Sleep the MCU 250ms after relay on switches, to avoid brownouts. Scan the pushbutton for 100ms to ensure it was still pressed, to avoid RFI from triggering

src/channel.c

@@ -161,6 +161,13 @@ void channel_set(int idx, bool state) {
   }
 
   mqtt_publish_stat("channel", "{idx: %d, relay_state: %d}", idx, channel_get(idx));
+
+  if (state) {
+    // Sleep 250ms after toggling a relay to avoid cheaper boards from
+    // suffering a brownout and rebooting the MCU in case several channels
+    // are switched in short succession.
+    mgos_msleep(250);
+  }
 }
 
 bool channel_get(int idx) {
@@ -186,6 +193,18 @@ void channel_handler(int gpio, void *arg) {
     LOG(LL_INFO, ("RPC triggered channel %d", idx));
   } else {
     LOG(LL_INFO, ("Button on GPIO %d triggered channel %d", gpio, idx));
+    // Scan the button for 100ms to ensure it is still pressed. This is to avoid
+    // RFI noise from triggering GPIO pins.
+    for (int i=0; i<10; i++) {
+      bool value;
+
+      mgos_msleep(10);
+      value=mgos_gpio_read(gpio);
+      if (value) {
+        LOG(LL_WARN, ("Button on GPIO %d no longer pressed after %d ms, skipping", gpio, 10*i));
+        return;
+      }
+    }
   }
 
   state = channel_get(idx);