Ahh yes, I didn't notice one was saying 60 degrees and the other saying 80 degrees.

I'd say our values are "close enough" for sure!

 

Tim,

what I've done here can easily be copied. From your earlier posts I can see that you already own an Arduino Mega. My little gizmo is Arduino powered. I just did away with all the external circuitry that isn't necessary for the task at hand and wired it all up on a n experimental PC board.

We have two analog inputs with bias resistors (100 Ohms in this case). They read the values coming off the sensors. Then there are two PWM outputs that power small MOSFETs. Those drive the gauges. One of the gauges was not easily coerced into behaving, so I needed to add some more passive elements on that output, but overall it's a fairly simple thing. Below is the schematic as an image. I can email you the files and Arduino program if you'd like.

ST


Schematic


board


the real thing


The linearization curve for the water temp gauge (PW over Analog in)

 

Very nice! Also you have bigger ***** than me soldering an AVR, I usually use a socket.