Is Arduino efficient enough for GoTo on Dobson?

[Vroobel]

Hi all, 

I read several times that people make Arduino controlled GoTo system for their telescopes. Are the telescopes sat on equatorial or any Alt-Aż mounts? 

I used the Arduino at first , but that became too weak when I tried to apply complicated equations taken from an "Astronomical Algorithms" books written by Jean Meeus. I realised I have to replace the Arduino with a Raspberry Pi, that works well with the equations. 

Is here anybody successfuly applied the GoTo with Arduino and Dobson mount? 

Tomasz 

[hughgilhespie]

Hi Tomasz, I am sure that you can use make a successful Arduino based go-to system but you are using an 8 bit processor running at 16 MHz clock speed. If you ask it to do lots of floating point double precision calculations it will do them but not very quickly. There are other choices from the extended Arduino family that would be better suited. I am thinking of a Teensy 3.6. Has a 32 bit processor and runs at 180 MHz (I think) and has a built-in floating point processor but you can still use the Arduino IDE for programming which keeps things simple. The Teensy's use ARM processors and they will work with almost all the standard Arduino libraries plus they have some Teensy specific libraries that may be very useful, for instance a very high speed stepper driver library.

HTH.

Regards, Hugh

[Vroobel]

Thank you for so wide information. As you can see in picture below, I moved towards the Raspberry Pi and only Arduino shield and stepper motor controllers left on board. The Raspberry is not only more efficient, that has hundred times more abilities, so I think that gives me plenty of different ways to develop my telescope. 

I am interested if someone else stuck with single/double precision of Arduino and its speed, as you perfectly described that above. Apparently we have same experience... 

I think it's very easy to adapt the Arduino as the GoTo controller if you have equatorial mount, because the calculations are nothing in comparison to transformation of coordinates from Ra/Dec to Az/Alt in real time, that's I am working with, having superb results. 

I regret I didn't know it earlier, I could save time and money... 

[Dave_D]

Have you tried looking at a microcontroller like an ESP32? it's a 32bit 180Mhz (i think) controller and has a huge lead on performance over ATMega based chips

[Vroobel]

I'm not so good as a chip programmer. Now I feel good with Python on RPi. Thanks a lot, anyway!

[Vroobel]

BTW, is the ESP32 so easy to programming like the Arduino? Has it own programming environment?

[Stub Mandrel]

I've done a GOTO with an arduino - well on an AVR which is the chip used on an arduino).

I used AVR assembler which is ideal for doing stuff like this quickly as you can choose the precision you want and hard-code things like sine tables which makes everything much faster than using floating point trig routines!

It was for an EQ mount. I suspect that goto and tracking for a dob are not that much more processor demanding, especially if you are guiding which shoudl enable you to eliminate any residual errors.

I have wondered if I could convert my Dob, although a tilting base might be a better way.