why does it show junk?

basicstampede

Hello.

I have a program that reads temperature.· Then I want to display it on a serial LCD, but I get junk.

SUB Get_Temperature
· HIGH resetpetp
· SHIFTOUT DQ, Clock, LSBFIRST, RdTmp
· SHIFTIN DQ, Clock, LSBPRE, tempIn
· SHIFTIN DQ, Clock, LSBPRE, tempInS\1
· LOW resetpetp
· RETURN

The temp I want to show is in tempIn which is Byte.

Then I convert the tempIn to two numbers and send to LCD as follows.·
· temp10 = tempIn / 10
· temp1 = tempIn // 10
··
· LCDdata = ClearLCD
· SER_OUT
· LCDdata = temp10
· SER_OUT
··LCDdata = temp1
· SER_OUT

Subprogram to show on LCD is tested and working when sending characters.

Do I need to convert it to·ASCII character before sending it to serial LCD?· How do you do that in SX/B?

Thanks.·

PJAllen

Yes, you have to convert the number to the ASCII character.· A "0" is $30, a "1" is $31,... a "9" is $39.

JonnyMac

The LCD wants ASCII characters and you're sending their decimal values. You need to do something like this:

temp10 = tempIn / 10
temp01 = __REMAINDER ' this saves a lot of code versus using //

LCDdata = temp10 + "0" ' convert to ASCII
SER_OUT
LCDdata = temp01 + "0"
SER_OUT

RobotWorkshop

You should also make sure you have a stable clock source (resonator, crystal oscillator, etc) to ensure the serial data is transmitted correctly. Some people have tried to use the internal clock source and it isn't accurate enough for reliable serial data. That would also produce garbage. Just something to keep in mind.

Robert

Bean

basicstampede,
It is much easier to troubleshoot if you post the entire program. Otherwise we are just guessing...

Bean.

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