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16ch 12bit pwm i2c PCA9685 board

by Napalm on Wed Sep 26, 2012 3:12 am

Hi,
i am newbie to electronic stuff but normally only a programmer. English is not my native language.
I can solder. I am willing to learn ... So enough about me ;-)

Would this board https://www.adafruit.com/products/815 be good to drive a simple 8x8 led matrix.
How would i do it. Connect the annode or cathode of a 8 led row together and to one of the outputs of the board and the other side to another ... ok not easy to explain for me. but in general i know how the led matrix is wired.

I am not sure about the electronic part.
Do i need additional resistors in this wiring? Or any other electronic parts?

Should be as simple as possible. Its for me for testing purpos only.
i am more interested in the software.

regards
Mirko
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Re: 16ch 12bit pwm i2c PCA9685 board

by adafruit_support_bill on Wed Sep 26, 2012 5:10 am

We do have a "backpack" driver specifically designed for driving an 8x8 LED matrix. https://www.adafruit.com/products/870 This is the simplest way and does not require any additional parts.
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Re: 16ch 12bit pwm i2c PCA9685 board

by Napalm on Wed Sep 26, 2012 6:26 am

adafruit_support wrote:We do have a "backpack" driver specifically designed for driving an 8x8 LED matrix. https://www.adafruit.com/products/870 This is the simplest way and does not require any additional parts.


That product is really nice, BUT i guess in the end i want to use more then 4(ok, could be done with a i2c multiplexer) and, most important, i want bigger LED :-)

Those 'mini' led matrixes are nice, but i am not into mini - i like maxi more ;-)

And the next thing is, that i have the PCA9685 board at home already :-)
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Re: 16ch 12bit pwm i2c PCA9685 board

by adafruit_support_bill on Wed Sep 26, 2012 7:09 am

The matrix connections will depend on the specific matrix you are using. The PCA9685 outputs can drive up to 25mA. If you need more than that you will require external drivers. Wiring details (with and without drivers) are on page 28 of the data sheet: http://www.adafruit.com/datasheets/PCA9685.pdf For detail on how to select current limiting resistors, there is Ladyada's LED tutorial here: http://www.ladyada.net/learn/arduino/LEDs.html
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Re: 16ch 12bit pwm i2c PCA9685 board

by Napalm on Wed Sep 26, 2012 7:25 am

adafruit_support wrote:The matrix connections will depend on the specific matrix you are using. The PCA9685 outputs can drive up to 25mA. If you need more than that you will require external drivers. Wiring details (with and without drivers) are on page 28 of the data sheet: http://www.adafruit.com/datasheets/PCA9685.pdf For detail on how to select current limiting resistors, there is Ladyada's LED tutorial here: http://www.ladyada.net/learn/arduino/LEDs.html


Thank you very much. I will go and have a look at that infos.
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