bratwurst wrote:OK so last weekend my buddies went out on our long-planned camping trip, and I couldn't because my truck was stuck in the shop, getting a new tail section on the transmission. The truck has been off the road for 6 weeks now.
Rather than pout about it, I got back to work on the AC install (without a truck). I need to get the control panel going before the installation is completed at a local AC shop. If you've looked at the vintage air control panels, they are designed to blend in with muscle car and hot rod panels - not really what I want in my G.
So the plan is to hack apart a W202 climate control unit and use that to control the Vintage Air unit. I don't need to make a full climate control system - initially I am going to keep the software simple and focus on "manual" controls. I am using an Arduino as the microcontroller; it needs to drive 3 power lines for the blower, operate a servo for the heater valve and one for setting the vent positions, and it also needs at a minimum 1 temperature sensor to monitor the evaporator core for freezing. To support future "climate control" features I also will install a temperature sensor in the cabin and either outside the truck or in the cooling system (not sure which is more important yet).
This weekend, I got the difficult part done; driving the LCD. Making a "raw" LCD panel display anything useful is not as simple as connecting a couple of wires. To do this you need to create a bunch of waveforms and depending on the phasing between them, the LCD segments will appear. I'll save the gory details, but let me just say I learnt a lot.
Below are two pictures, the control panel, and one of the wave forms I managed to successfully generate with the Arduino. Possibly only interesting to electronics geeks, but hey, I'm proud of what I've accomplished!
Very nice vintage HP T&M equipment you have there!