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@crossdjinn
Created February 10, 2019 18:30
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#include "TrinketHidCombo.h"
#define PIN_ENCODER_A 4
#define PIN_ENCODER_B 5
#define TRINKET_PINx PINB
static uint8_t enc_prev_pos = 0;
static uint8_t enc_flags = 0;
void setup()
{
// set pins as input with internal pull-up resistors enabled
pinMode(PIN_ENCODER_A, INPUT);
pinMode(PIN_ENCODER_B, INPUT);
digitalWrite(PIN_ENCODER_A, HIGH);
digitalWrite(PIN_ENCODER_B, HIGH);
TrinketHidCombo.begin(); // start the USB device engine and enumerate
// get an initial reading on the encoder pins
if (digitalRead(PIN_ENCODER_A) == LOW) {
enc_prev_pos |= (1 << 0);
}
if (digitalRead(PIN_ENCODER_B) == LOW) {
enc_prev_pos |= (1 << 1);
}
}
void loop()
{
int8_t enc_action = 0; // 1 or -1 if moved, sign is direction
// note: for better performance, the code will now use
// direct port access techniques
// http://www.arduino.cc/en/Reference/PortManipulation
uint8_t enc_cur_pos = 0;
// read in the encoder state first
if (bit_is_clear(TRINKET_PINx, PIN_ENCODER_A)) {
enc_cur_pos |= (1 << 0);
}
if (bit_is_clear(TRINKET_PINx, PIN_ENCODER_B)) {
enc_cur_pos |= (1 << 1);
}
// if any rotation at all
if (enc_cur_pos != enc_prev_pos)
{
if (enc_prev_pos == 0x00)
{
// this is the first edge
if (enc_cur_pos == 0x01) {
enc_flags |= (1 << 0);
}
else if (enc_cur_pos == 0x02) {
enc_flags |= (1 << 1);
}
}
if (enc_cur_pos == 0x03)
{
// this is when the encoder is in the middle of a "step"
enc_flags |= (1 << 4);
}
else if (enc_cur_pos == 0x00)
{
// this is the final edge
if (enc_prev_pos == 0x02) {
enc_flags |= (1 << 2);
}
else if (enc_prev_pos == 0x01) {
enc_flags |= (1 << 3);
}
// check the first and last edge
// or maybe one edge is missing, if missing then require the middle state
// this will reject bounces and false movements
if (bit_is_set(enc_flags, 0) && (bit_is_set(enc_flags, 2) || bit_is_set(enc_flags, 4))) {
enc_action = 1;
}
else if (bit_is_set(enc_flags, 2) && (bit_is_set(enc_flags, 0) || bit_is_set(enc_flags, 4))) {
enc_action = 1;
}
else if (bit_is_set(enc_flags, 1) && (bit_is_set(enc_flags, 3) || bit_is_set(enc_flags, 4))) {
enc_action = -1;
}
else if (bit_is_set(enc_flags, 3) && (bit_is_set(enc_flags, 1) || bit_is_set(enc_flags, 4))) {
enc_action = -1;
}
enc_flags = 0; // reset for next time
}
}
enc_prev_pos = enc_cur_pos;
if (enc_action > 0) {
TrinketHidCombo.pressMultimediaKey(MMKEY_VOL_UP);
}
else if (enc_action < 0) {
TrinketHidCombo.pressMultimediaKey(MMKEY_VOL_DOWN);
}
else {
TrinketHidCombo.poll(); // do nothing, check if USB needs anything done
}
}
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