FutureKit Temperature Controller

I bought this figuring it looked like a fun board to reprogram if I did not use it as a temperature controller. I don't see any source code floating around the Internet for it, so I will create some. :-)

First I thought I'd try it out in its stock form. Then I packed and moved from Oregon to California and lost the controller! I am sure it's one of my storage bins! But coding is more fun that searching bins...

Here is the data sheet for this kit.

This is an approximately 8x10cm card with a large 4 digit red LED display, 5 push buttons, relay, LED, two 3 pin headers to connect temperature sensors via 3 wire ribbon, and a 7806 6vdc regulator. (6 volt? really? There is a diode inline that drops it below the 5.5vmax for the CPU.)

Board input power is spec'ed at 12vdc, so that the 12v relay can fire. I bet it would work down to the dropout of the voltage regulator, which must be around 8 volts. High voltage input is determined by other components (like electrolytic caps) but should be fine up to about 14vdc.

The controller that I lost is an ATMega8, I am upgrading to an ATmega328P to make it more compatible with my shiny new Arduino Uno. It will drop right in. I bought a replacement along with a USB tiny ISP programmer from Sparkfun; this board has pads for a 6 pin inline header that taps into the ICSP lines so I can reprogram the controller in situ.

Sensors are one-wire DS18B20 https://www.sparkfun.com/products/245

7 segment LED display: port D0-D7 control the segments:

D0 g
D1 c
D2 d
D3 e
D4 dt
D5 b
D6 f
D7 a

port B0,C3,C4,C5 select the digit

C5 1 (numbered left to right)
C4 2
C3 3
B0 4

Push buttons are on

1 MOSI
2 MISO
3 SCK
4 D7 (shared with 7-seg segment 'a')
5 D6 (shared with 'f')

Relay is on C0

Sensor #1 is on port B1 optional sensor #2 is on port B2