A temperature display for our spa using a 14M2

[saunj]

I had to make a replacement for the thermostat on our spa, and I used a PICAXE for it - reported on Sep 12, 2011. As a byproduct, it reports using SERTXD. Our spa does have a Radio Shack digital thermometer but it is not easy to read, and you have to be in the spa. This has a big, bright LED readout and it sits high on a swivel so it can be read from the house too. It automatically shows the ambient temperature when the spa is off.
I'm not proud of the design because it uses a lot of ICs, which was a lot of work, but, hey, I'm retired so what's my time worth?
You might be interested if you need to multiplex common-anode LEDs, or if you use SERIN, which is tricky.
Read about it in my website: http://www.projects.worsleyassociates.com

 

[westaust55]

Can you please post your full schematic here for completeness.

you make the comment:

I'm not proud of the design because it uses a lot of ICs . . .

Looking at the schematic via the link provided, a strip down the left side with the terminal identification onmissing/obliterated.
Also where and what are the other IC's? The posted schematic only shows a 14M2
The TempDisplay.bas program file includes reference to 74HC595 shift register chips and an LM335 temp sensor.

 

[saunj]

Full Schematic

Can you please post your full schematic here for completeness.

you make the comment:

Looking at the schematic via the link provided, a strip down the left side with the terminal identification onmissing/obliterated.
Also where and what are the other IC's? The posted schematic only shows a 14M2
The TempDisplay.bas program file includes reference to 74HC595 shift register chips and an LM335 temp sensor.

Thank you for your interest.
Unfortunately the full schematic exceeds the forum permitted size.
Did you look at all of the pages in my web site? There are 4 pages of schematics. Keep looking, I will make a block diagram to help sort out the interconnections and post that.
The terminals you could not make out? Were they the Display Module? It is a Kingsbright and only of interest if you are using it. The display was cut from a big board sold by The Electronic Goldmine for $3.75, but its no longer offered.
I make my schematic diagrams using RFFLOW, but its file type is not allowed in the forum.