USB to UART Solution: Which is Better?

September 25, 2020

USB-to-UART-Solution-Which-is-Better
There's many popular USB to UART solutions, FT232, CP2104, CH340, or PL2303, which is better? Some suggestions for choosing a USB to Serial converter.

Here is a very detailed& professional analysis of the FT232 fake IC: https://zeptobars.com/en/read/FTDI-FT232RL-real-vs-fake-supereal

Makerfabs encountered the same problem some years ago, that the FT232 stopped work as the windows driver updates… After that, we purchase all our FT232 IC only from mouser, to ensure they are the original brand, which is expensive (>$3) but not lead to us further troubles.

But by now, we have some better choices than the FT232:

1. CP2102/ CP2104

This is my preferred solution. All Makefabs IoT boards use this solution. The price less than $1, this is what we suggest.

The datasheet at https://www.silabs.com/documents/public/data-sheets/CP2102-9.pdf

2. CH340G/ CH340C

There plenty of Chinese-made Uno boards with CH340G IC, this chip really cheap, but not so stable. As MF experience, the CH340G has strict requests on the load capacitance, that 20% not works in every production …bad…

Lucky is that the new generation of CH340C released, this CH340C with internal oscillator, works much better.

The datasheet at https://www.mpja.com/download/35227cpdata.pdf

3. PL2303

Also a cheap choice, very cheap.

Datasheet: http://www.prolific.com.tw/UserFiles/files/ds_pl2303HXD_v1_4_4.pdf.
Ref board: https://www.amazon.com/Prolific-PL2303-USB-TTL-Module/dp/B008958S7A.

4. Atmega16U2

This is the official Arduino solution. Arduino uses a programmed 16U2 to act as a USB2UART convertor but not FTR232, it should be because the 16U2 is much cheaper than the FT232 solution, but by now, there so much other cheaper solutions, this solution not popular, at least we do not have even 1 customer using this solution, in the past 3 years.

5. Summary

With more than 6 year's hardware engineering experiences, Makerfabs suggest:
1. Solution_1 CP2102/ CP2104
2. Solution_2 CH340C

Because the PL2303 not stable& popular, and the Atmega16U2, I do not know, anyway, it is not so cost-effective.

6. CP2104 USB to Serial Converter

Also, if you have purchased Makerfabs Maduino boards or Lora boards, we suggest CP2104 USB to Serial Converter for programming. It's super tiny and cheap, only $3.5, also very easy to use, you can plug in directly into Makerfabs products to programming. Below are Makerfabs the Lora soil moisture sensor and the 30A Lora relay, super easy and convenient with CP2104 USB2UART programmer.

Here are some details about Makerfabs CP2104 USB to Serial Converter:

This CP2104 USB to Serial Converter is super tiny, a highly-integrated USB-to-UART Bridge Controller providing a simple solution for updating and programming.

6.1 Features:

There huge kind of USB to Serial converters on the market, while we Makerfabs design this module specially:
1. 3.3V/5V compatible, with a switch on the boards, to select;
2. DTR pins available, which is essential for Arduino auto-programming;
3. Super tiny, with a micro USB connector.

With this easy/cheap module, it would be the most ever easy for communication between your PC with Arduino, both for serial port communication of Arduino auto-programming, such as the Lora moisture sensor and Lora 30A relay.

6.2 Pins Arrangement:

● Pin1-------DTR (Connect to Arduino Reset)
● Pin2-------RXD (Connect to Arduino TX)
● Pin3-------TXD (Connect to Arduino RX)
● Pin4-------GND
● Pin5-------VIO (5V or 3.3V)

If you have more USB to UART solutions, or need custom PCBA service, pls contact service@makerfabs.com.

USB to UART Solution: Which is Better?