Hi All
I'm using a couple of maxim DS18B20's and an ethershield to create a basic xml page showing the current temperature from the two sensors. I decided to add an LCD unit (16x2, supported by the LiquidCrystal lib) to show the temperature as well, but I just can't get it to work.
I've stripped out all the code that changes what the LCD is showing and am just having it display a string on each line during setup (working) and then changing this to be a different string in the loop (not working, no update happens). I then went back to basics and created a new prog which uses just the lcd code, everything else pulled out. This works, so the LCD unit itself is ok.
Even stranger, when I visit the web page for the first time after the prog is reset, the "-" in the "Sensor 1 - " string is removed from the LCD and never comes back.
The code isn't very clean and probably doesn't follow best practice, but compiles, and I can't see what's wrong with it. I'd be very grateful if anyone has any ideas!
#include <OneWire.h>
#include <string.h>
#include "etherShield.h"
#include <LiquidCrystal.h>
OneWire ds(3);
byte addresses[2][8];
byte i;
int x = 0;
LiquidCrystal lcd(12, 11, 4, 5, 6, 7);
char temp_strings[2][10];
static uint8_t mymac[6] = {0x54,0x55,0x58,0x10,0x00,0x24};
static uint8_t myip[4] = {192,168,10,15};
static char baseurl[]="http://192.168.10.15/";
static uint16_t mywwwport = 80;
#define BUFFER_SIZE 500
static uint8_t buf[BUFFER_SIZE+1];
#define STR_BUFFER_SIZE 22
static char strbuf[STR_BUFFER_SIZE+1];
EtherShield es=EtherShield();
uint16_t print_webpage(uint8_t *buf);
int8_t analyse_cmd(char *str);
void setup() {
Serial.begin(9600);
byte addr[8];
byte done = 0;
lcd.begin(16, 2);
lcd.print("Sensor 1 - ");
lcd.setCursor(0, 1);
lcd.print("Sensor 2 - ");
/*initialize enc28j60*/
es.ES_enc28j60Init(mymac);
es.ES_enc28j60clkout(2); // change clkout from 6.25MHz to 12.5MHz
delay(10);
/* Magjack leds configuration, see enc28j60 datasheet, page 11 */
// LEDA=green LEDB=yellow
//
// 0x880 is PHLCON LEDB=on, LEDA=on
// enc28j60PhyWrite(PHLCON,0b0000 1000 1000 00 00);
es.ES_enc28j60PhyWrite(PHLCON,0x880);
delay(500);
es.ES_enc28j60PhyWrite(PHLCON,0x990);
delay(500);
es.ES_enc28j60PhyWrite(PHLCON,0x880);
delay(500);
es.ES_enc28j60PhyWrite(PHLCON,0x990);
delay(500);
es.ES_enc28j60PhyWrite(PHLCON,0x476);
delay(100);
//init the ethernet/ip layer:
es.ES_init_ip_arp_udp_tcp(mymac,myip,80);
Serial.println("Searching for OneWire Devices....");
while ( !done )
{
if ( ds.search(addr) != 1)
{
Serial.print("No more addresses.\n");
ds.reset_search();
done = 1;
return;
}
else
{
Serial.print("Found ");
printAddress(addr);
}
if ( OneWire::crc8( addr, 7) != addr[7]) {
Serial.println(", but CRC is not valid!");
return;
}
if ( addr[0] != 0x28) {
Serial.println(", but Device is not a DS18B20 family device!");
return;
}
memcpy(addresses[x], addr, 8);
x++;
Serial.println(" - DS18B20 device accepted.");
}
}
void loop(void){
uint16_t plen, dat_p;
int8_t cmd;
Serial.println("got here");
lcd.setCursor(0,0);
lcd.print("Sensor1 - 12.34");
lcd.setCursor(0,1);
lcd.print("Sensor2 - 56.78");
Serial.println("got here too");
plen = es.ES_enc28j60PacketReceive(BUFFER_SIZE, buf);
/*plen will ne unequal to zero if there is a valid packet (without crc error) */
if(plen!=0){
// arp is broadcast if unknown but a host may also verify the mac address by sending it to a unicast address.
