Script for debugging I2c comms with beaglebone.

i2c_bb/Makefile

@@ -0,0 +1,5 @@
+SYSTEM_LIBS = Wire Wire/utility
+USER_LIBS = jlewallen
+
+include ../Makefile.env
+include ../Makefile.master

i2c_bb/i2c_bb.ino

@@ -0,0 +1,135 @@
+#include <Wire.h>
+#include <printf.h>
+
+#define MASTER
+
+typedef struct _message_t {
+  uint8_t size;
+  uint8_t data[64];
+  _message_t *next;
+} message_t;
+
+static message_t *queue = NULL;
+static uint32_t previous = 0;
+static uint32_t bytesReceived = 0;
+static uint32_t bytesReceivedPrinted = 0;
+static uint32_t bytesSent = 0;
+static uint32_t bytesSentPrinted = 0;
+
+void blink(int16_t times, int16_t onTime, int16_t offTime) {
+  for (int i = 0; i < times; ++i) {
+    digitalWrite(13, HIGH);
+    delay(onTime);
+    digitalWrite(13, LOW);
+    delay(offTime);
+  }
+}
+
+void blink(int16_t times) {
+  blink(times, 250, 250);
+}
+
+void received(int16_t howMany) {
+  #ifdef CAPTURE
+  message_t *message = (message_t *)malloc(sizeof(message_t));
+  message->size = 0;
+  // uint8_t previous = millis();
+  while (message->size < 1/* && millis() - previous < 50*/) {
+    if (Wire.available()) {
+      message->data[message->size++] = Wire.read();
+      // previous = millis();
+      bytesReceived++;
+    }
+  }
+  message->next = queue;
+  queue = message;
+  #else
+  while (1) {
+    while (Wire.available() == 0) { }
+    uint8_t i = Wire.read();
+    bytesReceived++;
+    if (i == 0) {
+      break;
+    }
+  }
+  #endif
+}
+
+void requested() {
+  Wire.write((byte)0xdd);
+  bytesSent++;
+}
+
+void setup() {
+  Serial.begin(9600);
+  printf_begin();
+  pinMode(13, OUTPUT);
+
+  Wire.begin(0x21);
+  Wire.onReceive(received);
+  Wire.onRequest(requested);
+  blink(3);
+
+  printf("Listening on 0x21\n\r");
+}
+
+void loop() {
+  if (millis() - previous > 500) {
+    printf(".");
+    digitalWrite(13, !digitalRead(13));
+    previous = millis();
+  }
+  /*
+  Wire.beginTransmission(1);
+  Wire.write(states[number]);
+  Wire.endTransmission();
+  delay(100);
+  digitalWrite(13, LOW);
+  delay(1000);
+
+  number = (number + 1) % (sizeof(states));
+  if (number == 0) {
+    Wire.beginTransmission(1);
+    Wire.write(1 << 6);
+    Wire.write((byte)100);
+    Wire.write((byte)0);
+    Wire.write((byte)0);
+    Wire.endTransmission();
+    delay(1000);
+    Wire.beginTransmission(1);
+    Wire.write(1 << 6);
+    Wire.write((byte)0);
+    Wire.write((byte)100);
+    Wire.write((byte)0);
+    Wire.endTransmission();
+    delay(1000);
+    Wire.beginTransmission(1);
+    Wire.write(1 << 6);
+    Wire.write((byte)0);
+    Wire.write((byte)0);
+    Wire.write((byte)100);
+    Wire.endTransmission();
+    delay(1000);
+  }
+  */
+
+  /*
+  Wire.requestFrom(0x1, 1);
+  if (Wire.available()) {
+    number = Wire.read() % 5;
+  }
+  */
+  if (bytesReceivedPrinted != bytesReceived || bytesSentPrinted != bytesSent) {
+    bytesReceivedPrinted = bytesReceived;
+    bytesSentPrinted = bytesSent;
+    printf("Received %lu %lu\n\r", bytesReceived, bytesSent);
+  }
+  while (queue != NULL) {
+    message_t *next = queue->next;
+    printf("Message sz=%d (%lu)\n\r", queue->size, bytesReceived);
+    free(queue);
+    queue = next;
+  }
+
+  delay(100);
+}