I would say if you've got this far even with AI assistance, you have done pretty well for a first project.
OK I'll take that as a win then!
Thanks again.
Another approach is to have a look at one of the commercial units and use that to help design yours.
I'm happy with the mechanical design, it's the coding I'm stuck with. But it seems like running two Arduinos is the easiest way out, so I'll do that.
Using motors came initially about becasue for azimuth, it appeared to be far more simple to achieve what I wanted (very fine rotational adjustment and locking) with a motor, rather than a fairly complicated mechanical system.
The altitude side of things was far simpler; if the azimuth was as simple, I'd have undoubtedly stuck with manual adjustments for both axes, and retained the 9V DC tracking drive.
Thanks.
Although I don;t see any NEED for two boards, it will reduce the board to motor wire length, but then you may want two power packs. Under no condition use a 9v smoke alarm battery. Under no condition power a motor from an MCU or MPU board; always use a (big) battery. I use the following for my astrophotography work. Some for dew heaters, one as my main camera battery using the DC adaptor and a smaller ANKER power pack to power the NOMAD (Rotator). If you want Amazon links, just let me know.
Use Arduino NANO, either one or two and look for the tutorial on the forum regarding state machine and/or doing multiple things at once. NO delay() in your code please. You may want to consider desoldering the LED on the NANO to both save power and your night vision.
Thanks.
I was considering using my emergency car battery booster for the power supply. I'm not sure whether the 5V 2.1A USB output would be any good for my application?
But that's a future part to the story I guess.
When I've tried all this out to my satisfaction, my intention was to solder all the wiring permanently, and mount the boards in printed boxes, so the LEDs shouldn't be a problem.
@sonofcy I think you mentioned the Arduino Cookbook earlier?
Is it the one by Michael Margolis, with the rabbit on the cover?
Thanks.
Here's a sample of two steppers on one Arduino for a different project:
It isn't modified for two separate speed trim controls, but it does 2 axis, adjustable speed jogging.
My dad had an RA tracker built upon a 555 and a little synchronous motor. It had a trim pot to adjust the basic tracking rate, and then he had a dongle built out of a pipe body with a DPDT switch in it to add modify the 555 timer circuitry to slew faster or slower for framing the picture.
Yes, that's it.
That is powerful enough for the board, but not for the motors. Here is some motor info, but when the time comes I recommend a Pololu driver that is MOSFET type as they are WAAAAY more efficient and cool. Do a seperate project to learn the best way to use them for you.
There are two reasons to get rid of the LEDs, the second being they use a fair bit of power. I would get rid of them.
OK, but I've still got the 12V output which, if it can crank several cold engines into life from a dead battery, surely must be capable of powering some small motors for a couple of hours?
It says it's a 24 Watt-hour Li-ion battery.
Thanks.
I really appreciate your help, but I have to be honest - as a complete beginner I wouldn't know how to interpret the code, or indeed if it would apply to my project.
In my simplistic mind, my application is simpler, because the two motors being jogged (which work fine) do not need simultaneous speed control.
It's the third motor that needs speed control as a one-off setting. It doesn't need jogging. This also works, but again in isolation when run with its own code.
I think before trying to decipher code, I need to understand exactly why my code isn't working. I understand it's something to do with the processor being overloaded with a continuous stream of inputs and outputs, and the time function of the speed control being disrupted by this process, hence it's not responding properly to the analogue input from the potentiometer?
Again - I appreciate everyone's input, but I think you are hugely overestimating my familiarity with Arduino code. Getting the three motors to work as I wanted was actually very easy, and I understand the prnciples of how they are working and being controlled...but that's about it.
Thanks.
Given that you only need the slew occasionally during the night, then no problem. The tracking will likely use more.
Highly unlikely, some of these boards run at 240 million instructions per second which is lots.
It's not really even slew - it's just occasionally making tiny adjustments to two axes to finely centre a target.
The tracking motor will run continuously though, at a very low speed.
However, when not being used, the motors need to hold position to prevent accidental movement (at least the azimuth axis does - the altitude has the leadscrew that cannot be back-driven).
OK, so I'm pretty much where I started then - which is at a loss as to how to understand the situation, let alone solve it.
Keep in mind the minimum holding power is 2W but can be as high as 10W. Is that 24Wh battery still looking good enough?
Well, it depends on how many watts the motors actually pull. If it's 2W, then yes, if it's 10 watts, then no.
Again...I don't know.
End of the day I can plug it all into the mains, but I'd rather not have trailing cables.