4 Channel Thermostat using PID loops

[malc-c]

Hi Mike,

The menu's as they stand are fairly basic. If the option button is pressed the main menu is displayed.

LCDOUT $FE,2,"Main Menu"
lcdout $FE, $C0, "Select Option"

IF Option = 1 THEN lcdout $FE, $D4, "Set Time and Date  "
if option = 2 then lcdout $FE, $D4, "Set Night Period   "
if option = 3 then lcdout $FE, $D4, "Set Normal Temps   "
if option = 4 then lcdout $FE, $D4, "Set Lighting Period"
if option = 5 then lcdout $FE, $D4, "Run                "

Depending what state you leave the option button set to the LCD display reads

Main Menu
Select Option

Set Time and Date

The normal temp sub menu simply displays the A/D from the four pots.

The sub menu for the lighting period simply shows the time which gets changed by the +/- buttons so you can set the on time and then repeated for the off time (for each viv).

If I get chance I'll take some photo's of each menu and post them up at a later stage.

[malc-c]

Guys,

Normally when strip boarding I build as I build up the board from the schematic as I go along, and often test each section, ie get the LCD working, then the sensors, then the switches, then the RTC etc. However this time I used an application to design the board and having followed it found that the board contains an error somewhere as the LCD doesn't work. I'm no longer able to edit the post to remove the image so..

DO NOT USE THAT IMAGE

[mackrackit]

Sounds like one more reason not to use simulators and such.

I always thought, WOW!!!
Those folks that write simulators must really be good. Able to anticipate all variables and all....
Yeah right....

[Mike, K8LH]

Hi Malcom,

Thank you for the brief description of the user interface. It sounds very easy and very intuitive.

A couple more questions, please? (1) Do you "lock out" the pots' to prevent someone from accidentally bumping them and changing the settings? (2) Could you use a single pot' to adjust the four zones, one zone at a time?

Cheerful regards, Mike

[malc-c]

Hi Mike,

In the current format I use 4 pots, one for each channel, and having selected the manual temp setting option from the menu can set all 4 channels to whatever temps I need which are picked up when exiting out of the menu and back to the live screen. You could re-write the code to use one pot and cycle through each channel if you wished, however I preferred to use 4 pots.

No the pots are not locked as such, but you do need to select the menu option to adjust them. Once they have been set and the menu returns to the live screen you can twiddle the knobs as much as you like and it won't change the values - this does prevent accidental changing of the set temperatures.

I'm still working on taking the project from the development board to a working prototype, and once I've done that and had it running for a while I'll update the project with the final release of the code and some project notes.

[malc-c]

Well I've just completed the two boards in the MKII prototype, and was pleased to find that when I plugged the mains lead in there was no bang, no smoke but the thing actually powered up and displayed temperatures on all 4 inputs with the LEDs flashing away indicating the outputs were also running.

All that's needed now is to make up the sensor leads properly, fit the correct 3 core cable for the supply and hook up the output board to the controller via 7 way cable - then install it and monitor how it performs...

I'll post up a few more photo's as the installation progresses.

[malc-c]

Well, seven months after the initial post, and with the welcome assistance from DT to develop the code, the hardware has finally been completed and tested. All that remains is to remove the old commercial ON/OFF stats and hook the heaters and light up to this new unit.

I might look at having some PCB's made up as I've been asked if I could build a unit by other reptile keepers... and who knows, there may even be a market for such a device....