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how many chips can a chipchuck chuck?
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how many chips can a chipchuck chuck?

by jim on Thu Oct 07, 2010 6:28 pm

my project is to use six arduino pins to switch sequentially between 6 different attiny 2313, powered with the 5v onboard using 6 transistors (4401) with 100 ohm resistors.
each tiny powers 8 LED briefly one tiny after the other.

i think i am failing to provide enough power to the tinys.
i guess my problem is the resistor i used with my transistor.
i thought the 100 ohm tested good on my breadboard this morning.
my test was faulty.

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Re: how many chips can a chipchuck chuck?

by cstratton on Thu Oct 07, 2010 9:53 pm

Its usually better to control an enable line than a device power line, especially if you can figure out how to inhibit the clock.

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Re: how many chips can a chipchuck chuck?

by Entropy on Fri Oct 08, 2010 1:39 pm

I agree - is there any free digital I/O on the Tinys?
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Re: how many chips can a chipchuck chuck?

by uhe on Mon Oct 11, 2010 9:05 am

I also agree with cstratton. Every pin on PORTB can react to an external interrupt plus the INT0/1 irqs on PB2/3 (easier to use that the irqs on PORTB;). With theese pins you can address the tiny you want to use.

If you have power concerns, you could en/disable the sleepmode of the tiny depending on the pin/irq state.
If you use the tinys just as a LED driver, there are better options (and theese are chainable and have chip select lines ;)!
AFAIK you should calculate the base-resistor of a transistor and not *test* which works.
Btw what is a chipchuck?

As for your power concerns:
What makes you think that you did not provide enough power to the tinys? A actual error description would help alot e.g. what do you expect and what happens?
Which 5v onboard do you use and how many mA can you draw from that?
When you know that you can calculate you power consumption and compare what you need and what you have.

HTH
"I have not failed. I've just found 10,000 ways that won't work." - Thomas Edison
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Please be positive and constructive with your questions and comments.