Aaron Christophel's TI CC8051 Flasher Makes It Easy to Repurpose ePaper Price Tags with an ESP32

Developer Aaron Christophel has put together a tool, which turns an Espressif ESP32 microcontroller into a flasher for the non-volatile storage on selected Texas Instruments CC8051-based microcontroller parts.

"My personal goal is to reflash microcontrollers used in ePaper price tags like this 2.9-inch version, which uses a CC1110 internally," Christophel explains. "Normally you would use a CC debugger which comes directly from Texas Instruments but costs around €10 [around $11) and if you just want to reflash some cc microcontroller to act as an access point or just to have a different firmware on it […] you now can very simply just use the ESP which most likely most of you will have already laying around."

The project supports the Texas Instruments CC1110, CC2430 up to 64kB, the CC2431 up to 64kB, the CC2510, and CC2511; additional chip support may be added in the future, while the open source nature of the project makes it possible for others contribute towards broader compatibility.

To carry out a flashing operation, the host ESP32 needs to be connected to the target TI chip on just three pins plus 3V3 and ground; manual wiring is possible as a one-off, while a custom circuit board makes wiring easier. Many CC-based circuit designs include debug headers, onto which the custom board simply slots; those that don't typically expose the required pins as test pads requiring manual soldering.

On the software side, the ESP32 itself hosts a web page that acts as the user interface — accessible in-browser over the ESP32's Wi-Fi radio. The UI allows for binary files to be uploaded for flashing, and also for existing flash memory contents to be read out and downloaded.

A video demo of the project is available on Christophel's YouTube channel, with full source code available on GitHub under the reciprocal GNU General Public License 3.