Monday 25 May 2020

CHUSBIE552 The CH552 Development board

For a few years I have been looking at different MCUs with USB capabilities in most cases there are not many sub $1 parts that fit the bill.

If you want something small and discreet that does a few USB functions there isn't much around, normally the barrier to entry on these types of MCUs 8 bit and 32 bit included is over the $2 mark. The issue start to become when costing the bill of materials $2 on the BOM becomes $8 by the time you get to retail price.

There are a few low cost MCUs out there like the range from STC or Nuvoton once you add a USB transceiver the cost seems to double.

I know it sees to be very focused cost but with companies form overseas being able to produce USB devices with the low retail price there must be some solution out there.

My over all goal is to demystify USB and develop a platform that gives developers confidence to develop USB devices without large overheads or in some cases complicated stacks that are beyond comprehension.

I have spoken about my admiration of the CH55x range from WCH that are a series of ultra low cost micro controllers with USB in some of the range is down in the $0.25 category in volume. Which is unbelievable a full capable MCU for the same as a discreet logic IC.

As well as the USB2.0 transceiver and the E8051 processing core itself they come with a resonable array of peripherals as well 2 x UART port, SPI  , 4 channel 8 bit ADC and 10k to 64k flash space in the case of the CH559.

There are a few dev boards out there for the CH55x range mainly from electrodragon with their CH55x range of boards. They are a nice range but I feel they have a couple of  points that I would love to see improved on. 

This is why I decided to start the CHUSBIE range starting with the CHUSBIE552 based on the CH552T or CH552G a lower cost less IO version.

With the CHUSBIE552 I have added onboard functions that I think will be the most useful to a developer like: 
  • onboard reset and bootloader buttons
  • RX and TX indicator LEDs
  • sensible pin-outs with pins and ports in order
  • optional landing for external XTAL crystal for precision timing applications 
  • Power indicator LED

I would like to see a general adoption of the CH55x range chips in a similar way to the ESP8266 and ESP32 (notably neither of which have native USB which in my humble option would be a killer addition).

I want to work on the software stacks to make them more friendly for a start making sure the Chinese comments are translated to English for the examples especially the USB ones. My point is that USB doesn't need to be this mystical black box that can't be easily accessed by most hobbyists and makers.

So far in my research I found firmware for USB CDC device, USB HID device and USB JTAG device all of which i am trying out to incorporate into a master repository.

Updates to this project can be found here:

I hope to have the completed board available on my Tindie store here:

No comments:

Post a Comment