Rustic Engineering

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Archive for December 2009

USB Small Peripheral Board (aka PIC18F14K50 Board)

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Recently I’ve working with the little but smart PIC18F14K50 (or your low voltage version, PIC18LF14K50). These chips are cheap (about $2,5 at Mouser) and have low pin count, but very impressive specs:

  • USB V2.0 (low and high speed);
  • NanoWatt feature (sleep with 24nA!);
  • 10-bit A/D converters with auto-acquisition;
  • PWM;
  • Several Internal Clock modes;
  • EUSART;
  • 16KB Program Flash Memory;
  • 768B SRAM;

They help me with USB development. The low pin count don’t became a problem because most of times, my projects don’t use all them (in case os PIC18F4550 or PIC18F2550).

I think that it’s a good choice to design some little USB devices, like:

  • A USB accelerometer;
  • A USB thermometer;
  • A USB logger;
  • A USB GPS;

The possibilities are awesome!

Microchip develops a kit, called “Low Pin Count USB Development Kit” to present this chip. But the Microchip kit have dimensions, don’t very suitable to work like a real USB peripheral.

So I design a little board, with minimum parts to make it work. The board is a first prototype, a experiment. If works, I’ll improve it with more polish design and features, and design one with PIC18LF14K50 for 3.3v native support  and etc.

You can see the circuit and board below:


Written by forrequi

December 23, 2009 at 03:16

Posted in electronic, pcb, projects, USB

Tagged with