int main(void)
{
//uint8_t last_is_zero = 1;
uint8_t i, is_active;
uint8_t adcv, adcmax, adcmin;
uint8_t score = 0, score_shifter = 0;
pin_init();
adc_init();
while(1) {
for (i=0, adcmax=0, adcmin=255; i<100; i++) {
adc_start();
while (!(ADCSRA & (1<<ADIF)));
adcv = ADCL;
if (adcv > adcmax) adcmax = adcv;
if (adcv < adcmin) adcmin = adcv;
}
rand_counter ++ ;
tx_word(adcmax - adcmin);
_delay_ms(400);
}
}
/************************************************************************
* void udp_send(WORD datalength)
* This function is called by the application to send a UDP
* packet. Values from global variables, common memory
* space and the passed data length are used.
* Optionally, a pseudo header is constructed and the UDP
* checksum calculated.
***********************************************************************/
void udp_send(WORD datalength, BYTE ephemeral)
{
WORD cssum;
ipstat.udptx++;
/* total size of IP datagram is the size of IP header */
/* plus UDP header, plus UDP data */
ip.totallen=IPSIZE+UDPHSIZE+datalength;
/* place IP header and start of trasnmit buffer */
txpos=0;
ip_header(PROTUDP);
/* use an ephemeral source port, this depends on the
* application, and must be specified when calling
* the function */
if (ephemeral) tx_word(local_port());
else tx_word(udph.dest);
/* destination port, as source port from incoming packet */
tx_word(udph.src);
/* UDP length, header length plus data length */
tx_word(UDPHSIZE+datalength);
/* UDP checksum */
tx_word(0x00);
/* UDP checksumming is specified at compile time
* if checksumming is disabled, a zero value is sent
* otherwise the pseudo header is added and checksummed
* but NOT sent */
#ifdef UPDCHECKSUM
txpos+=datalength;
tx_byte(IP1);
tx_byte(IP2);
tx_byte(IP3);
tx_byte(IP4);
tx_byte(ip.destaddr[0]);
tx_byte(ip.destaddr[1]);
tx_byte(ip.destaddr[2]);
tx_byte(ip.destaddr[3]);
tx_byte(0x00);
tx_byte(PROTUDP);
tx_word(10+udpdatal);
cssum = chksm(&txbuffer[20],8+datalength+12);
put_checksum(cssum,&txbuffer[IPSIZE+6]);
#endif
/* call SLIP to send out the packet */
slip_send(txbuffer,IPSIZE+UDPHSIZE+datalength);
}
/************************************************************************
* void tftp()
* Simple application layer server to return data
* The only functionality provided is reading, and only one 'file'.
* this function doesn't need to know anything about buffer
* positions, it simply uses functions provided by the IP layer.
***********************************************************************/
void tftp()
{
WORD opcode;
/* read the operation code */
copy_rx_word(&opcode);
/* read request */
if (opcode == TFTP_READ) {
/* check the requested filename is 'stats' */
if (rx_byte() == 's' && rx_byte() == 't' && rx_byte() == 'a' &&
rx_byte() == 't' && rx_byte() == 's' && rx_byte() == 0x00)
{
tx_word(TFTP_DATA); /* op code */
tx_word(0x0001); /* block number */
q_string(" IP Statistics \n\n",21);
q_string("Received:\t",10);
q_num(ipstat.rxpackets);
q_string("\nTransmitted:\t",14);
q_num(ipstat.txpackets);
q_string("\nDropped:\t",10);
q_num(ipstat.dropped);
q_string("\n\n",2);
}
/* requested a different file, not found */
else {
tx_word(TFTP_ERR);
tx_word(0x0001);
q_string("File Not Found.",15);
tx_byte(0x00);
}
udp_send(txpos-IPSIZE-UDPHSIZE,1);
}
/* write request, send error code and message */
else if (opcode == TFTP_WRITE) {
tx_word(TFTP_ERR);
tx_word(0x0002);
q_string("Access Violation.",17);
tx_byte(0x00);
udp_send(txpos-IPSIZE-UDPHSIZE,1);
}
}
