Revision 0:3a30eba5d8f7, committed 2016-01-27

Comitter:

Overdrivr

Date:

Wed Jan 27 17:39:36 2016 +0000

Child:

1:e51abb43c074

Commit message:

Port of github.com/Overdrivr/Telemetry to mbed. Current commit corresponds to release tagged 1.0.1

Changed in this revision

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/crc16.cpp	Wed Jan 27 17:39:36 2016 +0000
@@ -0,0 +1,33 @@
+#include "crc16.hpp"
+
+uint16_t crc16(uint8_t* data, uint32_t len)
+{
+    uint16_t rem  = 0;
+    for(uint16_t i = 0 ; i < len ; i++)
+    {
+        rem = crc16_recursive(data[i],rem);
+    }
+  return rem;
+ }
+
+uint16_t crc16_recursive(uint8_t byte, uint16_t remainder)
+{
+    uint16_t n = 16;
+
+    remainder  = remainder ^ (byte << (n-8));
+
+    for(uint16_t j = 1 ; j < 8 ; j++)
+    {
+        if(remainder & 0x8000)
+        {
+            remainder  = (remainder << 1) ^ 0x1021;
+        }
+        else
+        {
+            remainder  = remainder << 1;
+        }
+        remainder &= 0xffff;
+    }
+
+    return remainder;
+}
\ No newline at end of file

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/crc16.hpp	Wed Jan 27 17:39:36 2016 +0000
@@ -0,0 +1,11 @@
+#ifndef CRC16_H_
+#define CRC16_H_
+
+//From : https://en.wikipedia.org/wiki/Computation_of_cyclic_redundancy_checks
+
+#include "stdint.h"
+
+uint16_t crc16(uint8_t * data, uint32_t lenght);
+uint16_t crc16_recursive(uint8_t byte, uint16_t remainder);
+
+#endif
\ No newline at end of file

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/driver.hpp	Wed Jan 27 17:39:36 2016 +0000
@@ -0,0 +1,44 @@
+#include "MODSERIAL.h"
+
+// Driver implementation for telemetry (github.com/Overdrivr/Telemetry)
+// Don't forget in your main to aggregate the driver to telemetry (see below)
+/*
+  // Add this code to your main 
+  
+  TM_transport transport;
+  transport.read = read;
+  transport.write = write;
+  transport.readable = readable;
+  transport.writeable = writeable;
+
+  // Feed to transport to telemetry on init
+  init_telemetry(.., &transport);
+*/
+
+MODSERIAL pc(USBTX, USBRX);
+
+int32_t read(void * buf, uint32_t sizeToRead)
+{
+    *(uint8_t*)(buf) = pc.getc();
+    return 1;
+}
+
+int32_t readable()
+{
+    return pc.rxBufferGetCount();
+}
+
+int32_t write(void * buf, uint32_t sizeToWrite)
+{
+    char * ptr = (char *)buf;
+    for(uint32_t i = 0 ; i < sizeToWrite ; i++)
+    {
+        pc.putc(ptr[i]);
+    }
+    return 0;
+}
+
+int32_t writeable()
+{
+    return pc.writeable();
+}

