Add arduino skecthes

2025-09-14 15:52:39 +02:00
parent b2eeaa2785
commit 4d77b77daf
3 changed files with 747 additions and 0 deletions
--- a/arduino/kbd/kbd.ino
+++ b/arduino/kbd/kbd.ino
@@ -0,0 +1,194 @@
+// keyboard wiring diagram: https://www.minuszerodegrees.net/5150/misc/5150_keyboard_reset.jpg
+
+constexpr int kClockPin = PC6;
+constexpr int kDataPin = PC4;
+
+constexpr int kBitDelayMicros = 100;
+constexpr int kCodeDelayMicros = 200;
+constexpr int kKeyDelayMicros = 100;
+
+void setup() {
+  // put your setup code here, to run once:
+  Serial.begin(115200);
+  pinMode(LED_BUILTIN, OUTPUT);
+
+  pinMode(kClockPin, INPUT);
+  pinMode(kDataPin, INPUT);
+
+  Serial.println("kbd 0.1");
+}
+
+// 0. reset
+// 0.0. clock line will be held low externally for 20 ms
+//      when back up, keyboard needs to clock 0xAA as a response
+//
+// 1. operation
+// 1.0. just directly clock out scan codes of pressed keys
+
+void sendCode(int code) {
+  Serial.printf("sending code 0x%02x\n", code);
+  // preconditions: clock and data pins are INPUT
+
+  while (digitalRead(kDataPin) == LOW || digitalRead(kClockPin) == LOW) {
+    // wait. we're not allowed to send
+  }
+
+  digitalWrite(kDataPin, LOW);
+  digitalWrite(kClockPin, LOW);
+
+  pinMode(kClockPin, OUTPUT);
+  delayMicroseconds(kBitDelayMicros);
+  pinMode(kClockPin, INPUT);
+ // delayMicroseconds(kDelayMicros);
+
+  for (int i = 0; i < 8; i++) {
+    if ((code & (1 << i)) == 0) {
+      // send a 0
+      pinMode(kDataPin, OUTPUT);
+    }  // else do nothing, it's already a 1
+    delayMicroseconds(kBitDelayMicros);
+
+    pinMode(kClockPin, OUTPUT);
+    delayMicroseconds(kBitDelayMicros);
+    pinMode(kDataPin, INPUT);
+    pinMode(kClockPin, INPUT);
+  }
+  delayMicroseconds(kCodeDelayMicros);
+}
+
+enum State {
+  kReady,
+  kMaybeReset,
+};
+
+constexpr int kResetDelay = 19;
+
+State state = State::kReady;
+int lastclocklow = 0;
+
+constexpr int kLetterCodes[] = {
+  0x1E,  // 'a'
+  0x30,
+  0x2E,
+  0x20,
+  0x12,
+  0x21,
+  0x22,
+  0x23,
+  0x17,
+  0x24,
+  0x25,
+  0x26,
+  0x32,
+  0x31,
+  0x18,
+  0x19,
+  0x10,
+  0x13,
+  0x1F,
+  0x14,
+  0x16,
+  0x2F,
+  0x11,
+  0x2D,
+  0x15,
+  0x2c,
+};
+
+constexpr int kNumberCodes[] = {
+  0x0B,  // '0'
+  0x02,
+  0x03,
+  0x04,
+  0x05,
+  0x06,
+  0x07,
+  0x08,
+  0x09,
+  0x0A,
+};
+
+void sendNormalCode(int code) {
+  sendCode(code);
+  sendCode(code | 0x80);
+}
+
+void sendShiftCode(int code) {
+  sendCode(42); // left shift
+  sendNormalCode(code);
+  sendCode(42 | 0x80);
+}
+
+void sendAsciiChar(int c) {
+  if (c >= 'a' && c <= 'z') {
+    return sendNormalCode(kLetterCodes[c - 'a']);
+  } else if (c >= '0' && c <= '9') {
+    return sendNormalCode(kNumberCodes[c - '0']);
+  } else if (c >= 'A' && c <= 'Z') {
+    return sendShiftCode(kLetterCodes[c - 'A']);
+  }
+  switch (c) {
+    case '-': return sendNormalCode(12);
+    case '=': return sendNormalCode(13);
+    case '[': return sendNormalCode(26);
+    case ']': return sendNormalCode(27);
+    case ';': return sendNormalCode(39);
+    case '\'': return sendNormalCode(40);
+    case ',': return sendNormalCode(51);
+    case '.': return sendNormalCode(52);
+    case '/': return sendNormalCode(53);
+    case ' ': return sendNormalCode(57);
+    case '\n': return sendNormalCode(28);
+
+    case '!': return sendShiftCode(2);
+    case '@': return sendShiftCode(3);
+    case '#': return sendShiftCode(4);
+    case '$': return sendShiftCode(5);
+    case '%': return sendShiftCode(6);
+    case '^': return sendShiftCode(7);
+    case '&': return sendShiftCode(8);
+    case '*': return sendShiftCode(9);
+    case '(': return sendShiftCode(10);
+    case ')': return sendShiftCode(11);
+    case '_': return sendShiftCode(12);
+    case '+': return sendShiftCode(13);
+
+    case '{': return sendShiftCode(26);
+    case '}': return sendShiftCode(27);
+    case ':': return sendShiftCode(39);
+    case '"': return sendShiftCode(40);
+    case '<': return sendShiftCode(51);
+    case '>': return sendShiftCode(52);
+    case '?': return sendShiftCode(53);
+  }
+}
+
+void loop() {
+  static int led_counter = 0;
+  static int led = HIGH;
+  if (led_counter > 400000) {
+    led_counter = 0;
+    led = (led == HIGH) ? LOW : HIGH;
+    digitalWrite(LED_BUILTIN, led);
+  }
+  led_counter += 1;
+
+  int clockp = digitalRead(kClockPin);
+  if (state == State::kReady && clockp == LOW) {
+    state = State::kMaybeReset;
+    lastclocklow = millis();
+  } else if (state == State::kMaybeReset) {
+    if (clockp == HIGH && millis() - lastclocklow > kResetDelay) {
+      delay(1);
+      state = State::kReady;
+      sendCode(0xaa);
+      Serial.println("Reset!");
+    }
+  }
+
+  if (Serial.available() > 0) {
+    int c = Serial.read();
+    sendAsciiChar(c);
+    //delayMicroseconds(kKeyDelayMicros);
+  }
+}