After seeing AtomicMonkey's issues
here, I decided to look more into the issue.
As it turns out, some of the ADC (analog to digital converter) values are not set uniformly from the factory. They are stored in registers that can have different default values depending on the manufacturer. This caused small errors in some boards, perhaps including yours, and large errors in recent boards (Shipped mid-January and later).
I have recoded the relevant parts of the firmware, and have the following:
As you can see, I hooked up a ton of temperature sensors, 12 at first:
Displayed are the raw voltages. Converted, they are as follows:
Code:
Raw Volts deg F
0.879765 76.286
0.869990 75.38369231
0.879765 76.286
0.889541 77.1884
0.889541 77.1884
0.874878 75.83489231
0.874878 75.83489231
0.899316 78.09070769
0.889541 77.1884
0.889541 77.1884
And then, to address AtomicMonkey's problem, here is a picture of 9 thermometers and one variable resistor set at ~3.95vDC.
If you are affected by this, we offer two options, both of which can be arranged over our email account:
1.) Buy a new PIC from us. $12 shipped.
2.) Exchange PICs. Send us $6, and we will send you a new PIC. Once we get your old PIC back, we refund you.
3.) Send back your PIC, and we'll send you a new one.
All orders shipped on or after 2/19/2008 will not have this problem.