Fancy Thermometer

Inspiration

After being on the internet for a while someone asked me if I could help them with a project that involved something similar to a project that I had already done. The project was to be apart of a crazy fancy hard drive enclosure. I never built anything passed the breadboard but the gentlemen that the circuit was designed for did a bang up job on the final application.

Description

The circuit consists of a PIC16F819 that reads the scaled output of an LM35. The temperature scaling gives a better resolution using the PICs internal A2D. The HD activity is monitored using an OPTO and an integrator made from an opamp. The PIC averages the output of the opamp to give a 0 to 100% HD usage. Using the method the circuit can be placed on the HD led on the front of any PC case just by wiring into the front panel led. The circuit has three modes that it operates in. In mode 1 the temperature in C is displayed. In mode 2 the temperature in F is displayed. In mode 3 the percent HD usage is displayed. In mode 4 the first three modes a scrolled through in sequence. In the end the HD part of the project was not used but it is none the less a functioning part of the project.

Fancy Thermometer Prototype

This is the prototype I constructed to develop the circuits and to test the PIC code. The code was written in C to easy the joy of writing in assembly.

Fancy Thermometer Prototyped Again

Here is what the prototyped look like for the gentlemen that the circuit was designed for.

Fancy Thermometer Makes it to Circuit Card

Here is what the circuit card for the project looked like in the end.

Fancy Thermometer Display Card

Here is what the circuit card for the project looked like in the end.

Fancy Thermometer In Action

The final application for the thermometer was a really pimped out HD enclosure. I think that it looked really cool in the end.

Fancy Thermometer In Action

If you put all the pieces together this is what you get.