Thread: Analog Output Voltage

Is voltage output something you guys would like? I thought that controlling fan speeds and things like that was what people wanted?

Speak now or forever hold your peace.

Originally Posted by doogieb

Hi there, I'm looking at potentially controlling fan speed and temperature in my car via the PC, similar to what is discussed in this thread

From what I can see, my 1990 BMW E32 730i uses variable resistors for the temperature and fan speed selection.

Is there a simple way to interface with this via the fusion brain with the digital outputs (I'm guessing deciding on the number of possible steps and building a resistor network which translates into these steps), or would it be achievable with this add on board, or is there something else obvious I'm missing?

This is doable. You can create an R2/R network if you want, but you will need an amplifier in there too so that the value doesnt change depending on the load! It is pretty simple and something like a 741 should work. We will eventually have this board available for sale all together if you would rather purchase all together than build the analogue output yourself.

i think analog outputs would be pretty cool. At the moment, I dont have a use for em, but you never know..

Very interested in analog outs here, the obvious climate controls use was my main motivator, but this silly little CB project idea thread I started would probably use them as well. Is this going to be built with controlling a stepper-motor type of servo in mind as well? can you see a way, without a servo pot, to use analog output to vary a resistance setting in another circuit? Two hands up for analog out. Many vehicles control the heater's blend door with such a servo.
I think it would probably take more than 5A to replicate the lexus parallel park trick, wouldn't it? But I'm fine with starting small.
I really would like to see the analog out option made into a reality!

Digipot?

How is analog output going to work for skinning and in the program? am I going to be able to use the signal going out for indication? as a percent? engineering units?

For instance, my fan speed indicator needs to know what's going out to the fan....
I guess I could just use a resistor network and a crap load of DO's but that would not be very cool.

Is output voltage going to be adjustable or are you...that's the 4 range thing isn't it?
I can't think of anything other than 0 to 5 or 0 to 12 that I need, maybe 0 to -5 and 0 to -12?

5 amps isn't going to be enough to drive fans, so another amplifier will have to be put to use then.

How much money are you looking at for say a 40A version? I was looking to drive my blower motor with a R/2R DAC and an amp that I could adjust with pots for minimum fan speed and max fan speed, I figured that would make it so others could follow, and implement in their vehicles. If you made a high output version that would sure be nice.

What's the alternative to 10 (or whatever) speed fan control; 10 outputs and relays with possibly a separate brain. (Yuk! - So much for small electronics). All of those who want to have a smoother fan acceleration with your climate control use of the brain, feel free to chime in here, and show some demand. I guess it's all about the cost though.

I'm thinking that 40 amps enough to cover the range of most vehicles blower motors.

4 outputs and 32 steps? wow. my digital math must be screwy, it happens.

Edit:Actually, I'd like to know how that works. Maybe I'm just missing something simple, but 1111=15 (16, including 0) and 11111=31 (32, including 0) steps. This would help me with my skinning.