SparkFun Serial Basic Breakout - CH340G

The SparkFun Serial Basic Breakout is an easy-to-use USB-to-Serial adapter based on the CH340G IC from WCH. It works with 5V and 3.3V systems and should auto install on most operating systems without the need for additional drivers. The Serial Basic uses the CH340G IC to quickly and easily convert serial signals to USB. It’s a great lower-cost alternative to the extremely popular FTDI Basic.

The pinout of the Serial Basic mimics the common DTR/RX/TX/VCC/CTS/GND pinout found on hundreds of FTDI-to-USB derivatives. It can also be used as a general serial device for debugging (such as with a GPS module). There is a jumper on the rear of the board that controls the output voltage on the VCC pin. By default, the board outputs 3.3V and has 3.3V signals. Changing this jumper to 5V will cause the board to output 5V on the VCC pin with 5V signals.

Get Started with the Serial Basic Breakout

SparkFun Serial Basic Breakout - CH340G Product Help and Resources

Serial Basic Hookup Guide

February 9, 2017

Get connected quickly with this Serial to USB adapter.

Core Skill: Electrical Prototyping

If it requires power, you need to know how much, what all the pins do, and how to hook it up. You may need to reference datasheets, schematics, and know the ins and outs of electronics.

2 Electrical Prototyping

Skill Level: Rookie - You may be required to know a bit more about the component, such as orientation, or how to hook it up, in addition to power requirements. You will need to understand polarized components.
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Customer Comments

  • What’s up with the quarter on this one? :)

  • I don’t suppose you’ll offer a version of this CH340G breakout that includes the missing pins? I got this and didn’t realize it breaks out the DTR instead of RTS pin. I needed CTS/RTS instead of CTS/DTR.

    Made it work but the SMD chip soldering was a PITA and at one point I feared I had ripped the leg off the chip in the process.

  • How do I set the jumper to switch to 5 volts?

    • You will need to remove the blob of solder currently on the jumper (I usually double check with a multimeter or something to make sure it is fully disconnected). Then add a similar blob of solder connecting the middle pad to the 5V side. Basically the middle pad is connected to the VCC output on the board and the blob of solder is connecting that pad to either 3.3V or 5V.

  • Will this work with the Sparkfun Oscilloscope clock y'all used to sell?

  • I’m sad that you wen’t to micro USB. Every Dev board I have from sparkfun with Micro USB on it has broken off at sometime =(

    • :/ That’s a bummer to hear. We’ve changed the microB connector and footprint significantly over the last few years to improve stability. I wouldn’t design with it if I wasn’t confident in it. I’m sorry to hear you’ve had some broken units. By all means let customer service know - we will certainly replace anything defective.

      • Nate, you may already be using these “tricks”, but I’ll share them here for the benefit of readers working on their own design: First, the use of “through-hole” connectors rather than surface mount connectors will give the best protection against breaking off. Unfortunately, that’s not always possible, and does increase the manufacturing cost even when it is feasible. Second alternative is that some connectors having plastic pins that fit through holes in the board. These are easier to break off than through-hole connectors, but are better than others. The third alternative is connectors with “wings” attached to the “shell”, with the wings soldered to the board. The important thing to do is to make sure that the pads that they’re soldered to have vias to pads on the other side – this gives a measure of mechanical resistance to the pads being “pried off” when stress is applied to the connector. Making sure that the vias have no solder mask on either side can encourage some wicking of solder when they’re soldered, and gives a little additional mechanical strength.

        BTW, I’d also include the “via” trick on any surface pad meant to be soldered by hand (especially to wires or connectors). I’ve had problems with this on one of a certain other company’s product. It may have been a “production glitch” with copper adhesion problems, but vias would have likely prevented the problems I had. (FWIW, I have over a half century of experience with soldering, and have only lifted about 3 pads this millennium.)

        • Thanks for the feedback. The current microB footprint uses the little plastic pins as well as vias on the pads. Having both of these has increase reliability over the past few years, but we are still looking into making these even sturdier.

Customer Reviews

3.7 out of 5

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0 of 2 found this helpful:

Doesn't seem to work on linux

I tried to compile the linux driver on my raspberry pi:

Linux rpi 4.9.27-v7+ #997 SMP Tue May 9 19:58:37 BST 2017 armv7l GNU/Linux

Didn’t work. I googled around and it appears the driver isn’t compatible with newer 4.x kernels. I suggest you just buy a real FTDI board so you don’t have to deal with this.

it works without any driver work on 4.4.5 for me, and at 5V also

seems like some of the other sparkfun USB-Serial adapters don’t work at 5V for some production runs at least, ao at the moment I like this one best

Works as advertised

This board is working fine for me. I’ve used it on both Mac (OSX 10.11.3 El Capitan) and Windows 7. I did find it necessary to load the device driver onto both computers. The LEDs that indicate TX and/or RX traffic are a useful feature.