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/framing.cpp	Wed Jan 27 17:39:36 2016 +0000
@@ -0,0 +1,184 @@
+#include "framing.hpp"
+
+typedef enum _state _state;
+enum _state
+{
+  IDLE, // No incoming frame is in process
+  ESCAPING, // incoming frame in process, next character to be escaped
+  ACTIVE // frame in process
+};
+
+typedef struct storage storage;
+struct storage
+{
+   uint8_t * ptr;
+   uint32_t size;
+   uint32_t cursor;
+
+};
+
+static storage incomingStorage;
+static storage outgoingStorage;
+
+int8_t safe_append(storage * s, uint8_t byte);
+
+static uint8_t SOF_;
+static uint8_t EOF_;
+static uint8_t ESC_;
+
+static _state incoming_state;
+
+void (*on_incoming_frame_cb)(uint8_t * storage, uint32_t occupiedSize);
+void (*on_error_cb)(int32_t errCode);
+
+void initialize_framing()
+{
+  incomingStorage.ptr = NULL;
+  outgoingStorage.ptr = NULL;
+
+  incomingStorage.size = 0;
+  outgoingStorage.size = 0;
+
+  incomingStorage.cursor = 0;
+  incomingStorage.cursor = 0;
+
+  SOF_ = 0xF7;
+  EOF_ = 0x7F;
+  ESC_ = 0x7D;
+
+  incoming_state = IDLE;
+}
+
+void outgoing_storage(uint8_t * buf, uint32_t bufSize)
+{
+  outgoingStorage.ptr = buf;
+  outgoingStorage.size = bufSize;
+}
+
+void begin()
+{
+  if(outgoingStorage.size == 0 || outgoingStorage.ptr == NULL)
+    return;
+
+  outgoingStorage.cursor = 0;
+
+  // Should not fail
+  safe_append(&outgoingStorage,SOF_);
+}
+
+void append(uint8_t byte)
+{
+  if(outgoingStorage.size == 0 || outgoingStorage.ptr == NULL)
+    return;
+
+  // byte == to flag, need to escape it
+  if(byte == SOF_ || byte == EOF_ || byte == ESC_)
+  {
+    if(!safe_append(&outgoingStorage,ESC_))
+      return;
+  }
+
+  if(!safe_append(&outgoingStorage,byte))
+    return;
+}
+
+void append2(uint16_t twobytes)
+{
+  uint8_t * ptr = (uint8_t*)(&twobytes);
+  append(ptr[0]);
+  append(ptr[1]);
+}
+
+void append4(uint32_t fourbytes)
+{
+  uint8_t * ptr = (uint8_t*)(&fourbytes);
+  append(ptr[0]);
+  append(ptr[1]);
+  append(ptr[2]);
+  append(ptr[3]);
+}
+
+uint32_t end()
+{
+  if(outgoingStorage.size == 0 || outgoingStorage.ptr == NULL)
+    return 0;
+
+  if(!safe_append(&outgoingStorage,EOF_))
+    return 0;
+
+  return outgoingStorage.cursor;
+}
+
+void incoming_storage(uint8_t * buf, uint32_t bufSize)
+{
+  incomingStorage.ptr = buf;
+  incomingStorage.size = bufSize;
+}
+
+void set_on_incoming_frame(void (*callback)(uint8_t * storage, uint32_t occupiedSize))
+{
+  on_incoming_frame_cb = callback;
+}
+
+void set_on_incoming_error(void (*callback)(int32_t errCode))
+{
+  on_error_cb = callback;
+}
+
+void feed(uint8_t byte)
+{
+  if(incomingStorage.size == 0 || incomingStorage.ptr == NULL)
+    return;
+
+  if(incoming_state == ESCAPING)
+  {
+    if(!safe_append(&incomingStorage,byte))
+    {
+      incoming_state = IDLE;
+      return;
+    }
+    incoming_state = ACTIVE;
+    return;
+  }
+
+  if(byte == SOF_)
+  {
+      incoming_state = ACTIVE;
+      incomingStorage.cursor = 0;
+      return;
+  }
+
+  if(incoming_state == ACTIVE)
+  {
+    if(byte == EOF_)
+    {
+        incoming_state = IDLE;
+        on_incoming_frame_cb(incomingStorage.ptr, incomingStorage.cursor);
+    }
+    // Escape next character
+    else if(byte == ESC_)
+    {
+        incoming_state = ESCAPING;
+    }
+    else
+    {
+      if(!safe_append(&incomingStorage,byte))
+      {
+        incoming_state = IDLE;
+        return;
+      }
+      incoming_state = ACTIVE;
+    }
+  }
+}
+
+int8_t safe_append(storage * s, uint8_t byte)
+{
+  // Not enough space for 1 more character
+  if(s->cursor + 1 >= s->size)
+    return 0;
+
+  s->ptr[s->cursor++] = byte;
+
+  return 1;
+}
\ No newline at end of file

