add Arduino source for TCS control. Porting is not finished yet, but it already opens the door periodically

source/TcsBus.cpp

@@ -0,0 +1,121 @@
+#include <Arduino.h>
+#include "TcsBus.h"
+
+#define TCS_OVERSAMPLING    8
+#define TCS_BAUDRATE      475
+
+
+//tcs_bus datagrams
+static const unsigned char acknowledge[]   = {0,0,0,1,0,1,0,1,1,0};
+static const unsigned char ack_audio_on[]  = {0,0,0,1,0,1,0,0,1,1,0,0};
+static const unsigned char doorbell[]      = {0,0,0,1,1,0,1,0,1,0,1,1,0,1,1,0,1,1,0,1,1,0,1,1,0,0,1,1,0,1,0,1,0,1,0,0,1,1,0,0,1,0,1,0,1,0,1,0,0,1};
+static const unsigned char door_open[]     = {0,0,0,1,0,1,0,1,1,0,1,0,1,1,0,0,1,0,1,0,1,0,1,0};
+static const unsigned char master_hmmmm[]  = {0,0,0,1,0,1,0,0,1,0,1,0,0,1,0,0,1,0,1,0,1,0,1,0,1};
+static const unsigned char pickup[]        = {0,0,0,1,1,0,1,0,0,1,1,0,1,1,0,1,1,0,1,1,0,1,1,0,1,1,0,0,1,1,0,1,0,1,0,1,0,0,1,1,0,0,1,0,1,0,1,0,1,0,0};
+
+//volatile uint8_t bitIndex = 25;
+//const uint8_t datagram[] = { 0,0,0,1,0,1,0,1,1,0,1,0,1,1,0,1,0,1,0,1,0,1,0,0,    1 };
+static const unsigned char hang_up[]       = {0,0,0,1,0,1,0,0,1,1,0,1,0,1,0,0,1,0,1,0,1,0,1,0};
+static const unsigned char post_hang_up[]  = {0,0,0,1,0,1,0,0,1,0,1,0,1,1,0,1,0,1,0,1,0,1,0,0};
+static const unsigned char light[]         = {0,0,0,1,0,1,0,1,1,0,1,0,0,1,0,1,0,1,0,1,0,1,0,0};
+
+TcsBus::TcsBus(int sendPin, int receivePin) :
+  sendPin { sendPin },
+  receivePin { receivePin },
+  state { SamplingState::IDLE },
+  rxBits { 0 },
+  oversamplingStep { 0 }
+{
+
+}
+static hw_timer_t* timer = NULL;
+static TcsBus* tcsInstance = NULL;
+static void onTimer(void)
+{
+  tcsInstance->TimeBase();
+}
+
+static bool TimerSetup(TcsBus* inst)
+{
+  if(timer != NULL) return false; //already set up
+
+  tcsInstance = inst;
+  //time base is 80 MHz, which will be divided by the value from timerBegin, and then
+  //a counter increments until it reaches the value from timerAlarmWrite. onTimer will then be fired as a callback.
+  //80000000 / 50 / 421 = 3800.47 Hz = 8 * 475.06
+  timer = timerBegin(0, 50, true);
+  timerAttachInterrupt(timer, &onTimer, true);
+  timerAlarmWrite(timer, 421, true);
+  timerAlarmEnable(timer);
+  return true;
+}
+
+void TcsBus::begin()
+{
+  //Pin setup
+  pinMode(receivePin, INPUT);
+  pinMode(sendPin, OUTPUT);
+  digitalWrite(sendPin, LOW); //disable sending for now
+pinMode(0, OUTPUT);
+  TimerSetup(this);
+}
+
+void TcsBus::TimeBase()
+{
+  static int tmp = 0;
+  static bool send = false;
+  static int sendIdx = 0;
+  static int over = 0;
+tmp++;
+
+  if(tmp == 3000) {
+    send = true;
+    sendIdx = 0;
+    over = 0;
+  }
+
+  if(send) {
+    over++;
+    if(over == 8) {
+      over = 0;
+      if(sendIdx >= sizeof(door_open)) {
+        digitalWrite(sendPin, LOW);
+        send = false;
+        tmp = 0;
+      } else {
+        digitalWrite(sendPin, (door_open[sendIdx++]) ? LOW : HIGH);
+      }
+    }
+  }
+
+  bool sample = digitalRead(receivePin);
+
+  digitalWrite(0, sample == 0 ? LOW : HIGH);
+return;
+
+  switch(state) {
+    case SamplingState::IDLE: {
+      if(sample) {
+        state = SamplingState::RECEIVE;
+      } else {
+        break;
+      }
+    } //fall through
+
+    case SamplingState::RECEIVE: {
+
+    } break;
+
+    case SamplingState::TRANSMIT: {
+      static int i = 0;
+      i++;
+      if(i == 1000)
+      {
+        digitalWrite(sendPin, HIGH);
+      } else if(i > 1000) {
+        digitalWrite(sendPin, LOW);
+        i = 0;
+      }
+    } break;
+  }
+}

source/TcsBus.h

@@ -0,0 +1,28 @@
+#ifndef TCS_BUS_H_
+#define TCS_BUS_H_ 1
+#include <cstdint>
+
+class TcsBus {
+public:
+	TcsBus(int sendPin, int receivePin);
+  void begin();
+  void TimeBase();
+
+private:
+  int sendPin;
+  int receivePin;
+
+  enum class SamplingState
+  {
+      IDLE       = 0,
+      RECEIVE    = 1,
+      TRANSMIT   = 2,
+  };
+
+  SamplingState state;
+  uint16_t rxBits;
+  uint8_t oversamplingStep;
+  bool lastSample;
+};
+
+#endif //TCS_BUS_H_

source/source.ino

@@ -0,0 +1,44 @@
+#include <Wire.h>
+#include "TcsBus.h"
+
+#define PCA9554_ADDR 0x20 //PCA9554 = 0 1 0 0 a2 a1 a0
+
+#define PIN_AUDIO_READ  0
+#define PIN_API_SWITCH  4
+#define PIN_TCS_READ   13
+#define PIN_TCS_SEND   14
+#define PIN_AUDIO_SEND 17
+
+TcsBus tcs(PIN_TCS_SEND, PIN_TCS_READ);
+
+static uint32_t ms_old = 0;
+
+void setup() {
+  // put your setup code here, to run once:
+  Wire.begin();
+  Serial.begin(115200);
+
+  tcs.begin();
+
+  ms_old = millis();
+}
+
+
+void i2cScan() {
+  for(uint8_t a = 0; a < 0x80; a++) {
+    Wire.beginTransmission(a);
+    byte error = Wire.endTransmission();
+    if(!error) Serial.printf("i2cScan: found 0x%0x\n", a);
+  }
+}
+
+void loop() {
+  uint32_t ms = millis();
+  if(ms_old != ms) {
+    if(ms_old < ms) ms_old++; else ms_old = ms; //prevent overflow
+
+    if(!(ms & 1023)) {
+      i2cScan();
+    }
+  }
+}