Having trouble with SERIN command and MAX6675

[emerson]

If you have an O-scope check the data out pin. That will at least let you know if it's responding.

the O-scope test checked out alright

[emerson]

I just disabled the comparators in the chip but it still won't. I even replaced the thermocouple and the MAX76675 but i get the same response. I have no idea what could be wrong with this. Any ideas?

[Bruce]

Have you tried sending the raw value received 'without modifying it' to your LCD while heating or cooling the part?

Something like: lcdout $fe, $c0, BIN16 MXtemp

Does it change when heated?

Edit: Since you're using the internal osc on this one, place Define OSCCAL_1K 1 in the top section. Not sure it that will fix it, but it will for sure affect timing.

[emerson]

Have you tried sending the raw value received 'without modifying it' to your LCD while heating or cooling the part?

Something like: lcdout $fe, $c0, BIN16 MXtemp

Does it change when heated?

Edit: Since you're using the internal osc on this one, place Define OSCCAL_1K 1 in the top section. Not sure it that will fix it, but it will for sure affect timing.

I just tried it and there is no change

[Bruce]

What's the 16-bit value shown?

[emerson]

What's the 16-bit value shown?

0000 0000 0000 0000

zeros across the board with no change to heat

[mackrackit]

Is the thermocouple a K type?
The code given in the link I gave works.
Check the hardware. Bad connections or backwards connection on the thermocouple or wrong type will cause problems.

[emerson]

Is the thermocouple a K type?
The code given in the link I gave works.
Check the hardware. Bad connections or backwards connection on the thermocouple or wrong type will cause problems.

Both the thermocouples I have are K type and are connected properly. The ground lead on the thermocouple is tied to ground as well as the negative input on the MAX6675 as demonstrated in the datasheet. I did a continuity test on all wires coming from the chip and they're all good.

[Bruce]

Did you look at the data output pin on the MAX chip with your O-scope to see if it's changing the value sent?

If you send 16 clocks, and the data line stays at ground, I would think there's a problem with the MAX IC. If you see transitions on the data line, there's something going on with the PIC side.