add c source

src/dataframe.cpp

@@ -0,0 +1,190 @@
+/*
+ * @file dataframe.c
+ *
+ *  @date: 31. 12. 2022
+ *  @author: juraj
+ *
+ *  @brief Simple Data Frame
+ *
+ *  Structure of data frame:
+ * - starting byte (0xCC)
+ * - length of frame: count of bytes in payload. The first 2 bytes is not included to overal length. Maximum length: 254 (0xFE)
+ * - payload
+ * - CRC8
+ *
+ *  Supported data types:
+ *  - uint8_t, int8_t
+ *  - uint16_t, int16_t
+ *  - uint32_t, int32_t
+ *  - float
+ *
+ *  \code{.c}
+    void main(){
+		uint8_t data[128];
+
+	    packet_create(data, 128);
+		packet_add_uint8(0xAB);
+		packet_add_uint16(0xABCD);
+		packet_add_uint32(0x12345678);
+		packet_add_float(0.265);
+
+		int data_length = packet_commit();
+    }
+ * \endcode
+ *
+ */
+
+#include "dataframe.h"
+
+uint8_t crc8(uint8_t crc, uint8_t Size, uint8_t *Buffer)
+{
+    // https://community.st.com/s/question/0D50X0000CDmAkpSQF/calculate-crc8
+    static const unsigned char CrcTable[] = { // 0x97 Polynomial Table, 8-bit,
+            0x00,0x97,0xB9,0x2E,0xE5,0x72,0x5C,0xCB,
+            0x5D,0xCA,0xE4,0x73,0xB8,0x2F,0x01,0x96,
+            0xBA,0x2D,0x03,0x94,0x5F,0xC8,0xE6,0x71,
+            0xE7,0x70,0x5E,0xC9,0x02,0x95,0xBB,0x2C,
+            0xE3,0x74,0x5A,0xCD,0x06,0x91,0xBF,0x28,
+            0xBE,0x29,0x07,0x90,0x5B,0xCC,0xE2,0x75,
+            0x59,0xCE,0xE0,0x77,0xBC,0x2B,0x05,0x92,
+            0x04,0x93,0xBD,0x2A,0xE1,0x76,0x58,0xCF,
+            0x51,0xC6,0xE8,0x7F,0xB4,0x23,0x0D,0x9A,
+            0x0C,0x9B,0xB5,0x22,0xE9,0x7E,0x50,0xC7,
+            0xEB,0x7C,0x52,0xC5,0x0E,0x99,0xB7,0x20,
+            0xB6,0x21,0x0F,0x98,0x53,0xC4,0xEA,0x7D,
+            0xB2,0x25,0x0B,0x9C,0x57,0xC0,0xEE,0x79,
+            0xEF,0x78,0x56,0xC1,0x0A,0x9D,0xB3,0x24,
+            0x08,0x9F,0xB1,0x26,0xED,0x7A,0x54,0xC3,
+            0x55,0xC2,0xEC,0x7B,0xB0,0x27,0x09,0x9E,
+            0xA2,0x35,0x1B,0x8C,0x47,0xD0,0xFE,0x69,
+            0xFF,0x68,0x46,0xD1,0x1A,0x8D,0xA3,0x34,
+            0x18,0x8F,0xA1,0x36,0xFD,0x6A,0x44,0xD3,
+            0x45,0xD2,0xFC,0x6B,0xA0,0x37,0x19,0x8E,
+            0x41,0xD6,0xF8,0x6F,0xA4,0x33,0x1D,0x8A,
+            0x1C,0x8B,0xA5,0x32,0xF9,0x6E,0x40,0xD7,
+            0xFB,0x6C,0x42,0xD5,0x1E,0x89,0xA7,0x30,
+            0xA6,0x31,0x1F,0x88,0x43,0xD4,0xFA,0x6D,
+            0xF3,0x64,0x4A,0xDD,0x16,0x81,0xAF,0x38,
+            0xAE,0x39,0x17,0x80,0x4B,0xDC,0xF2,0x65,
+            0x49,0xDE,0xF0,0x67,0xAC,0x3B,0x15,0x82,
+            0x14,0x83,0xAD,0x3A,0xF1,0x66,0x48,0xDF,
+            0x10,0x87,0xA9,0x3E,0xF5,0x62,0x4C,0xDB,
+            0x4D,0xDA,0xF4,0x63,0xA8,0x3F,0x11,0x86,
+            0xAA,0x3D,0x13,0x84,0x4F,0xD8,0xF6,0x61,
+            0xF7,0x60,0x4E,0xD9,0x12,0x85,0xAB,0x3C };
+
+    while(Size--)
+    {
+        crc = crc ^ *Buffer++; // Apply Byte
+        crc = CrcTable[crc & 0xFF]; // One round of 8-bits
+    }
+
+    return(crc);
+}
+
+
+
+DataFrame::DataFrame(uint8_t *frame, uint8_t size)
+{
+	_frame = frame;
+	_capacity = size;
+	_frame[0] = HEADER_CHAR;
+	_frame[1] = 0;	//length of packet
+	_length = 2;
+
+}
+
+void DataFrame::Init(void)
+{
+	_frame[0] = HEADER_CHAR;
+	_frame[1] = 0;	//length of packet
+	_length = 2;
+}
+
+bool DataFrame::AddUint8(uint8_t d)
+{
+    if((_length+1) >= _capacity){
+        return false;
+    }
+
+	_frame[_length] = d;
+	_length++;
+    return true;
+}
+
+bool DataFrame::AddUint16(uint16_t d)
+{
+    if((_length+2) >= _capacity){
+        return false;
+    }
+
+    _frame[_length++] =  (d >> 8) & 0xFF;
+    _frame[_length++] =  d & 0xFF;
+
+    return true;
+}
+
+bool DataFrame::AddUint32(uint32_t d)
+{
+    if((_length+4) >= _capacity){
+        return false;
+    }
+
+    _frame[_length++] =  d & 0xFF;
+    _frame[_length++] = (d >> 8) & 0xFF;
+    _frame[_length++] = (d >> 16) & 0xFF;
+	_frame[_length++] = (d >> 24) & 0xFF;
+
+    return true;
+
+}
+
+bool DataFrame::AddInt8(int8_t d)
+{
+	return this->AddInt8((uint8_t)d);
+}
+
+bool DataFrame::AddInt16(int16_t d)
+{
+	return this->AddInt16((uint16_t)d);
+}
+
+bool DataFrame::AddInt32(int32_t d)
+{
+	return this->AddInt32((uint32_t)d);
+}
+
+bool DataFrame::AddFloat(float f)
+{
+    if((_length+4) >= _capacity){
+        return false;
+    }
+
+	 uint8_t *ptr;
+	 ptr = (unsigned char *)&f;
+
+	 _frame[_length++] = *(ptr);
+	 _frame[_length++] = *(ptr+1);
+	 _frame[_length++] = *(ptr+2);
+	 _frame[_length++] = *(ptr+3);
+
+	 return true;
+}
+
+uint8_t DataFrame::Commit(void)
+{
+	// compute _length
+	_frame[_length--] = crc8(0, _length-2, &(*(_frame+2)));
+	_frame[1] = _length;
+	// length of payload: from byte 2 to CRC byte (the last)
+	return _length;
+
+}
+
+uint8_t* DataFrame::GetFrame(void){
+	return _frame;
+}
+
+
+
+