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Topic: trying to connect 2 - 32x16 LED matrixes. what hardware do i need? (Read 536 times) previous topic - next topic

sleepyjunkfoot14

i already have the 2 matrixes, but im unsure of what other hardware i need  to complete the project.

i also want to use batteries as the power source. any recommendations on which battery would work best (AA/AAA/9v)?

thanks in advance!

johnwasser

Not all 32x16 arrays of LEDs are wired the same.  Exactly what 32x16 matrix do you have?
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CrossRoads

Batteries won't last long at all.
How are the matrices wired - 32x32 configuration? 16 x 64 configuration?
Say you had 16 x 64, wired as common anode across the 16 rows, and common cathode down each of the 64 columns. Say were also set up for high current, 20mA/LED.
Then at any point in time, 16 LEDs at 20mA each could be on, drawing 320mA.
For an hour of use, that would need 320mAH of current.
Good AA batteries are ~2500mAH capacity, so you'd see less than 8 hours of use on a set of batteries.
If arranged as 32x32, that'd be 640mAH, & < 4 hrs of use.
Look into C cells, D cells, Lantern battery even (F cells), or a wallwart.
AAA, 9V - fuhgedabout it ...
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.

sleepyjunkfoot14


sleepyjunkfoot14


Batteries won't last long at all.
How are the matrices wired - 32x32 configuration? 16 x 64 configuration?
Say you had 16 x 64, wired as common anode across the 16 rows, and common cathode down each of the 64 columns. Say were also set up for high current, 20mA/LED.
Then at any point in time, 16 LEDs at 20mA each could be on, drawing 320mA.
For an hour of use, that would need 320mAH of current.
Good AA batteries are ~2500mAH capacity, so you'd see less than 8 hours of use on a set of batteries.
If arranged as 32x32, that'd be 640mAH, & < 4 hrs of use.
Look into C cells, D cells, Lantern battery even (F cells), or a wallwart.
AAA, 9V - fuhgedabout it ...


wow dude, thanks for the advice!

johnwasser


i already have the 2 matrixes, but im unsure of what other hardware i need  to complete the project.

The boards have drivers built in and are designed to be daisy-chained so you don't need any more hardware.


i also want to use batteries as the power source. any recommendations on which battery would work best (AA/AAA/9v)?


The displays are rated 0.5A Average and 1.37A Max.  For two that's 1.0 to 2.74A.  That's 5.0 to 13.7 Watts.  Multiply that by the number of hours you want to go between battery replacements.  Let's say 8 hours.  That's 40 to 109.6 Wh.  Lets call it 100 Watt Hours. 

You can string three AA Alkaline cells together in series to get 4.5V which is probably close enough..   Each string of AA cells you put in parallel adds abut 2 Ah (9 Wh) so you will need about 11 strings in parallel to be assured of lasting about 8 hours.  That's 33 cells to be replaced every 8 hours of operation.

If you switch to D cells you get 16 Ah (72 Wh) per string of three. Two strings of three should be plenty, assuming they can discharge at that rate.

Now you know why portable devices almost always use LCD displays. :)
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sleepyjunkfoot14



i already have the 2 matrixes, but im unsure of what other hardware i need  to complete the project.

The boards have drivers built in and are designed to be daisy-chained so you don't need any more hardware.


i also want to use batteries as the power source. any recommendations on which battery would work best (AA/AAA/9v)?


The displays are rated 0.5A Average and 1.37A Max.  For two that's 1.0 to 2.74A.  That's 5.0 to 13.7 Watts.  Multiply that by the number of hours you want to go between battery replacements.  Let's say 8 hours.  That's 40 to 109.6 Wh.  Lets call it 100 Watt Hours. 

You can string three AA Alkaline cells together in series to get 4.5V which is probably close enough..   Each string of AA cells you put in parallel adds abut 2 Ah (9 Wh) so you will need about 11 strings in parallel to be assured of lasting about 8 hours.  That's 33 cells to be replaced every 8 hours of operation.

If you switch to D cells you get 16 Ah (72 Wh) per string of three. Two strings of three should be plenty, assuming they can discharge at that rate.

Now you know why portable devices almost always use LCD displays. :)



Way Cool!

you have me leaning away from batteries now. would you recommend getting a EVO rev3 to accommodate a constant power supply?

johnwasser


you have me leaning away from batteries now. would you recommend getting a EVO rev3 to accommodate a constant power supply?


Near as I can tell from Google, the "EVO Rev 3" is an ASUS PC motherboard.  I don't know what that has to do with power.  Any good 12V 2A (24W) switched-mode power supply will be plenty.  EBay is full of them!  Looks like they start at around $5.
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