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Micro:bit servo control
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Micro:bit servo control

by Ailstyn on Thu Sep 21, 2017 12:47 pm

Hello, I trying to use the towerpro micro servos from adafruit (https://www.adafruit.com/product/169) with the BBC Micro:bit. So far, the most I've gotten out of it is a soft clicking noise and zero movement. I've tried using an external power source for the servo, but that did even less (eg: nothing). I can't see any reason they shouldn't be compatible, but I am stuck.

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Re: Micro:bit servo control

by adafruit_support_carter on Thu Sep 21, 2017 12:52 pm

This guide uses a servo and might be useful:
https://learn.adafruit.com/micro-bit-ra ... troduction
See the info there helps.

If not, post a photo of your setup showing how you've connected the servo to the micro:bit.

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Re: Micro:bit servo control

by Ailstyn on Thu Sep 21, 2017 1:39 pm

It's a little hard to see in the photo, but it is hooked up brown-GND, orange-3V, yellow-0.
IMG_20170921_132405.jpg
IMG_20170921_132405.jpg (260.39 KiB) Viewed 175 times

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Re: Micro:bit servo control

by Ailstyn on Thu Sep 21, 2017 1:45 pm

Sorry, should have mentioned: yes, I followed the instructions and that setup is the same as far as I can see. It produces the quiet clicking noise I mentioned, but no movement.

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Re: Micro:bit servo control

by adafruit_support_carter on Thu Sep 21, 2017 1:47 pm

That seems OK. What does your program look like?

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Re: Micro:bit servo control

by Ailstyn on Thu Sep 21, 2017 1:53 pm

Pressing either button makes the LEDs display the correct pattern, and the nonstop clicking.
screenshot.jpg
screenshot.jpg (503.5 KiB) Viewed 169 times

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Re: Micro:bit servo control

by jerryn on Thu Sep 21, 2017 2:02 pm

Just an observation. Is is possible that your white alligator clip is also contacting the pin next to P0 (P4).
Good luck!

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Re: Micro:bit servo control

by adafruit_support_carter on Thu Sep 21, 2017 2:20 pm

How are you powering the micro:bit? Can you power it via battery?

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Re: Micro:bit servo control

by Ailstyn on Thu Sep 21, 2017 2:23 pm

When I power it from the 2xAA pack for the micro:bit it does the nonstop clicking, if I power the board through the USB cable it clicks once, and then I think it resets because the screen goes black, shows the "on start" screen, and the computer re-mounts it.

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Re: Micro:bit servo control

by adafruit_support_carter on Thu Sep 21, 2017 2:33 pm

if I power the board through the USB cable it clicks once, and then I think it resets because the screen goes black, shows the "on start" screen, and the computer re-mounts it.

I'm getting the same behavior. Not sure what's causing this but probably related to the servo drawing power.

When I power it from the 2xAA pack for the micro:bit it does the nonstop clicking

Batteries are working OK for me. Are yours fresh? And are they alkaline or rechargeable? (I'm using alkaline)

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Re: Micro:bit servo control

by Ailstyn on Thu Sep 21, 2017 2:50 pm

I'm using the batteries the micro:bit shipped with, which are actually triple-A not double, and do not say what kind they are. The battery pack itself says "only carbon-zinc or alkaline", so I assume it's one of those. When the board is powered I put a voltmeter to it and it outputs a constant 2.8V. I'll try picking up some fresh alkaline batteries tonight and see if they work better.

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Re: Micro:bit servo control

by adafruit_support_carter on Thu Sep 21, 2017 3:02 pm

I'm using the batteries the micro:bit shipped with

Hmmm. Same here. And I'm also using that exact same servo. Go over your wiring to make sure it's all solid. I'm using these:
https://www.adafruit.com/product/3255
straight into the servo connector, so it's a little cleaner.

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Re: Micro:bit servo control

by Ailstyn on Thu Sep 21, 2017 4:32 pm

I bought some fresh AAA's and it's working for me now, which is a nice neat solution. I did try powering with external batteries but my wiring must have been bunk, I'll have to try it again sometime just so I know. For now the crisis is averted, thanks for the help!

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Please be positive and constructive with your questions and comments.