#780 AT89C2051 Breadboard Adapter
Wiring up the reset and oscillator support circuits gets a little tired each time one wants to prototype an AT89C2051(8051/MCS-51) project. I made a little breadboard-compatible module that let’s me easily pop the microprocessor in and out, and just requires a power and ground connection on the breadboard.
Notes
I’ve been doing a few projects using the 20-pin AT89C2051, 8051/MCS-51 compatible chip. To run, it requires:
- an external oscillator - I’m using 16 MHz with loading capacitors
- the RST pin to be pulled low with an RC circuit. The AT89C2051 data sheet actually specifies a RST pull-down of 50kΩ-300kΩ, but it seems important to also couple to VCC with a capacitor of 2.2µF or more.
Rather than need all this external support circuitry to be setup on a breadboard when prototyping, I decided to load it all on a breadboard-compatible board with a ZIF socket to allow the microprocessor to be easily popped in and out.
Circuit Design
The minimal support circuitry:
Protoboard Design
Sketching out a compact design:
Testing the Board
Running the Blinky program:
