[PD] digital write problem in Pduino

Derek Holzer derek at umatic.nl
Wed Oct 8 17:13:21 CEST 2008


Hi Martin,

I checked the draw of each LED, and it's about 15 mA. Should be enough 
when the Arduino can take 300 mA, but like I said the problem persists 
even when all my electronics are disconnected. And so far I've only 
tested it with one LED plugged in, trying each channel individually. 
Seems more like message collisions, as Charles mentioned.

thx,
D.

Martin Peach wrote:
> Maybe with 8 or more LEDs you are pulling too much current and the board 
> is resetting or doing flakey things because its power supply is glitching.
> Especially if you are powering it from USB.
> 
> Martin
> 
> 
> Derek Holzer wrote:
>>
>> I'm using the new Pduino 0.4beta2 and Firmata0.4beta3 with Pd-Extended
>> 0.39 and 0.40 and an Arduino NG (Atmega16 IC) to control 10 separate
>> LEDs via the Digital Write pins 2-12. Each has the possibility to blink
>> at a different speed. What I've discovered is that if I have more than 6
>> or 7 LEDs blinking at different speeds, there is cross-talk between the
>> channels causing the LEDs to blink at wrong intervals (but not in
>> unison), including the onboard one on the Arduino board on Pin 13 which
>> I'm not even sending messages to!
>>
>> I don't believe it is an electrical problem, as the wiring is quite
>> simple and I decoupled the outputs to the LEDs after the problem first
>> occurred. In fact, the problem persists even when I remove any and all
>> of my own electronics from the circuit!
>>
>> The blink interval is something in the area of 200-500 miliseconds,
>> certainly slow enough for the comport. Could it be trouble with some of
>> the objects in the [arduino] abstraction?
>>
>> Any and all suggestions appreciated, as this project needs to go out the
>> door tomorrow morning!
>> best,
>> Derek
>> -- 
>> derek holzer ::: http://www.umatic.nl ::: 
>> http://blog.myspace.com/macumbista
>> ---Oblique Strategy # 95:
>> "Is something missing?"
>>
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> 
> 
> 

-- 
derek holzer ::: http://www.umatic.nl ::: http://blog.myspace.com/macumbista
---Oblique Strategy # 186:
"Work at a different speed"




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