08M2 Temperature sensing with MCP9700

M

mrburnette

Senior Member
@Svejk:
As a personal observation, although the Picaxe Manual #2 states that the 1024 mV fixed reference cannot be used as ADC positive reference, in practice I had good results for a “climate range” (-20°C to +50°C) using that reference.
Click to expand...
I have had a similar experience with the 08M2+ using a homemade type "T" thermocouple which I describe in my blog: Thought-on-thermocouples Not sure of exactly why the documentation suggests that internal reference cannot be used but I have played around with a few 1% voltage dividers, used the AD, and compared the voltage to what I get on my Fluke DVM and everything seems to jive.

- Ray
 
Last edited:
S

Svejk

Senior Member
Actually the Manual #2 reiterates what datasheet for PIC12f1840 says about FVR. I must admit that is a bit ambigous as in 16.1.3 ADC voltage reference states FVR 2.048V and FVR 4.096V (p. 128) and in 14.0, figure 14-1 (p. 123) points the 1xADFVR to the ADC module and that matches the practice. Also is true that the datasheet is marked preliminary.
 
You must log in or register to reply here.
Top