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Topic: flip flop it or 4051 it? (Read 3 times) previous topic - next topic

Paranemertes

lol that was a tad bit non sequitur.

I am thinking about the 74HC595. but i think it can only provide 20mA of current, so if i want to use all three leds at one time... can someone confirm that?
http://download.siliconexpert.com/pdfs/2005/03/06/semi_ap/2/phi/shift%20registers/74hc_hct595.pdf

Thoughts?
oh i found a pretty good how to for this shift register on the main site:
http://www.arduino.cc/en/Tutorial/ShiftOut
"It's Dr. Evil. I didn't spend six years in Evil Medical School to be called 'mister,' thank you very much."

CrossRoads

Here's the start of the matrix. The anodes would be driven by a '574 wired as I discussed, the cathode by transistors.
This diagram used '374s (had them on hand) and the SPI pins to drive them.
Designing & building electrical circuits for over 25 years. Check out the ATMega1284P based Bobuino and other '328P & '1284P creations & offerings at  www.crossroadsfencing.com/BobuinoRev17.
Arduino for Teens available at Amazon.com.

NI$HANT

What MM of LED are you using?
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Paranemertes

@NI$HANT, they are 5mm rgb common ground LEDs.

@CrossRoads, those pics are helpful, never would have thought to use a flip flop like that. What are your thoughts on the 595 for my purposes?
"It's Dr. Evil. I didn't spend six years in Evil Medical School to be called 'mister,' thank you very much."

CrossRoads

My thoughts are: they are rated as 6mA output. LEDs typically require a current of 20mA to achieve rated brightness.
Use a part that is rated to provide 20mA, vs one that has a protection circuit that may allow 20mA.
74AC574 will do that that.
Designing & building electrical circuits for over 25 years. Check out the ATMega1284P based Bobuino and other '328P & '1284P creations & offerings at  www.crossroadsfencing.com/BobuinoRev17.
Arduino for Teens available at Amazon.com.

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