Author Topic: $50 Robot - Adding 6 more pins.  (Read 1570 times)

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Offline pomprockerTopic starter

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$50 Robot - Adding 6 more pins.
« on: September 04, 2008, 11:32:14 AM »
So last night I soldered in the header pins to break out PB0, PB6, PB7, PD5, PD6, PD7.



I hooked the power up to the unregulated source, as I figure they'd be better used for more servos.

Does anyone abject to that? Would they be better as regulated for sensors?

I know someone said that the PB0/ICP Capture pin is good to hook up a sensor to it.

What about power issues? Would I need more than a 6V NiMH battery if say my mega168 was 'loaded' to the max with sensors and actuators?

I know Admin said he did this for one of his robots. Any words of wisdom?

« Last Edit: September 04, 2008, 11:34:11 AM by pomprocker »

Offline dsheller

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Re: $50 Robot - Adding 6 more pins.
« Reply #1 on: September 04, 2008, 01:06:21 PM »
I'd say it's fine, but seeing as building a robot isn't like dusting crops... boy... you should consider whether or not your battery has the capacity to support that many servos if they're all running at once. Check what your batteries discharge rate is... usually expressed as <x> C where x is a value and C is correlated to the mAh rating of your battery. So if the battery discharges at 1C it will last for one hour.

Offline Webbot

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Re: $50 Robot - Adding 6 more pins.
« Reply #2 on: September 04, 2008, 03:42:57 PM »
It all depends on whether you want more input or more outputs.

PB1 and PB2 are a key resource - the hardware PWM outputs. So if you want to use these to drive servos they need to use the unregulated source, but if you are using them to drive an H-Bridge then they need to use the regulated source.

If you are like me, then I often don't know what I will be connecting. Thats why I created my own board with each I/O pin having two headers: one for the unregulated supply, one for the regulated. Now I can drive lots of outputs or have lots of sensors.
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Offline pomprockerTopic starter

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Re: $50 Robot - Adding 6 more pins.
« Reply #3 on: September 04, 2008, 04:02:46 PM »
Yeah I didnt break out PB1 and PB2.

I remember the thread about that have dual header pins

 


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