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635 programming

BlancMange

New member
Hey guys, me again :rolleyes:

just another question...

is it possible to program the LCD using its on board memory / bootrom to do the following scenario:

im looking at getting a phase change unit built by kayl (if you have heard of him), just a basic one without a controller....

im wondering, can i use the 635 + scab so when i press the tick on it, it will boot the compressor (relay on a GPIO or somthing) and then once the temperature reaches the desired value (-35 deg cel for example) it will then boot the pc and once windows is loaded act like a normal CF lcd with CC2.


so heres the events i was thinking of:
press Tick
Relay engages (using a flipflop to toggle the relay or somthing like that, so the LCD just needs to pulse the GPIO once)
compressor turns on
desired temperature is reached
LCD boots PC.
Windows loads, and CC2 initializes the LCD


then, as another question on top... if that is possible.... if i press the tick to start the cycle, and i want to stop it (e.g. turn the compressor off before it reaches the desired temp) by pressing the X, it just cancels the cycle and turns the relay off.


is that even remotely possible.... as otherwise i will have to turn the compressor on manually, watch a external temp sensor, then boot the pc manually....

thanks in advance
-matt
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Heffo

New member
Here are my thoughts (since customizing a new 635 would be rather costly for a single unit, and I doubt you could get fully functional firmware source from CF to do it yourself)

Use the ATX functionality of the 635, but instead of connecting it to the mainboard, connect it to a small PCB with a simple PIC (or some other microcontroller), programmed to interface with a temp sensor, the relay for the compressor and the Power switch pins on the mainboard.

The temp sensor will be the fun part, the DOW Temp sensors CFontz use for the SCAB have an operating range of -55°c to +125°c but is only accurate to 0.5°c in the -10°c to +85°c range. but may still be good enough for your application.

Basically, when it works. The Tick on the 635 will pulse a pin on the microcontroller which then fires up the relay, turning on the compressor, and then starts monitoring the DOW temp sensor. Once it hits a stable -35°c (or whatever you want), the micro then pulses the power switch on the mainboard starting the PC. Then if you hit the 'X' on the 635, the pulse from that tells the micro to shut off the PC (if it's on) and turn the compressor back off.

Robert Heffernan
 
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