bms/Application/app/protocol.c

#include "protocol.h"
#include <string.h>
#include "bsp/uart.h"
static uint16_t _check_sum(uint8_t*data,uint16_t size);
static uart_enum_t current_uart = SHARK_UART0;
/*
 * 调用 protocol_send_xxx 接口的时候，需要注意需要多分配can_head_t 大小的内存，并且
 * 需要offset掉can_head_t 大小, 这样设计的原因是避免多次拷贝
*/
void protocol_send_bms_info(protocol_head_t *head){
	can_head_t *can = (can_head_t *)(((uint8_t *)head) - sizeof(can_head_t));
	can->can_addr = 0x42;
	can->size = head->size;
	head->checksum = 0;
	head->checksum = _check_sum((uint8_t *)head, head->size);

	shark_uart_write_frame(current_uart, (uint8_t *)can, sizeof(can_head_t) + head->size);
}


void protocol_send_debug_info(uint8_t dest, uint8_t *data, int size){
	can_head_t *can = (can_head_t *)(data - sizeof(can_head_t));
	can->can_addr = dest;
	can->size = size;

	shark_uart_write_frame(current_uart, (uint8_t *)can, sizeof(can_head_t) + size);
}

void protocol_recv_frame(uart_enum_t uart_no, uint8_t *data, int len){
	current_uart = uart_no;
	if (len < sizeof(can_head_t)){
		return;
	}
	can_head_t *can_head = (can_head_t *)data;
	if (can_head->can_addr == 0x45){ //pc sent

	}else {
		len -= sizeof(can_head_t);
		if (len <sizeof(protocol_head_t)){
			return;
		}
		protocol_head_t *head = (protocol_head_t *)(data + sizeof(can_head_t)) ;
		if (len != head->size) {
			return;
		}
		uint16_t check_sum_rx = head->checksum;
		head->checksum = 0;
		if (check_sum_rx != _check_sum(data, head->size)){
			return;
		}
	}

}

static uint16_t _check_sum(uint8_t*data,uint16_t size)
{
	uint32_t checksum;
	if((NULL == data)||(0 == size)){
		return 0;
	}
	checksum = 0;
	while(size>1) {
		checksum += *(uint16_t*)data;
		data += 2;
		size -= 2;
	}
	if(size>0) {
		checksum += *data;
	}

	while(checksum>>16) {
		checksum = (checksum&0xFFFF)+(checksum>>16);
	}
	return (uint16_t)~checksum;
}