Cheep simple servo automated grill block active aero deployment.

[gumby79]

Video
Over the years Ive seen many struggles trying to code a R Pie or Arduino to send the pulse-width modulated signal to a servo to thermally control the opening of value of a automated Grill block. I've suggested a couple of times two people to try this as their control circuit
YouTube video
Simple automated Grill block controller

[kach22i]

Cool, I only watched the first minute or so but if I ever need to do this I'll know it's here.

Aerodynamic grill block automation proof of concept stage

[California98Civic]

Very cool, but about half of it still outside my experience and therefore not fully understood (yet).

[gumby79]

Very cool, but about half of it still outside my experience and therefore not fully understood (yet).

The servo refrences the reastat/ potentiometer ( dial adjusted resister) to know what angle the arm is. With out a signal from the raido the servo goes to defalt center x ohms if the reastat is putting out more or less than x ohms it knows to move left or right. We can tell the logic bord that the arm moved by changing the resistance it sees on the yellow wire. When it sees this change it will send the appropriate polarity to the motor to correct the position.
We have hijacked the power to an external motor. This motor moves the control rod conected to the luver. There is a 2nd refrence rod that is connected to the arm. When the refrence rod moves the arm to the correct spot the change of resistance (from the thermister) is compensated for on the reastat. Now the lodgic bord thinks the servo is centered.
Duse this help?

[teoman]

Nice way of reusing the servo controller circuit

[gumby79]

According to this chart.

I think a 2200 ohm NTC will add 2.2kohm @ 25c 77f and only 153ohm @ 100c 212f
The servo has a 5k reastat.
With power only the control bord is looking for ~2.5k ohm.
This will caus the servo to be centered/closed @77 and progressively opening to full by 212f

I tested with a 91ohm NTC to day. It worked but verry small movement on the servo to compinsate for the small change .
This NTc was 91ohm @77f and 12ohm @212mesuerd. 79 ohm change =very small light movement.in other words the slave bearly moved because of very low amperage sent.

[teoman]

Personally, i am not a great fan of this implementation.

A 1.5 usd arduino nano will get you the same results with less hassle and more freedom to do other things.

[teoman]

I am willing to fully help with the coding if one chooses to go that route.