CANCenter

1. CAN data frame

The data struct is as follow:

{
	ID: 'uint32',			    //text ID.
	TimeStamp: 'uint32',	//timestamp of the frame arriving, started from initialization of CAN controller
	TimeFlag: 'uint8',  	// if using timestamp, 1: use TimeStamp, 0��not use. TimeFlag and TimeStamp is available when the frame is received frame
	SendType: 'uint8',  	//send frame type. 0: normal send, 1: single send, 2: self send/receive, 3: single self send/receive, only available when
						//the frame is send frame.(when device type is EG20T-CAN, send type will be set at VCI_InitCan and it's invalid set herein
						//When set to self send/receive mode, EG20T-CAN can not receive from bus, only can receive from itself)
	RemoteFlag: 'uint8',	//remote frame flag
	ExternFlag: 'uint8',	//extended frame flag
	DataLen: 'uint8',    	//Data length(<=8), how many uint8_ts of data
	Data: refArray('uint8', 8),		  //text data
	Reserved: refArray('uint8', 3)	//reserved
}

Now we focus on the Data field (red), it has 0–64 (0-8 bytes) Data to be transmitted (length dictated by DLC field).
Our protocol is as follow:

0	1	2	3	4	5	6	7
sensorType	data index	total number	data length (1-4)Bytes	sensor data	sensor data	sensor data	sensor data

Transmit :
Data[0] : sensorType enum
Data[1] : index of sensor
Data[2] : total number of sensors in C21
Data[3] : data length(1-4)
Data[4] - [7] : data

0	1	2	3	4	5	6	7
commandID	paramter description	params	params	params	params	params	params

Receive:
Data[0] : commondID enum
Data[1] : 4-bit param number + 4-bit param data length
Data[2] - Data[7] : paramter