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/framing.hpp	Wed Jan 27 17:39:36 2016 +0000
@@ -0,0 +1,25 @@
+#ifndef FRAMING_H_
+#define FRAMING_H_
+
+#include "stddef.h"
+#include "stdint.h"
+
+void initialize_framing();
+// Outgoing data
+// Set storage for the outgoing frame
+void outgoing_storage(uint8_t * buf, uint32_t bufSize);
+
+void begin();
+void append(uint8_t byte);
+void append2(uint16_t twobytes);
+void append4(uint32_t fourbytes);
+uint32_t end();
+
+// Incoming data
+// Set storage for the incoming data
+void incoming_storage(uint8_t * buf, uint32_t bufSize);
+
+void set_on_incoming_frame(void (*callback)(uint8_t * storage, uint32_t occupiedSize));
+void set_on_incoming_error(void (*callback)(int32_t errCode));
+void feed(uint8_t byte);
+#endif
\ No newline at end of file

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/telemetry.cpp	Wed Jan 27 17:39:36 2016 +0000
@@ -0,0 +1,313 @@
+#include "telemetry.hpp"
+#include "framing.hpp"
+#include "crc16.hpp"
+#include "string.h"
+
+static TM_state * statePtr;
+static TM_transport * transportPtr;
+static uint8_t incomingBuffer[INCOMING_BUFFER_SIZE];
+static uint8_t outgoingBuffer[OUTGOING_BUFFER_SIZE];
+static char topicBuffer[TOPIC_BUFFER_SIZE];
+
+static void (*userCallback)(TM_state * s, TM_msg * m);
+
+uint16_t header(TM_type type);
+uint16_t topic(const char * topic, uint16_t crc);
+uint16_t payload(const void * payload, uint32_t size, uint16_t crc);
+void frame(const char * t, TM_type type, const void * data, uint32_t datasize);
+void send(void * buf, uint32_t size);
+void on_incoming_frame(uint8_t * storage, uint32_t size);
+void on_incoming_error(int32_t errCode);
+void emptyCallback(TM_state * s, TM_msg * m);
+
+void init_telemetry(TM_state* s, TM_transport * t)
+{
+  statePtr = s;
+  transportPtr = t;
+  userCallback = emptyCallback;
+
+  // Setup framing
+  initialize_framing();
+  incoming_storage(incomingBuffer,INCOMING_BUFFER_SIZE);
+  outgoing_storage(outgoingBuffer, OUTGOING_BUFFER_SIZE);
+  set_on_incoming_frame(on_incoming_frame);
+  set_on_incoming_error(on_incoming_error);
+}
+
+uint32_t emplace(TM_msg* m, char * buf, size_t bufSize)
+{
+  if(m->type != TM_string)
+    return 0;
+
+  uint32_t size = m->size;
+
+  if(bufSize - 1 < size)
+    size = bufSize - 1;
+
+  strncpy(buf, (char*)(m->buffer), size);
+  buf[size] = '\0';
+
+  return 1;
+}
+
+uint32_t emplace_u8(TM_msg* m, uint8_t* dst)
+{
+  if(m->type != TM_uint8)
+    return 0;
+
+  memcpy(dst,m->buffer,1);
+  return 1;
+}
+
+uint32_t emplace_u16(TM_msg* m, uint16_t* dst)
+{
+  if(m->type != TM_uint16)
+    return 0;
+
+  memcpy(dst,m->buffer,2);
+  return 1;
+}
+
+uint32_t emplace_u32(TM_msg* m, uint32_t* dst)
+{
+  if(m->type != TM_uint32)
+    return 0;
+
+  memcpy(dst,m->buffer,4);
+  return 1;
+}
+
+uint32_t emplace_i8(TM_msg* m, int8_t* dst)
+{
+  if(m->type != TM_int8)
+    return 0;
+
+  memcpy(dst,m->buffer,1);
+  return 1;
+}
+
+uint32_t emplace_i16(TM_msg* m, int16_t* dst)
+{
+  if(m->type != TM_int16)
+    return 0;
+
+  memcpy(dst,m->buffer,2);
+  return 1;
+}
+
+uint32_t emplace_i32(TM_msg* m, int32_t* dst)
+{
+  if(m->type != TM_int32)
+    return 0;
+
+  memcpy(dst,m->buffer,4);
+  return 1;
+}
+
+uint32_t emplace_f32(TM_msg* m, float* dst)
+{
+  if(m->type != TM_float32)
+    return 0;
+
+  memcpy(dst,m->buffer,4);
+  return 1;
+}
+
+void publish(const char * t, char * msg)
+{
+  frame(t,TM_string,msg,strlen(msg));
+}
+
+void publish_u8(const char * t, uint8_t  msg)
+{
+  void * ptr = (void *)(&msg);
+  frame(t,TM_uint8,ptr,1);
+}
+
+void publish_u16(const char * t, uint16_t msg)
+{
