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25 Jul 2018
Glad to announce of release of INDI Library v1.7.4 on 2018-07-25. A few drivers were added in this release as we continue to improve & stabilize existing drivers.
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TOPIC: Testing GPIOs for astroberry focuser

Testing GPIOs for astroberry focuser 4 months 1 day ago #25138

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Hi,

I am debugging my new Rpi Shield that hosts a A4988 stepper driver. When applying the focuser driver, nothing happens. So I wanted to see whether the GPIOs are sending signals to the A4988. To do so, I put a led and resistor (100 ohm) between the DIR pin and ground, likewise for the STEP pin - instead of attaching the shield to the GPIO connector. The led is showing a very low light, almost neglectible for both pins, even without attempting to run the stepper.

Does my test setup make sense, should the led be against gpio and ground, or against 3,3V?

What should I expect when running the stepper, should the led attached to the STEP only flash up when running the stepper?

Should the led attached to the DIR pin always be „on“?

Many thanks for any support, Helge

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Testing GPIOs for astroberry focuser 4 months 9 hours ago #25169

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Found the reason, the GPIOs 13, 19, and 26 are not linked to BCM2835 - bad luck...the newly designed / printed PCB became useless :(

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Testing GPIOs for astroberry focuser 3 months 4 weeks ago #25204

What do you mean by saying "GPIOs 13, 19, and 26 are not linked to BCM2835"? Did you change GPIO mapping in the driver's code? If so, did you use proper numbering? Check this (RPiGPIOPin specifically) to reconfirm this.

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Testing GPIOs for astroberry focuser 3 months 4 weeks ago #25210

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Yes, changed in the diver code, and paid attention to the numbering. According to tbis table, the mentioned GPIOs cannot bei chosen - which may explain why it did not work.

elinux.org/RPi_BCM2835_GPIOs

Is there any chance to work with these pins, still?

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Testing GPIOs for astroberry focuser 3 months 4 weeks ago #25214

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Hm...the more I read the more confused I am getting. The Pi 3 seems to host the BCM2837 (?), maybe the mentioned pins work ok, but need a different address, different to Version 2 or B+?

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Testing GPIOs for astroberry focuser 3 months 4 weeks ago #25217

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Looks like my observation was not correct, the mentioned GPIOs seem to work. Only issue remaining is that the stepper always moves clockwise, despite changing direction. Maybe something wrong with the DIR pin, hope to chase down that one soon...

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Testing GPIOs for astroberry focuser 3 months 4 weeks ago #25220

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Mission accomplished - the new „astro shield“ has been completed. It receives 12v input (see J4 connector = „hub“), which powers the stepper, and ccd, as well as the step down module, that passes back 5v for the Rpi. The circuit also hosts a shutdown / reset button for the Rpi and has a connector for the GPS module (3,3v).

The shield has been designed with Kicad (happy to share the files if of interest). And obviously leverages on the astroberry-diy-focuser.
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