mirror of
https://github.com/jscrane/r65emu.git
synced 2024-12-25 22:31:51 +00:00
86 lines
1.5 KiB
C++
86 lines
1.5 KiB
C++
#include <Arduino.h>
|
|
#include "ps2drv.h"
|
|
|
|
#define BUFFER_SIZE 16
|
|
static volatile uint8_t buffer[BUFFER_SIZE];
|
|
static volatile uint8_t head, tail;
|
|
static uint8_t DataPin;
|
|
|
|
// The ISR for the external interrupt
|
|
void ps2interrupt(void)
|
|
{
|
|
static uint8_t bitcount=0;
|
|
static uint8_t incoming=0;
|
|
static uint32_t prev_ms=0;
|
|
uint32_t now_ms;
|
|
uint8_t n, val;
|
|
|
|
val = digitalRead(DataPin);
|
|
now_ms = millis();
|
|
if (now_ms - prev_ms > 250) {
|
|
bitcount = 0;
|
|
incoming = 0;
|
|
}
|
|
prev_ms = now_ms;
|
|
n = bitcount - 1;
|
|
if (n <= 7) {
|
|
incoming |= (val << n);
|
|
}
|
|
bitcount++;
|
|
if (bitcount == 11) {
|
|
uint8_t i = head + 1;
|
|
if (i == BUFFER_SIZE) i = 0;
|
|
if (i != tail) {
|
|
buffer[i] = incoming;
|
|
head = i;
|
|
}
|
|
bitcount = 0;
|
|
incoming = 0;
|
|
}
|
|
}
|
|
|
|
bool PS2Driver::available() {
|
|
if (head == tail)
|
|
return false;
|
|
|
|
uint8_t i = tail+1;
|
|
if (i == BUFFER_SIZE) i = 0;
|
|
if (buffer[i] == 0xf0)
|
|
return i != head;
|
|
return true;
|
|
}
|
|
|
|
unsigned PS2Driver::read2() {
|
|
if (head == tail)
|
|
return 0;
|
|
|
|
uint8_t i = tail+1;
|
|
if (i == BUFFER_SIZE) i = 0;
|
|
tail = i;
|
|
if (buffer[i] != 0xf0)
|
|
return buffer[i];
|
|
return 0xf000 | read2();
|
|
}
|
|
|
|
unsigned PS2Driver::peek() {
|
|
if (head == tail)
|
|
return 0;
|
|
|
|
uint8_t i = tail+1;
|
|
if (i == BUFFER_SIZE) i = 0;
|
|
if (buffer[i] == 0xf0) {
|
|
if (++i == BUFFER_SIZE) i = 0;
|
|
return 0xf000 | buffer[i];
|
|
}
|
|
return buffer[i];
|
|
}
|
|
|
|
void PS2Driver::begin(uint8_t data_pin, uint8_t irq_pin)
|
|
{
|
|
DataPin = data_pin;
|
|
pinMode(irq_pin, INPUT_PULLUP);
|
|
pinMode(data_pin, INPUT_PULLUP);
|
|
attachInterrupt(irq_pin, ps2interrupt, FALLING);
|
|
head = tail = 0;
|
|
}
|