+  void * ptr = (void *)(&msg);
+  frame(t,TM_uint16,ptr,2);
+}
+
+void publish_u32(const char * t, uint32_t msg)
+{
+  void * ptr = (void *)(&msg);
+  frame(t,TM_uint32,ptr,4);
+}
+
+void publish_i8(const char * t, int8_t   msg)
+{
+  void * ptr = (void *)(&msg);
+  frame(t,TM_int8,ptr,1);
+}
+
+void publish_i16(const char * t, int16_t  msg)
+{
+  void * ptr = (void *)(&msg);
+  frame(t,TM_int16,ptr,2);
+}
+
+void publish_i32(const char * t, int32_t  msg)
+{
+  void * ptr = (void *)(&msg);
+  frame(t,TM_int32,ptr,4);
+}
+
+void publish_f32(const char * t, float    msg)
+{
+  void * ptr = (void *)(&msg);
+  frame(t,TM_float32,ptr,4);
+}
+
+void subscribe(void (*callback)(TM_state* s, TM_msg* m))
+{
+  userCallback = callback;
+}
+
+void update_telemetry(float elapsedTime)
+{
+  uint32_t amount = transportPtr->readable();
+  for(uint32_t i = 0 ; i < amount ; i++)
+  {
+    uint8_t c;
+    transportPtr->read(&c,1);
+    feed(c);
+  }
+}
+
+uint16_t header(TM_type type)
+{
+  // header data
+  uint16_t h = type;
+  uint8_t * ptr = (uint8_t*)(&h);
+
+  // add data to frame
+  append2(h);
+
+  // compute crc and return it
+  return crc16(ptr, 2);
+}
+
+uint16_t topic(const char * t, uint16_t crc)
+{
+  const uint8_t * ptr = (uint8_t*)t;
+  for(uint32_t i = 0 ; i < strlen(t) ; i++)
+  {
+    // TODO : Replace with Huffman compression
+    append(ptr[i]);
+    crc = crc16_recursive(ptr[i], crc);
+  }
+  // Add NULL character
+  append(0);
+  return crc16_recursive(0,crc);
+}
+
+uint16_t payload(const void * p, uint32_t size, uint16_t crc)
+{
+  const uint8_t * ptr = (uint8_t*)p;
+  for(uint32_t i = 0 ; i < size ; i++)
+  {
+    append(ptr[i]);
+    crc = crc16_recursive(ptr[i], crc);
+  }
+  return crc;
+}
+
+void frame(const char * t, TM_type type, const void * data, uint32_t datasize)
+{
+  // start new frame
+  begin();
+
+  // header
+  uint16_t crc = header(type);
+
+  // topic
+  crc = topic(t, crc);
+
+  // payload
+  crc = payload(data, datasize, crc);
+
+  // crc
+  append2(crc);
+
+  // complete frame
+  uint32_t bytesAmount = end();
+
+  // send data
+  send(outgoingBuffer, bytesAmount);
+}
+
+void send(void * buf, uint32_t size)
+{
+  if(transportPtr->writeable() && size > 0)
+  {
+    transportPtr->write(outgoingBuffer, size);
+  }
+}
+
+void on_incoming_frame(uint8_t * storage, uint32_t size)
+{
+  if(size < 2)
+    return;
+  // Read header
+  uint16_t head;
+  uint8_t * ptr;
+  ptr = (uint8_t*)(&head);
+  memcpy(ptr,storage,2);
+
+  // Read topic
+  uint32_t cursor = 2;
+  uint32_t topicSize = 0;
+  while(cursor < size)
+  {
+    if(storage[cursor] == 0)
+      break;
+    topicSize++;
+    cursor++;
+  }
+
+  if(topicSize == 0)
+    return;
+
+  // payload = total - header - topic - /0 - crc
+  int32_t payloadSize = size - 2 - topicSize - 1 - 2;
+
+  if(payloadSize <= 0)
+    return;
+
+  // Check crc
+  uint16_t expected_crc = crc16(storage, size-2);
+  uint16_t rcv_crc;
+  ptr = (uint8_t*)(&rcv_crc);
+  memcpy(ptr,storage+size-2,2);
+
+  if(expected_crc != rcv_crc)
+    return;
+
+  // Store topic
+  char * t = (char*)(storage);
+  strcpy(topicBuffer, t + 2);
+
+  // ptr to beginning of payload
+  ptr = (uint8_t*)(storage) + (uint32_t)(2 + topicSize + 1);
+
+  TM_msg packet;
+  packet.topic = topicBuffer;
+  packet.type = (TM_type)head;
+  packet.buffer = (void *)(ptr);
+  packet.size = (uint32_t)payloadSize;
+
+  // Call callback
+  userCallback(statePtr,&packet);
+}
+
+void on_incoming_error(int32_t errCode)
+{
+  // TODO : Error management
+}
+
+void emptyCallback(TM_state * s, TM_msg * m)
+{
+  // Called only if the user forgot to subscribe a callback
+}

