As I said I’m new to electronics but what I’ve read so far seems to indicate that I can use PWM to somehow control the output voltage the actuator requires, which is 0-10v I believe.
I would really appreciate it if anyone here could point me in the right direction, such as the tools I would require and how I might go about starting this project. I have a multimeter
I have the Spark shield shield so I can output 5v.
I would really appreciate anyones help as I would like to build this myself rather than paying someone to install some closed off system. I want to integrate this into my own home automation system and it would also help me control other 0-10v analogue devices.
PWM won’t work so you need to use a DAC to generate the analog output and then step this up to 10V with an amplifier. A single 2 channel op-amp can do this. The first stage applies the gain who’s output will be inverted and the second is a unity gain and inverts if back again.
A 33K resistor in series to the - input of the amp with a 100K feedback will give you 0 to -10 for 0-3.3V input. For the second stage use a 10K series and 10K feedback for a 1:1 output. You now have 0-10V on the output for 0-3.3V on the input.
This DAC board from Sparkfun should do the job for generating the 0-3.3V
Thank you so much for replying and sorry for the delay in thanking you.
OK that is the first time I’ve heard of an op-amp . I’ve just been googling a way and watching various youtube vids on how this works.
So if I get this right, you can actually increase voltage from say a 3.3v output via some form of feedback loop? wow, I never pictured that, I just assumed you had to hookup a 10v supply and some how control it’s output. Please correct me if I have got this all wrong.
Could you recommend an op-amp? I’ve seen a few on the Sparkfun site, but I just want to be sure I’m looking at the correct items. Plus I’ll prob be able to source one here locally.
I still need to get my head around the wiring of the op-amp, but I’m sure I’ll get there. Once I have all the components I’ll take various pictures for all to see. No doubt I’ll get it wrong
If you do, grab a copy of ElectroDroid for it. Really handy and has all of the OP-AMP stuff I mentioned and will show you a drawing and calculate your values for the resistors in the feedback etc.
I had a look at the ElectroDroid site and it looks pretty awesome. Shame it’s not on IOS. I’ll have a look around for something similar as that’s a great idea.
If anyone has any recommendations, please share
*Update - I’ve just purchased Circuit Playground for IOS by Adafruit, looks like it fits the bill.
I should add that to get your 10V out of the op-amp and without using what is called a rail-rail op-amp, you need to power it with at least 12V or more. 12V is a common voltage so not too difficult to come by and you can step this down to power the core at 5V.
. I’ve just been googling a way and watching various youtube vids on how this works.
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