I am in the middle of a project and I was thinking if there is anyway to have a bargraph indicator (or even simple leds) that will display the cpu usage. As I can see this would be done with some kind of software because I dont see how it could be done otherwise. Thanks in advance
If you have an Athlon 64 with Cool 'n Quiet, you could do it all-analog. If you do, let me know and I'll elaborate.
You would need a board that supports Cool 'n Quiet and fan speed control. You would simply draw from a fan header, and with a little bit of circuitry in between, connect to an LED bargraph device. The voltage taken from the fan header would represent the current CPU load. At the nominal 12 volts, the CPU is at full load; at x voltage, the CPU is at 50%, etc. You'd need an LED bargraph driver IC, and some small discrete parts in between, but this would be an acceptable "CPU load indicator"--not a true indicator but good enough. The idea behind Cool 'n Quiet is that the processor adjusts its working frequency and voltage according to the workload. In some motherboards, the fan speed is also adjusted based on the current level of power dissipation. If the fan control circuit uses a regulator type circuit (where the supply voltage is varied but remains DC), the setup I described above would work great. If it uses a more complex PWM circuit, it would take more work.
