The freescale S08JS series is one of the lowest cost microcontrollers with a hardware USB implementation. The availability of free C development tools (SDCC and Codewarrior) make the S08JS a great candidate to develop all sorts of inexpensive USB gadgets. microJS is a fully functional S08JS minimal system on a PCB less than a square inch. The board headers can be plugged into a breadboard for prototyping or soldered to another PCB for a permanent placement.
Freescale DEMOJS demo board is a great tool for evaluating the features of the S08JS MCU. However its price (~80USD) is too high for the average starving hacker like the members of our staff. Inspired by ultra low cost development systems from other vendors we developed microjs.
- support S08JS8 and S08JS16 in SO-20W package
- micro USB connector
- crystal oscillator for full speed USB operation
- BDM connector (for programming/debugging)
- 2 LEDs (1 power, 1 controlled by PTB3)
- All port pins (except PTB2/BKGD) are routed to the side headers
- option to connect PTB2/BKGD to the side headers
- option to connect PTA6/RxD, PTA7/TxD and PTB1_RST to the BDM header