AT switch demos

Adding AT switch demos for the TRRS Trinkey

Author: BlitzCityDIY

TRRS_Trinkey_Demos/CircuitPython_AT_Demo/code.py

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+# SPDX-FileCopyrightText: 2024 ladyada for Adafruit Industries
+#
+# SPDX-License-Identifier: MIT
+
+import time
+import board
+import digitalio
+import usb_hid
+from adafruit_hid.keyboard import Keyboard
+from adafruit_hid.keycode import Keycode
+
+# HID Keyboard setup
+keyboard = Keyboard(usb_hid.devices)
+
+# Define pins for switches and grounds
+tip_switch = digitalio.DigitalInOut(board.TIP_SWITCH)
+tip_switch.direction = digitalio.Direction.INPUT
+tip_switch.pull = digitalio.Pull.UP
+
+sleeve = digitalio.DigitalInOut(board.SLEEVE)
+sleeve.direction = digitalio.Direction.OUTPUT
+sleeve.value = False
+
+ring_2 = digitalio.DigitalInOut(board.RING_2)
+# Set TIP and RING_1 initially as outputs to low for jack detection
+tip = digitalio.DigitalInOut(board.TIP)
+tip.direction = digitalio.Direction.OUTPUT
+tip.value = False
+
+ring_1 = digitalio.DigitalInOut(board.RING_1)
+ring_1.direction = digitalio.Direction.OUTPUT
+ring_1.value = False
+
+# Track the state of cable insertion
+last_cable_state = False
+
+while True:
+    # Drive TIP low and check TIP_SWITCH to detect if cable is inserted
+    tip.direction = digitalio.Direction.OUTPUT
+    tip.value = False
+    time.sleep(0.001)  # Wait a moment for the state to stabilize
+    cable_inserted = tip_switch.value  # Active low when cable is inserted
+
+    # Handle the detected state change for cable insertion
+    if cable_inserted and not last_cable_state:
+        print("inserted!")
+        time.sleep(0.25)  # Debounce and allow time for complete insertion
+
+    last_cable_state = cable_inserted
+
+    if cable_inserted:
+        # Now configure TIP and RING_1 as inputs with pull-ups
+        ring_2.direction = digitalio.Direction.OUTPUT
+        ring_2.value = False
+        tip.direction = digitalio.Direction.INPUT
+        tip.pull = digitalio.Pull.UP
+        sleeve.direction = digitalio.Direction.INPUT
+        sleeve.pull = digitalio.Pull.UP
+
+        # Check the switches and send keycodes
+        keycode = []
+        if not tip.value:
+            print("A")
+            keycode.append(Keycode.A)
+        if not sleeve.value:
+            print("B")
+            keycode.append(Keycode.B)
+
+        if keycode:
+            keyboard.send(*keycode)
+        else:
+            keyboard.release_all()
+    else:
+        keyboard.release_all()
+
+    time.sleep(0.01)  # Sample at 100 Hz

TRRS_Trinkey_Demos/TRRS_Trinkey_AT_Demo/TRRS_Trinkey_AT_Demo.ino

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+// SPDX-FileCopyrightText: 2024 ladyada for Adafruit Industries
+//
+// SPDX-License-Identifier: MIT
+
+#include "Adafruit_TinyUSB.h"
+
+// HID report descriptor using TinyUSB's template
+// Single Report (no ID) descriptor
+uint8_t const desc_hid_report[] = {
+  TUD_HID_REPORT_DESC_KEYBOARD()
+};
+
+Adafruit_USBD_HID usb_hid;
+
+#define TIP_KEYCODE  HID_KEY_A
+#define RING_KEYCODE  HID_KEY_B
+
+uint8_t allpins[] = {PIN_TIP, PIN_RING1, PIN_RING2, PIN_SLEEVE};
+
+bool cableinserted = false;
+bool last_cablestate = false;
+uint32_t last_i2cscan = 0;
+ 
+void setup() {
+  Serial.begin(115200);
+  //while (!Serial) { yield(); delay(10); }     // wait till serial port is opened
+
+  usb_hid.setBootProtocol(HID_ITF_PROTOCOL_KEYBOARD);
+  usb_hid.setPollInterval(2);
+  usb_hid.setReportDescriptor(desc_hid_report, sizeof(desc_hid_report));
+  usb_hid.setStringDescriptor("TRRS Trinkey Keyboard");
+  usb_hid.begin();
+
+}
+
+void loop() {
+  delay(10); // sample every 10 ms
+
+  uint8_t keycode[6] = { 0 };
+  uint8_t count = 0;
+  // used to avoid send multiple consecutive zero report for keyboard
+  static bool keyPressedPreviously = false;
+
+  pinMode(PIN_TIP, OUTPUT);
+  digitalWrite(PIN_TIP, LOW);
+  pinMode(PIN_TIP_SWITCH, INPUT_PULLUP);
+  cableinserted = digitalRead(PIN_TIP_SWITCH);
+  
+  if (cableinserted && !last_cablestate) {
+    Serial.println("inserted!");
+    delay(250);  // give em a quarter second to plug completely
+  }
+  
+  last_cablestate = cableinserted;
+
+  // Wake up host if we are in suspend mode
+  if ( TinyUSBDevice.suspended() && count ) {
+    TinyUSBDevice.remoteWakeup();
+  }
+  // skip if hid is not ready e.g still transferring previous report
+  if ( !usb_hid.ready() ) return;
+  
+  if (!cableinserted) {
+    keyPressedPreviously = false;
+    usb_hid.keyboardRelease(0);
+    return;
+  }
+  // make two inputs
+  pinMode(PIN_TIP, INPUT_PULLUP);
+  pinMode(PIN_RING1, INPUT_PULLUP);
+
+  // make two 'ground' pins
+  pinMode(PIN_SLEEVE, OUTPUT);
+  digitalWrite(PIN_SLEEVE, LOW);
+  pinMode(PIN_RING2, OUTPUT);
+  digitalWrite(PIN_RING2, LOW);
+
+  delay(1);
+  
+  if (!digitalRead(PIN_TIP)) {
+    keycode[0] = TIP_KEYCODE;
+    count++;
+  }
+  if (!digitalRead(PIN_RING1)) {
+    keycode[1] = RING_KEYCODE;
+    count++;
+  }  
+
+  if (count) {   // Send report if there is key pressed
+    uint8_t const report_id = 0;
+    uint8_t const modifier = 0;
+
+    keyPressedPreviously = true;
+    usb_hid.keyboardReport(report_id, modifier, keycode);
+  }
+  else
+  {
+    // Send All-zero report to indicate there is no keys pressed
+    // Most of the time, it is, though we don't need to send zero report
+    // every loop(), only a key is pressed in previous loop()
+    if ( keyPressedPreviously )
+    {
+      keyPressedPreviously = false;
+      usb_hid.keyboardRelease(0);
+    }
+  }
+}