//the main function waits for all the bytes in the STK500v2 packet,
//then sends for processing in the above functions
int main(void)
{
unsigned char ch;
unsigned char prev_ch=0;
//unsigned char chr_nl=0; //unused
unsigned char msgparsestate;
unsigned char cksum=0;
unsigned char seqnum=0;
int msglen=0;
int i=0;
uart_init();
//wd_init();
LED_INIT;
LED_OFF;
//sei(); //enable AVR interrupts
msgparsestate=MSG_IDLE;
// default values:
CONFIG_PARAM_SW_MINOR=D_CONFIG_PARAM_SW_MINOR;
CONFIG_PARAM_SW_MAJOR=D_CONFIG_PARAM_SW_MAJOR;
while(1){
if (msgparsestate==MSG_IDLE){
ch=uart_getchar(1);
}else{
ch=uart_getchar(0); //getting extra bytes, use timeout
}
// parse message according to appl. note AVR068 table 3-1:
if (msgparsestate==MSG_IDLE && ch == MESSAGE_START){
msgparsestate=MSG_WAIT_SEQNUM;
cksum = ch^0;
continue;
}
if (msgparsestate==MSG_WAIT_SEQNUM){
seqnum=ch;
cksum^=ch;
msgparsestate=MSG_WAIT_SIZE1;
continue;
}
if (msgparsestate==MSG_WAIT_SIZE1){
cksum^=ch;
msglen=ch<<8;
msgparsestate=MSG_WAIT_SIZE2;
continue;
}
if (msgparsestate==MSG_WAIT_SIZE2){
cksum^=ch;
msglen|=ch;
msgparsestate=MSG_WAIT_TOKEN;
continue;
}
if (msgparsestate==MSG_WAIT_TOKEN){
cksum^=ch;
if (ch==TOKEN){
msgparsestate=MSG_WAIT_MSG;
i=0;
}else{
msgparsestate=MSG_IDLE;
}
continue;
}
if (msgparsestate==MSG_WAIT_MSG && i<msglen && i<280){
cksum^=ch;
msg_buf[i]=ch;
i++;
wdt_reset(); //wd_kick();
if (i==msglen){
msgparsestate=MSG_WAIT_CKSUM;
}
continue;
}
if (msgparsestate==MSG_WAIT_CKSUM){
if (ch==cksum && msglen > 0){
// message correct, process it
wdt_reset(); //wd_kick();
programcmd(seqnum);
}else{
msg_buf[0] = ANSWER_CKSUM_ERROR;
msg_buf[1] = STATUS_CKSUM_ERROR;
transmit_answer(seqnum,2);
}
// no continue here, set state=MSG_IDLE
}
msgparsestate=MSG_IDLE;
msglen=0;
seqnum=0;
prev_ch=0;
i=0;
}
return(0);
}
int main(void)
{
unsigned char ch;
unsigned char prev_ch=0;
unsigned char chr_nl=0;
unsigned char msgparsestate;
unsigned char cksum=0;
unsigned char seqnum=0;
int msglen=0;
int i=0;
uart_init();
wd_init();
LED_INIT;
LED_OFF;
sei();
msgparsestate=MSG_IDLE;
// default values:
CONFIG_PARAM_SW_MINOR=D_CONFIG_PARAM_SW_MINOR;
CONFIG_PARAM_SW_MAJOR=D_CONFIG_PARAM_SW_MAJOR;
if (eeprom_read_byte((uint8_t *)EEPROM_MAGIC) == 20){
// ok magic number matches accept values
CONFIG_PARAM_SW_MINOR=eeprom_read_byte(EEPROM_MINOR);
CONFIG_PARAM_SW_MAJOR=eeprom_read_byte(EEPROM_MAJOR);
}
while(1){
if (msgparsestate==MSG_IDLE){
ch=uart_getchar(1);
}else{
ch=uart_getchar(0);
}
// parse message according to appl. note AVR068 table 3-1:
if (msgparsestate==MSG_IDLE && ch == MESSAGE_START){
msgparsestate=MSG_WAIT_SEQNUM;
cksum = ch^0;
continue;
}
// The special avrusb500 terminal mode.
// Just connect a serial terminal and press enter twice.
// Both Windows and Linux send normally \r (=0xd) as the
// only line end character. It is however possible to configure
// \r\n as line end in some serial terminals. Therefore we
// must handle it.
if (msgparsestate==MSG_IDLE && (ch == '\r'||ch == '\n')){
i++;
if(chr_nl ==0 && ch=='\n' && prev_ch== '\r'){
// terminal sends \r\n for new line
chr_nl=1;
}
prev_ch=ch;
if (chr_nl){
// wait for \r\n \r\n
if (i==4){
terminalmode(1);
i=0;
}
}else{
// Linux wait for \n\n
if (i==2){
terminalmode(0);
i=0;
}
}
continue;
}
if (msgparsestate==MSG_WAIT_SEQNUM){
seqnum=ch;
cksum^=ch;
msgparsestate=MSG_WAIT_SIZE1;
continue;
}
if (msgparsestate==MSG_WAIT_SIZE1){
cksum^=ch;
msglen=ch<<8;
msgparsestate=MSG_WAIT_SIZE2;
continue;
}
if (msgparsestate==MSG_WAIT_SIZE2){
cksum^=ch;
msglen|=ch;
msgparsestate=MSG_WAIT_TOKEN;
continue;
}
if (msgparsestate==MSG_WAIT_TOKEN){
cksum^=ch;
if (ch==TOKEN){
msgparsestate=MSG_WAIT_MSG;
i=0;
}else{
msgparsestate=MSG_IDLE;
}
continue;
}
if (msgparsestate==MSG_WAIT_MSG && i<msglen && i<280){
cksum^=ch;
msg_buf[i]=ch;
i++;
wdt_reset(); //wd_kick();
if (i==msglen){
msgparsestate=MSG_WAIT_CKSUM;
}
continue;
}
if (msgparsestate==MSG_WAIT_CKSUM){
if (ch==cksum && msglen > 0){
// message correct, process it
wdt_reset(); //wd_kick();
programcmd(seqnum);
}else{
msg_buf[0] = ANSWER_CKSUM_ERROR;
msg_buf[1] = STATUS_CKSUM_ERROR;
transmit_answer(seqnum,2);
}
// no continue here, set state=MSG_IDLE
}
msgparsestate=MSG_IDLE;
msglen=0;
seqnum=0;
prev_ch=0;
i=0;
}
return(0);
}