if(es.ES_eth_type_is_arp_and_my_ip(buf,plen)){
es.ES_make_arp_answer_from_request(buf);
return;
}
// check if ip packets are for us:
if(es.ES_eth_type_is_ip_and_my_ip(buf,plen)==0){
return;
}
if(buf[IP_PROTO_P]==IP_PROTO_ICMP_V && buf[ICMP_TYPE_P]==ICMP_TYPE_ECHOREQUEST_V){
es.ES_make_echo_reply_from_request(buf,plen);
return;
}
// tcp port www start, compare only the lower byte
if (buf[IP_PROTO_P]==IP_PROTO_TCP_V&&buf[TCP_DST_PORT_H_P]==0&&buf[TCP_DST_PORT_L_P]==mywwwport){
if (buf[TCP_FLAGS_P] & TCP_FLAGS_SYN_V){
es.ES_make_tcp_synack_from_syn(buf); // make_tcp_synack_from_syn does already send the syn,ack
return;
}
if (buf[TCP_FLAGS_P] & TCP_FLAGS_ACK_V){
es.ES_init_len_info(buf); // init some data structures
dat_p=es.ES_get_tcp_data_pointer();
if (dat_p==0){ // we can possibly have no data, just ack:
if (buf[TCP_FLAGS_P] & TCP_FLAGS_FIN_V){
es.ES_make_tcp_ack_from_any(buf);
}
return;
}
if (strncmp("GET ",(char *)&(buf[dat_p]),4)!=0){
plen=es.ES_fill_tcp_data_p(buf,0,PSTR("HTTP/1.0 200 OK\r\nContent-Type: text/html\r\n\r\n<h1>200 OK</h1>"));
goto SENDTCP;
}
if (strncmp("/ ",(char *)&(buf[dat_p+4]),2)==0){
plen=print_webpage(buf);
goto SENDTCP;
}
cmd=analyse_cmd((char *)&(buf[dat_p+5]));
if (cmd==1){
plen=print_webpage(buf);
}
SENDTCP: es.ES_make_tcp_ack_from_any(buf); // send ack for http get
es.ES_make_tcp_ack_with_data(buf,plen); // send data
}
}
}
}
uint8_t find_key_val(char *str,char *key)
{
uint8_t found=0;
uint8_t i=0;
char *kp;
kp=key;
while(*str && *str!=' ' && found==0){
if (*str == *kp){
kp++;
if (*kp == '\0'){
str++;
kp=key;
if (*str == '='){
found=1;
}
}
}else{
kp=key;
}
str++;
}
if (found==1){
// copy the value to a buffer and terminate it with '\0'
while(*str && *str!=' ' && *str!='&' && i<STR_BUFFER_SIZE){
strbuf[i]=*str;
i++;
str++;
}
strbuf[i]='\0';
}
return(found);
}
int8_t analyse_cmd(char *str)
{
int8_t r=-1;
if (find_key_val(str,"cmd")){
if (*strbuf < 0x3a && *strbuf > 0x2f){
// is a ASCII number, return it
r=(*strbuf-0x30);
}
}
return r;
}
void getOneWireTempFromAddr(byte address[8], int sensorno){
byte present = 0;
byte data[12];
float temperature = 0.0;
byte ms = 0;
byte ls = 0;
int j;
ds.reset();
ds.select(address);
ds.write(0x44);
delay(1000);
present = ds.reset();
ds.select(address);
ds.write(0xBE); // Read Scratchpad
for ( i = 0; i < 9; i++) { // we need 9 bytes
data[i] = ds.read();
if(i == 0) ls = data[i];
if(i == 1) ms = data[i];
}
//process ms bit
for(j = 7; j > 4; j--){
if((ms & 1) == 1) temperature = temperature + pow(2, (11 - j));
ms = ms >> 1;
}
//process ls bit
for(j = 7; j >= 0; j--){
if((ls & 1) == 1) temperature = temperature + pow(2, (3 - j));
ls = ls >> 1;
}
//turn temp float into char
int tempdec = (temperature - (int)temperature) * 100;
if(tempdec < 10){
sprintf(temp_strings[sensorno], "%0d.0%d", int(temperature), tempdec);
}else{
sprintf(temp_strings[sensorno], "%0d.%d", int(temperature), tempdec);
}
Serial.println(temp_strings[sensorno]);
//Serial.println(temp);
//temp = "21.34";
}
void printAddress(byte address[8]){
for( i = 1; i < 7; i++)
{
Serial.print(address[i], HEX);
if(i != 6) Serial.print(":");
}
}
uint16_t print_webpage(uint8_t *buf){
getOneWireTempFromAddr(addresses[0], 0);
getOneWireTempFromAddr(addresses[1], 1);
uint16_t plen;
plen=es.ES_fill_tcp_data_p(buf,0,PSTR("HTTP/1.0 200 OK\r\nContent-Type: text/xml\r\n\r\n"));
plen=es.ES_fill_tcp_data_p(buf,plen,PSTR("<?xml version=\"1.0\" encoding=\"ASCII\" standalone=\"yes\"?>"));
plen=es.ES_fill_tcp_data_p(buf,plen,PSTR("<tempsensors>"));
for(int z = 0; z < 2; z++){
plen=es.ES_fill_tcp_data_p(buf,plen,PSTR("<sensor><name>Sensor"));
plen=es.ES_fill_tcp_data_p(buf,plen,PSTR("</name><temp>"));
i=0;
while (temp_strings[z][i]) {
buf[TCP_CHECKSUM_L_P+3+plen]=temp_strings[z][i++];
plen++;
}
plen=es.ES_fill_tcp_data_p(buf,plen,PSTR("</temp></sensor>"));
}
plen=es.ES_fill_tcp_data_p(buf,plen,PSTR("</tempsensors>"));
return(plen);
}
Many thanks!
EDIT: the "got here" and "got here too" in the loop are continuously appearing on the serial console, so it is looping through the code.
