diff options
Diffstat (limited to 'mycan.c')
| -rw-r--r-- | mycan.c | 21 |
1 files changed, 14 insertions, 7 deletions
@@ -45,6 +45,7 @@ cansend vcan0 680#00.FF.02.00.02.00.02.00 // 10+96*7+96*4+1=1067 bytes #define ENTRY_SIZE 1067 +// Convert can message to uint64_t // https://github.com/howerj/dbcc MIT static uint64_t u64_from_can_msg(const uint8_t m[8]) { return ((uint64_t)m[7] << 56) | ((uint64_t)m[6] << 48) | ((uint64_t)m[5] << 40) | ((uint64_t)m[4] << 32) @@ -59,6 +60,7 @@ int main(int argc, char **argv) struct ifreq ifr; struct can_frame frame; char *filename; + // Initialize filename to $XDG_DATA_HOME/mycan.csv. If no XDG_DATA_HOME environment variable, then initialize to $HOME/.local/share/mycan.csv { // usually ~/.local/share const char *dir=getenv("XDG_DATA_HOME"); @@ -81,12 +83,11 @@ int main(int argc, char **argv) memset(&frame, 0, sizeof(struct can_frame)); + // No need any more because I use systemd unit to autostart configure CAN network interface //system("sudo ip link set can0 type can bitrate 500000"); //system("sudo ifconfig can0 up"); - // vcan, for test - //printf("this is a can receive demo\r\n"); - // check and fix corrupted .csv file + // Check and fix corrupted .csv file due to power failure. for(FILE *fp;(fp=fopen(filename,"r"))!=NULL;) { char ch; @@ -120,6 +121,9 @@ int main(int argc, char **argv) // https://unix.stackexchange.com/questions/785686#comment1505589_785686 fflush(stdout); + // https://www.waveshare.com/wiki/RS485_CAN_HAT + // Using Linux kernel's SocketCAN + // https://docs.kernel.org/networking/can.html //1.Create socket s = socket(PF_CAN, SOCK_RAW, CAN_RAW); if (s < 0) { @@ -148,7 +152,8 @@ int main(int argc, char **argv) } //4.Define receive rules - // 24 (voltage) + 16 (temp) + // Adding masks to the socket, to only read CAN ids I want. + // 24 (voltage) + 16 (temp) can ids struct can_filter rfilter[CAN_VOLT_LEN+CAN_TEMP_LEN]; rfilter[0].can_id = 0x630; rfilter[0].can_mask = CAN_SFF_MASK; @@ -166,7 +171,7 @@ int main(int argc, char **argv) } setsockopt(s, SOL_CAN_RAW, CAN_RAW_FILTER, &rfilter, sizeof(rfilter)); - //5.Receive data and exit + //5.Receive data for(t_before=time(NULL);;) { nbytes = read(s, &frame, sizeof(frame)); @@ -175,7 +180,6 @@ int main(int argc, char **argv) uint8_t iout; FILE * fp; - // try FIFO, socket and other file types maybe better, not sure if((fp=fopen(filename,"a"))==NULL) { fprintf(stderr,"Can't open file \"%s\".\n",filename); @@ -187,14 +191,17 @@ int main(int argc, char **argv) // printf("data[%d] = %d\r\n", i, frame.data[i]); can_message_u64 = u64_from_can_msg(frame.data); t=time(NULL); + // Unpack CAN message and save to obj. This function is automatically generated using dbcc. unpack_message(&obj,frame.can_id,can_message_u64,frame.can_dlc,t); //printf("my prints:\n"); //print_message(&obj, frame.can_id, stdout); //printf("my timestamp: %u\n", t); + + // Decode CAN message and write to file, using decode functions generated automatically using dbcc. if(t>t_before) { t_before=t; - // Maybe better if concat strings and print all at once + // Maybe better if concat strings and print all at once, but it would be more complicated, I tried, see git log fprintf(fp,"%u",t); decode_can_0x630_BMS_M1_Cell_1_Voltage(&obj,&out); fprintf(fp,",%6.4f",out); |