Apologies up front, I am pretty new to Arduino programming.
I have an Adafruit Trinket which I have managed to get working as a USB volume control. However, I wanted to add buttons on to the remaining pins 4 and 5 for track changing etc.
I added a little extra code to initialise the buttons, as pull ups, and used state change detection to prevent constant activations. However, despite this, the button is being constantly activated despite me doing nothing. Also, when I do ground the pin (press the button) and trinket starts misbehaving and windows throws up a usb malfunction warning.
I'm sure it's something simple, or I've managed to fry my chip (although the volume control and rotary encoder switch still work fine.
Any help would be greatly appreciated.
#include "TrinketHidCombo.h"
#define PIN_ENCODER_A 2
#define PIN_ENCODER_B 0
#define TRINKET_PINx PINB
#define PIN_ENCODER_SWITCH 1
#define BUTTON_1 3
static uint8_t enc_prev_pos = 0;
static uint8_t enc_flags = 0;
static char sw_was_pressed = 0;
int button1State = 0;
int lastButton1State = 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);
pinMode(BUTTON_1, INPUT);
digitalWrite(BUTTON_1, HIGH);
pinMode(PIN_ENCODER_SWITCH, INPUT);
// the switch is active-high, not active-low
// since it shares the pin with Trinket's built-in LED
// the LED acts as a pull-down resistor
digitalWrite(PIN_ENCODER_SWITCH, LOW);
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);
}
// Rotary Encoder Switch
// remember that the switch is active-high
if (bit_is_set(TRINKET_PINx, PIN_ENCODER_SWITCH))
{
if (sw_was_pressed == 0) // only on initial press, so the keystroke is not repeated while the button is held down
{
TrinketHidCombo.pressMultimediaKey(MMKEY_PLAYPAUSE);
delay(5); // debounce delay
}
sw_was_pressed = 1;
}
else
{
if (sw_was_pressed != 0) {
delay(5); // debounce delay
}
sw_was_pressed = 0;
}
// Button 1
button1State = digitalRead(BUTTON_1);
if (button1State != lastButton1State) {
if (button1State == LOW) {
TrinketHidCombo.pressMultimediaKey(MMKEY_MUTE);
}
delay (50);
}
lastButton1State = button1State;
TrinketHidCombo.poll(); // check if USB needs anything done
}