Temperature with the LM34C

[StoneColdFuzzy]

I didn't think that I changed Bruce's code, except for direct serial, but it's good to get more than one set of eyes on it. I'll keep checking connections; it's got to be the hardware. Thanks again y'all!

~ Dave

[Bruce]

Dave,

Are you getting anything from DEBUG, or is it just not showing any change in temp?

If DEBUG is showing a fixed value even when the temp changes, the sensor may be wired
wrong.

If you're using a boot-loader;

1. It most likely has the USART enabled, so you may need to disable the USART to use the
USART TX pin with DEBUG.

2. If your serial connection is through a MAX232 inverter, then you need to use mode 0
with DEBUG for non-inverted serial.

3. Most boot-loaders don't allow you to change config settings, so embedding them in your
code isn't necessary. And the loader might have some config settings different than what
you expect.

[StoneColdFuzzy]

Hi Bruce, no, I'm getting no DEBUG from the board.

I'm connected to the serial port through a 1k resistor which is why I have debug mode at 1.

How do I disable USART? TXSTA=0?

[Bruce]

RCSTA = 0 should do it. You just need to clear RCSTA.7 (SPEN) to disable the USART.

With a direct connection, make sure you have a common ground connection between your
board & the PC serial port.

[StoneColdFuzzy]

No change when USART disabled.

I'm pretty sure that it's a connection. I tried the code straight up except for debug mode at 1 and received 7 lines of temperature in Hyper Terminal, then it stopped.

Going back to double check everything.

~ Dave

[Bruce]

Darrel most likely hit the nail on the head. Sounds like some odd hardware problem, or a
bad connection.

Troubleshoot things one-at-a-time, and just setup a simple loop shooting serial data to
your PC serial port until you get the serial com thing working.

If it goes-like-splat, then you know there's a bad connection - or maybe even a problem
with your PC serial port.

Note: It might even be a problem with the PIC itself if the A/D is foo-bar. The ADCIN library
function is a blocking type with;

adcinloop
btfsc ADCON0, GO_DONE ; Wait for conversion to complete
goto adcinloop

If ADCON0, GO_DONE never gets cleared, it's a sit & spin function call...;o}

[StoneColdFuzzy]

Darrel most likely hit the nail on the head. Sounds like some odd hardware problem, or a
bad connection.

Troubleshoot things one-at-a-time, and just setup a simple loop shooting serial data to
your PC serial port until you get the serial com thing working.

If it goes-like-splat, then you know there's a bad connection - or maybe even a problem
with your PC serial port.

I have no idea how to begin setting up a loop like this.

Note: It might even be a problem with the PIC itself if the A/D is foo-bar. The ADCIN library
function is a blocking type with;

adcinloop
btfsc ADCON0, GO_DONE ; Wait for conversion to complete
goto adcinloop

If ADCON0, GO_DONE never gets cleared, it's a sit & spin function call...;o}

I have no idea what the above means either.

~ Dave