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Re: Raspberry Pi GPIO

Posted: Wed Feb 14, 2018 8:16 pm
by [-hh]
Take care. There are (tiny) differences between the models.
A good info is here: ... -b-and-3-b

Re: Raspberry Pi GPIO

Posted: Wed Feb 14, 2018 9:17 pm
by sphere
Thanks for that info.
Yes the Gertbot board seems also not working on rpi-3, but does on rpi-2.

But i was planning on using the Easydriver as stepper driver together with a Raspberry. First test with one motor and then a maybe second if all goes well.
I want to have a gui, and that's for me easier in LC than any other language.

It just has to do simple things, so no fancy robot arm. For repetitive actions.
Turn so many steps one way, wait a while, then back and so forth. But it has to be precise, so therefore a stepper motor is best.

I have an Odroid C2 too (very good running Android bought at, but i can't use, because it's used as movieplayer and my daughter will kill me if i used it :twisted:

Re: Raspberry Pi GPIO

Posted: Tue Feb 27, 2018 8:59 pm
by sphere

this is a very simple test stack to simply enlight a few leds, i used 1.5 Volt 20mA leds. So with 3v3 from the GPIO pins you can calculate easy which resistor you need in series with a led.
I uses the Library from Michael Doub for which i'm thankfull !
GPIO-test-led stack
(2.73 KiB) Downloaded 55 times
You can use this as a start for a simple motor-stepper driver which needs:
a PWM pulse 1 and 0 sometimes 200us.
a DIR-ection 1 or 0
ms1, ms2, ms3 so you can change the step size from Full to 16th step with combinations of 0 and 1 on each input
Eventually you could also use SLEEP and/OR ENABLE to shutoff the FET output's or the complete driver.

i bought a little driver board for 15,- euro with an A4998 ic, but you can get them for 2 euro/dollar on one of the chinese webshops, completely assembled (it's a tiny board, you can't solder the ic by hand, too little)

More next time.

Re: Raspberry Pi GPIO

Posted: Fri Oct 12, 2018 11:00 am
by sphere
well it has been a while but i finally had a bit time to check further. (after i blew up the first raspbery... :oops: )

Motor is up and running. (Filter out the mess...)
So now i want to change the repeat structure to a send in time.