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[frankjb47]

Hello,

First of all, I would like to congratulate Thomas for his incredible work on AstroEQ. Simple, clean, well documented and organised material, ASCOM/EQMOD compatible...thank you for making this available.

I am currently investigating and experimenting with different hardware with the intent to develop a very accurate system for my next German Equatorial Mount. For example, possibly using the new Trinamic SilentStepStick TMC2130 for motor drivers and possibly a "real" crystal oscillator equipped Teensy 3.2 micro-controller.

What changes to the AstroEQ firmware code would have to be made in order to be "compatible" with a Teensy 3.2 board? I have not spent a lot of time investigating the code and I am wondering what kind of coding effort would be required?

Thanks in advance for your input.

Francois

[TCWORLD]

Hi Francois,

Because of the limited capabilities of the MCU that is used in the AstroEQ (8-bit AVR @16MHz), large sections of code had to be written at a very low level in order to get everything to run fast enough. As part of that most of the motor driving routines are written directly in assembly, and all of the I/O control is done using direct port manipulation. Additionally all of the timing of the motors is done using the AVR timer modules which are again initialised at the register level with little to no abstraction.

As a result it wouldn't be a trivial task to port it to a Teensy module which use 32bit ARM chips as all of the low level stuff would have to be either rewritten to suit the new processors assembly language or converted back to higher level C code.

Running on a 32bit MCU would actually help in some ways as it will reduce the calculation times as 32bit words can be processed in one go, so actually converting it back to C probably wouldn't harm it performance wise, however as I say it wouldn't be trivial to do unless you have some knowledge of assembly language and a fair amount of spare time.

Kind Regards,
Tom

[frankjb47]

Thomas,

Thanks for the quick reply.

Some time I could afford; But, not sure I have the programming skills.

Maybe a nice challenge for one of your future major upgrades...

Thanks again and best regards,

Francois

[gehelem]

Hi

I had the same question regarding SilentStep driver.
Drv8825 doesnt give good results with my setup.
So :
I've ordered a couple of tmc2100.
I've removed config pins, and moved my setup to "Drv8825+16ustep+gear change disabled" in AstroEq firmware.
It appears to work quite well, in fact much better than drv8825.
This needs real sky tests, i'll keep you informed
Gilles