Afternoon all,
Apologies if this question is in the wrong format or in the wrong place, if this is the case, please flag and I'll change it or take it elsewhere.
I am using a development board to send a temperature reading to an LCD panel and I am really struggling to comprehend as to why the temperature at the moment that the program is run isn't being printed onto my LCD. A lot of the code is from framework given to me and is correct as far as I can tell.
My question stems from these functions:
uch get_temp()
{
int i;
DQ_HIGH();
reset(); //reset,wait for 18b20 responsion
write_byte(0XCC); //ignore ROM matching
write_byte(0X44); //send temperature convert command
for(i=20;i>0;i--)
{
//display(); //call some display function,insure the time of convert temperature
}
reset(); //reset again,wait for 18b20 responsion
write_byte(0XCC); //ignore ROM matching
write_byte(0XBE); //send read temperature command
TLV=read_byte(); //read temperature low byte
THV=read_byte(); //read temperature high byte
DQ_HIGH(); //release general line
TZ=(TLV>>4)|(THV<<4)&0X3f; //temperature integer
TX=TLV<<4; //temperature decimal
if(TZ>100)
{
TZ/100;
} //not display hundred bit
ge=TZ%10; //integer Entries bit
shi=TZ/10; //integer ten bit
wd=0;
if (TX & 0x80)
wd=wd+5000;
if (TX & 0x40)
wd=wd+2500;
if (TX & 0x20)
wd=wd+1250;
if (TX & 0x10)
wd=wd+625; //hereinbefore four instructions are turn decimal into BCD code
shifen=wd/1000; //ten cent bit
baifen=(wd%1000)/100; //hundred cent bit
qianfen=(wd%100)/10; //thousand cent bit
wanfen=wd%10; //myriad cent bit
NOP();
return TZ;
}
I have modified this function so that it should return the temperature integer (unsigned char TZ)
This function is then called here:
void Init_lcd(void)
{
ADCON1 = 0x07; //required setting of analog to digital
uch Temp;
TRISD = 0x00;
TRISA1 = 0;
TRISA2 = 0;
TRISA3 = 0;
writeCommand(0x0f);
writeCommand(0x38); //set to two line mode
clearDisplay();
writeString("MAIN MENU");
Temp = get_temp();
writeString(Temp);
writeCommand(0xC0); //change cursor line
}
It isn't printing anything after "MAIN MENU", which obviously means I'm doing something wrong. I can provide further clarification/code on request.
I should probably mention that I am NOT only simply looking for an answer of "paste this in and it'll work". Any feedback in which I understand my mistake and how to fix it is greatly appreciated.
Thanks in advance!
EDIT:
A few people are asking about my writing functions so for further clarification I'll paste them here:
void writeChar(unsigned char ch)
{
lcd = ch;
RS = 1;
RW =0;
E = 1;
lcdDelay();
E=0;
}
void writeString(char *stringToLcd)
{
while(*stringToLcd > 0)
{
writeChar(*stringToLcd++);
}
}
Temp
is an unsigned char
uch Temp;
//...
Temp = get_temp();
writeString(Temp);
So, using writeString()
will produce undefined results.
You should use write()
instead (depending on the library you're using).
But you probably want to convert the return value of get_temp()
to an ASCII string first, and display that using writeString()
.
Update:
void writeString(char *stringToLcd)
This function needs a char*
, so you can't provide a single uch
.
You need to convert Temp
to a string first, using itoa()
for example.