or software. A popular device is the black CH341A MiniProgrammer that you can buy for 2 to 5 USD. The IC is somehow limited in this configuration, because the programmer makes use only of the SPI and I 2C interface and leaves a lot of pins unconnected. CH341A is used by some cheap memory programmers. The chip is manufactured by Chinese company Jiangsu QinHeng Ltd. An overview of CH341A devices with driver and tools download linksĬH341A is an USB interface chip that can emulate UART communication, standard parallel port, memory parallel port and synchronous serial (I2C, SPI).

#CH341SER USB DRIVER FAIL HOW TO#

'Setup.Take a look at the schematic of this versatile programmer to learn how to use it properly.

Ch341ser usb driver fail