JarJarGeek
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Joined: Tue Mar 18, 2014 11:32 am

SPI MISO / CE2

Wed Jan 27, 2016 8:22 pm

Having trouble with an addon board for a PiZero , connects to Pins 35-40 (6pins) : it's a 4tronix PZM Pi Zero Motor Shim. When I boot up PiZero - MotorB (pins35/36) starts revving at random intervals indicating something going on on those pins (very annoying) This stops though soon as I've ran a python script controlling the board / motors etc - all motors 'behave' from then on. Can't figure out what 'activities' are going on in those pins from startup - how can I find out ?? Slightly on the n00bish side on programming so be gentle :D
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joan
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Re: SPI MISO / CE2

Wed Jan 27, 2016 8:29 pm

I didn't think anything would be happening on pins 35/36 which are GPIO 19/16. They should both default to low.

Have you a link to the device you are using?

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rpdom
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Re: SPI MISO / CE2

Wed Jan 27, 2016 8:38 pm

joan wrote:I didn't think anything would be happening on pins 35/36 which are GPIO 19/16. They should both default to low.
GPIO 16 is the ACT LED on the original Pi B. I wonder if something is getting confused somewhere?

JarJarGeek
Posts: 48
Joined: Tue Mar 18, 2014 11:32 am

Re: SPI MISO / CE2

Wed Jan 27, 2016 8:48 pm

Here's the board
http://4tronix.co.uk/blog/?p=1172

Well as you said - can't think why the pins would go 'high' on boot ?? No Crons running - but soon as I run 1st Python script it stops !!
Last edited by JarJarGeek on Wed Jan 27, 2016 8:50 pm, edited 1 time in total.
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JarJarGeek
Posts: 48
Joined: Tue Mar 18, 2014 11:32 am

Re: SPI MISO / CE2

Wed Jan 27, 2016 8:49 pm

Well as you said - can't think why the pins would go 'high' on boot ?? No Crons running - but soon as I run 1st Python script it stops !!
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joan
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Re: SPI MISO / CE2

Wed Jan 27, 2016 8:54 pm

rpdom wrote:
joan wrote:I didn't think anything would be happening on pins 35/36 which are GPIO 19/16. They should both default to low.
GPIO 16 is the ACT LED on the original Pi B. I wonder if something is getting confused somewhere?
Could be I suppose with an old kernel. I just stuck a LED on my Pi Zero GPIO 16/19 and there was no visible activity during boot.

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joan
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Re: SPI MISO / CE2

Wed Jan 27, 2016 9:00 pm

All I can suggest is to make sure your kernel is up to date with sudo rpi-update. Those GPIO are actually used by the auxiliary SPI rather than the standard SPI.

JarJarGeek
Posts: 48
Joined: Tue Mar 18, 2014 11:32 am

Re: SPI MISO / CE2

Wed Jan 27, 2016 9:29 pm

Done a full update / distupgrade / rPI update - gonna try a fresh Jessie install , see if that helps
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