PS2

Table of Contents

  1. Overview
  2. Feautures
  3. Circuits
  4. Projects
  5. Library
  6. Test program
  7. How to use it?
  8. PS2Keyboard class
  9. PS2Mouse class
  10. References
  11. Limits

Overview

PS/2 device is a legacy human interface device.

It's easy to use for input device on micro controller.

http://mbed.org/media/uploads/shintamainjp/_scaled_dsc03063.jpg

http://mbed.org/media/uploads/shintamainjp/_scaled_dsc03413.jpg

So I decided to design the library.

The library use only 2 pins (CLK and DAT).

It use interrupt based receive, so your application codes will simplify.

Feautures

  • Supported a PS/2 keyboard and a mouse.
  • Interrupt based receiver.
  • Simple interfaces.

Circuits

Circuits

Projects

Library

Test program

How to use it?

PS2Keyboard class

#include "mbed.h"
#include "PS2Keyboard.h"

PS2Keyboard ps2kb(p12, p11); // CLK, DAT

int main() {
    PS2Keyboard::keyboard_event_t evt_kb;

    while (1) {
        if (ps2kb.processing(&evt_kb)) {
            printf("[%d]:", evt_kb.type);
            for (int i = 0; i < evt_kb.length; i++) {
                printf("%02x ", evt_kb.scancode[i]);
            }
            printf("\n");
        }
    }
}

PS2Mouse class

#include "mbed.h"
#include "PS2Mouse.h"

PS2Mouse ps2ms(p23, p22); // CLK, DAT

int main() {
    PS2Mouse::mouse_event_t evt_ms;
    while (1) {
        if (ps2ms.processing(&evt_ms)) {
            printf("%c%c%c:%4d,%4d,%2d\n",
                evt_ms.left ? 'L' : '.',
                evt_ms.center ? 'C' : '.',
                evt_ms.right ? 'R' : '.',
                evt_ms.x, evt_ms.y, evt_ms.z);
        }
    }
}

References

Limits

  • Some PS/2 mouses will transmit data high rates. In this case, the internal buffer will overflow.
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