Added a crc mpeg2 python test script using crcchecker, also added a test c file for transmitdata using some test values.

Author: zelongzhang

crcmpeg2Test.py

@@ -0,0 +1,10 @@
+import crccheck
+
+
+crcmpeg = crccheck.crc.Crc32Mpeg2()
+
+
+if __name__ == "__main__":
+	data = bytearray.fromhex('0000102120423063408450a560c670e79129a14ab16bc18cd1ade1cef1ef123132732252')
+	crchex = crcmpeg.calchex(data)
+	print('0x'+crchex)

test_new_message.c

@@ -0,0 +1,124 @@
+#include <stdio.h>
+#include <stdint.h>
+#include <stdlib.h>
+
+#define IMU_SERIAL_MSG_SIZE (36)
+#define START_FLAG (0xF0)
+#define END_FLAG (0XF0)
+#define F0_ESCAPE (0xF1F2)
+#define F1_ESCAPE (0xF1F3)
+
+static const int8_t IMU_HEADER_BYTE = 0x31;
+
+uint8_t* Encode(uint8_t* message, int length);
+void writeInt32ToArray(uint8_t* array, int startIndex, int32_t value);
+
+int main()
+{
+	//use dummy data to test if encoding and construction of final send buffer are correct.
+	int32_t accelX = 0x1234F0F1;
+	int32_t accelY = 0xF1F2F3F1;
+	int32_t accelZ = 0x98765432;
+	int32_t gyroX = 0xF0F0F0F0;
+	int32_t gyroY = 0xF1F1F1F1;
+	int32_t gyroZ = 0xF3F2F1F0;
+	int32_t magnetoX = 0xABCDEF71;
+	int32_t magnetoY = 8;
+	int32_t magnetoZ = 0xF0;
+	uint32_t crc = 0xABCD1234;
+
+	uint8_t message[IMU_SERIAL_MSG_SIZE] = { 0 };
+	int messageindex = 0;
+	
+	writeInt32ToArray(message, messageindex, accelX); 		messageindex += 4;
+	writeInt32ToArray(message, messageindex, accelY); 		messageindex += 4;
+	writeInt32ToArray(message, messageindex, accelZ); 		messageindex += 4;
+	writeInt32ToArray(message, messageindex, gyroX); 		messageindex += 4;
+	writeInt32ToArray(message, messageindex, gyroY); 		messageindex += 4;
+	writeInt32ToArray(message, messageindex, gyroZ); 		messageindex += 4;
+	writeInt32ToArray(message, messageindex, magnetoX); 	messageindex += 4;
+	writeInt32ToArray(message, messageindex, magnetoY); 	messageindex += 4;
+	writeInt32ToArray(message, messageindex, magnetoZ); 	messageindex += 4;
+
+	for (int n = 0; n < IMU_SERIAL_MSG_SIZE; n++)
+	{
+		if (n % 4 == 0)
+			printf("\noriginal message at [%d to %d]:", n, n + 4);
+		printf("%x", message[n]);
+	}
+	
+	uint8_t* encoded_message = Encode(message, IMU_SERIAL_MSG_SIZE);
+
+	int encoded_length = encoded_message[0];
+	int buffer_length = encoded_length + 10;
+	for (int m = 1; m < buffer_length; m++)
+		{
+			if ((m-1) % 4 == 0)
+				printf("\nencoded message at [%d to %d]:", m-1, m + 4 -1);
+			printf("%x", encoded_message[m]);
+		}
+
+	
+	uint8_t* buffer = malloc(buffer_length * sizeof(uint8_t));
+	buffer[0] = START_FLAG;
+	buffer[1] = IMU_HEADER_BYTE;
+	for (int i = 0; i < encoded_length; i++)
+	{
+		buffer[i] = encoded_message[i];
+	}
+	buffer[buffer_length - 1] = END_FLAG;
+
+	for (int o = 1; o < buffer_length; o++)
+	{
+		if (o % 4 == 0)
+			printf("\nfinal  buffer at [%d to %d]:", o , o + 4);
+		printf("%x", buffer[o]);
+	}
+	
+
+	return 0;
+}
+
+uint8_t* Encode(uint8_t* message, int length)
+{
+	uint8_t* buffer = malloc(2 * sizeof(uint8_t) * length);
+	int bufferindex = 0;
+	for (int i = 0; i < length; i++)
+	{
+		//printf("Encoding %x ...\n", message[i]);
+		if (message[i] == 0xF0)
+		{
+			buffer[1+bufferindex++] = 0xF0;
+			buffer[1+bufferindex++] = 0xF1;
+		}
+		else if (message[i] == 0xF1)
+		{
+			buffer[1+bufferindex++] = 0xF1;
+			buffer[1+bufferindex++] = 0xF2;
+		}
+		else
+		{
+			buffer[1+bufferindex++] = message[i];
+		}
+	}
+	buffer[0] = bufferindex+1;
+	printf("\n\nFinal buffer size = %d\n", buffer[0]);
+	return buffer;
+}
+
+void writeInt32ToArray(uint8_t* array, int startIndex, int32_t value)
+{
+	//printf("Writing %d ...\n", value);
+
+	//printf("Writing %d to index+0\n", (value >> 24) & 0xFF);
+	array[startIndex + 0] = (value >> 24) & 0xFF;
+
+	//printf("Writing %d to index+1\n", (value >> 16) & 0xFF);
+	array[startIndex + 1] = (value >> 16) & 0xFF;
+
+	//printf("Writing %d to index+2\n", (value >> 8) & 0xFF);
+	array[startIndex + 2] = (value >> 8) & 0xFF;
+
+	//printf("Writing %d to index+3\n", value & 0xFF);
+	array[startIndex + 3] = (uint8_t)(value & 0xFF);
+}