Hi vla , could you do a quick test on your test panel using pin 40. Mine seems to be going wild.

Thank you
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Hi Luke,
Tested (serial driver on pin #40, 10-step LED bar), no problems.
Thank you vlad, is it possible for me to use pin 12 and 13 for 2 led bars that aren't daisy chained?
Of course,
You can "connect" any number of DM13A drivers to any free pin and use any number of LED bars.
Great thank you, I think it would be super helpful if you can make a post on how to use external power 5v, vled. I know you have written a bit about it, but a picture tutorial would be amazing. Different forms as it is one of the most important aspects to a stable set up as I have noticed


Yes, there are some  issues with powering different devices in such complex system, that need to be clarified.

Currently I'm assembling new test platform (along with many other  "to-do"-s) and hope I will find some time soon to describe all aspects of system powering.

For your LED bars, 7-segment displays you can use a power supply that has sufficient current limit.  This limit depends on the total number
of LEDs in your system and what current resistor you have set for DM13A.

For example if your resistor is 2k, every lightened LED consumes 30 mA (it can be too bright for your cockpit), if this  resistor is 3 k - the current is limited by 20 mA (that gives you 400mA for 20 LEDs lit simultaneously).

Plus, every 7-segment display gives you from  20 to 200mA (depending on brightness and number of digits).

In many cases, for a system with 20-30 LEDs and 3-4 7-segment displays using the USB power may be quite enough. Else, you need to find more powerful source (some 5V "wall adapter" ) and use it as V
led (connecting "-" with GND).

In case of LCDs  it's more specific, they can be more caprice when power load  is changing during system work.


Great can't wait for your post.

Am I allowed to use a external breadbox with 5v power chip? Use its + and -  and use the pin outputs on the mega?  Or does the breadbox need to be connected to the mega somehow?