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/telemetry.hpp	Wed Jan 27 17:39:36 2016 +0000
@@ -0,0 +1,72 @@
+#ifndef TELEMETRY_H_
+#define TELEMETRY_H_
+
+#include "stddef.h"
+#include "stdint.h"
+
+#define INCOMING_BUFFER_SIZE 128
+#define OUTGOING_BUFFER_SIZE 128
+#define TOPIC_BUFFER_SIZE 64
+
+// Forward declaration of user state
+typedef struct TM_state TM_state;
+
+// Enumeration of supported message payloads
+enum TM_type {
+  TM_float32 = 0,
+  TM_uint8 = 1,
+  TM_uint16 = 2,
+  TM_uint32 = 3,
+  TM_int8 = 4,
+  TM_int16 = 5,
+  TM_int32 = 6,
+  TM_string = 7
+};
+typedef enum TM_type TM_type;
+
+// Data structure for received messages
+typedef struct TM_msg TM_msg;
+struct TM_msg {
+  TM_type type;
+  char * topic;
+  void * buffer;
+  uint32_t size;
+};
+
+// Data structure for holding transport interface
+typedef struct TM_transport TM_transport;
+struct TM_transport {
+  int32_t (*read)(void * buf, uint32_t sizeToRead);
+  int32_t (*readable)();
+  int32_t (*write)(void * buf, uint32_t sizeToWrite);
+  int32_t (*writeable)();
+};
+
+void init_telemetry(TM_state * s, TM_transport * t);
+
+// Decodes TM_msg buffer and emplaces its value into dst
+// Returns 0 if decoding was successful
+uint32_t emplace(TM_msg * m, char * buf, size_t bufSize);
+uint32_t emplace_u8(TM_msg * m, uint8_t * dst);
+uint32_t emplace_u16(TM_msg * m, uint16_t * dst);
+uint32_t emplace_u32(TM_msg * m, uint32_t * dst);
+uint32_t emplace_i8(TM_msg * m, int8_t * dst);
+uint32_t emplace_i16(TM_msg * m, int16_t * dst);
+uint32_t emplace_i32(TM_msg * m, int32_t * dst);
+uint32_t emplace_f32(TM_msg * m, float * dst);
+
+void publish(const char * topic, char * msg);
+void publish_u8(const char * topic, uint8_t msg);
+void publish_u16(const char * topic, uint16_t msg);
+void publish_u32(const char * topic, uint32_t msg);
+void publish_i8(const char * topic, int8_t msg);
+void publish_i16(const char * topic, int16_t msg);
+void publish_i32(const char * topic, int32_t msg);
+void publish_f32(const char * topic, float msg);
+
+void subscribe(void (*callback)(TM_state * s, TM_msg * m));
+
+void update_telemetry(float elapsedTime);
+
+
+#endif