Pin deboncing

1 files changed, 17 insertions, 0 deletions

diff --git a/src/gpio.cpp b/src/gpio.cpp
index f3f600f..e76368a 100644
--- a/src/gpio.cpp
+++ b/src/gpio.cpp
@@ -24,6 +24,15 @@ typedef uint32_t pin_notification_t;
 static unsigned long pressedTime = 0;
 static unsigned long releasedTime = 0;
 
+typedef struct
+{
+    uint32_t last_change;
+    uint32_t last_level;
+    uint32_t pressed;
+} InputInfo_t;
+
+static volatile InputInfo_t inputs[NUM_DIGITAL_PINS];
+
 static struct
 {
 
@@ -50,6 +59,7 @@ void de::uvok::badge::gpio_init(void)
         pinMode(p, GPIO_MODE_INPUT);
         // simply use pin number as arg
         attachInterruptArg(p, gpio_pin_irq, (void *)(ptrdiff_t)p, CHANGE);
+        inputs[p].last_level = digitalRead(p);
     }
 #endif
 }
@@ -97,6 +107,13 @@ static void gpio_loop(void *ctx)
 static ARDUINO_ISR_ATTR void gpio_pin_irq(void *arg)
 {
     uint8_t pin_no = (uint8_t)(ptrdiff_t)arg;
+    uint32_t now = millis();
+    // Elecrow inputs - the selector - are very dirty...
+    const bool is_dirty = now - inputs[pin_no].last_change < 100;
+    inputs[pin_no].last_change = now;
+    if (is_dirty)
+        return;
+
     int pinLevel = digitalRead(pin_no);
 
     pin_notification_t send = (pinLevel << 8) | (pin_no);