That isn’t correct. I have since revised the design to move the inversion function from the opamp to the flight controller - just select “reverse” in the servo output. It makes the circuit MUCH simpler as can be seen. I added the C2 and C3 bypass caps which frankly I’m not even using at this point. I tested it on the mower and it works using my Kakute flight controller under RC control.
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This is what one channel looks like. I built 2 identical ones; one for right and one for left motor.
If enough interest in these I could get jlpcb to send some prefab ones.
And a demo video https://youtu.be/nsSyc3Nw4wA
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So here is the updated-updated version…
I also subscribed to your Youtube Channel…
FYI: I am slowly creating a Github repository of the mower project and will give credit…
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Kinda Interested…
I am interested. I think a need for an optically coupled PWM signal converted to 0-5v will come up again in converting these battery operated electric mowers. I don’t know how expensive they will be but, I will chip in an purchase some.
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Here is the progress so far. Just hooked it up to the RC receiver, but it only output the full voltage amount, via volt meter. Also, I am interested in the PCBs.
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I’m interested in this concept and had a few minutes the other night. Just in case anybody wants it, here is the artwork to make your own PCB from the schematic listed above. Also a link to how I make my PCBs. You may need to resize the image to the correct size listed depending on what program you use to print the artwork.
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Very nice. I’ve done some homemade PCBs before with success. Frankly a circuit this simple just takes a couple minutes to handwire so not so worth it to me.
Note 2 of these modules are needed. But adding to the complexity, at least in my case, is I wanted to make so that the mower is 100% operational as original when the autopilot is off. This required the additional 8 channel relay board of which I am using 7 channels.
If I were to try to make a PCB for these mowers I’d start with the 8 channel relay board and add a couple of these DACs and a nice harness to plug and play to the original connectors. The whole thing could be installed in just a few minutes.
Here’s my messy implementation. I used 2 CAT9 cables (the blue cables) to connect to the drive circuits.
Also I added a couple LEDs to the DACs so I can visually see the PWM output from the FC.
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It won’t work connected to an RC receiver. It needs the flight controller to translate to full PWM (Brushed Bipolar)
I am interested in six boards please cberkeley@yahoo.com
AH, that might explain why… Was also wondering if it was the Amazon ICs…
Thanks!
BTW the authentic opamps arrived today from Microchip. Much smoother and consistent response as expected. $4 for 5 but $11 shipping.
I like the picture of your electronics. It’s looks very functional and well built and designed. I like it!
It’s just a parameter you have to set.
What box did you us and where did you get it? Also how did you mount it?
I used a waterproof plastic enclosure with a see thru cover from amazon. I fabricated a mount using bed frame angle iron.