I'm currently using Jrummy's Kangerade 1.1 with Chevy ulv 1.25mhz kernel. I know that those 2.2 roms currently have some problems with cpu temperatures so the CPU Temperature option never show up on setCPU program. However, I'm using the OSMonitor and under Misc, it's showing AK8973 Temperature and it seems that this temperature is more related to my CPU load.
I tried to flash P3 ultra low voltage 1.25mhz on my droid and it's actually showing CPU Temperature under both SetCPU and OSMonitor but they are always stuck at 37.9C, which is useless for creating profiles in SetCPU.
So, what exactly is this AK8973 Temperature? The best way to test how your CPU overheats at what speed is by using emulators like SNESoid imo, since it's running off only CPU I believe. I have been running it at 1.25mhz and my AK8973 Temperature has been up to over 55C which eventually crashed the emulator. So far I think 800 - 1000 is best for my droid but they still gets pretty hot running the emulator.
Anyhow, back to original question. So why is OSMonitor is able to pick up this AK8973 Temperature under CPU which seems like it's a working CPU temperature but other programs like SetCPU are not using it? I believe when I flashed P3 kernel, it shows 2 CPU temperature under OSMonitor with both AK8973 and OMAP(I think, since I went back to Chevy so it went away now), which the OMAP temperature doesn't seems to move at all.
I really like to be able to use profile in SetCPU to lower my CPU speed when over certain temperature but so far having no luck at all.
IIRC the cpu temp cant currently be monitored in froyo, this will probably be fixed soon since we now have access to the source code. The AK8973 temp is the battery temp.
Are you sure the AK8973 is the battery temperature? Because there is temperature under Battery in OSMonitor and it's showing different temperature than the AK8973. The SetCPU temperature (Not CPU temperature) is same as the temperature under battery in OSMonitor, which is different than the AK8973 one.
In case you're still interested...
The AK8973 is a magnetometer (in other words, a compass). To properly determine the phone's orientation, the chip needs to know its temperature, thus the temperature reading.