Go Down

Topic: Control 20x3 Matrix powered Externally. (Read 890 times) previous topic - next topic

3rroR431

Hiii..

I'm a newbie with basic knowledge in arduino. I'd like help in changing my cars's turn signals on the side mirrors to LEDs with effects.
How can I multiplex it and will Max7219 be enough to get it done if I can use common cathode LEDs. Or using Ws2812b LEDs will be better ?

It is going to be 20x3 matrix. I need to give it effects too. So cab someone please shed some light for me .

Thank you.

Grumpy_Mike

Problem here is that a car is a difficult and hostile environment for electronics and no place for a beginner.

Their are also laws about what colour lights you can show from a car.

3rroR431

I'm showing only yellows and using this as a show car.

Grumpy_Mike

Yes in the UK yellow is illegal.

As I said the power supply is the main difficulty this might give you some options. http://forum.arduino.cc/index.php?topic=287394.0

PaulRB

#4
Feb 01, 2018, 07:55 am Last Edit: Feb 01, 2018, 07:58 am by PaulRB
I would echo the safety, legality and power supply difficulties. Those aside, you say 20x2 matrix, but what level of control do you need over these LEDs? Why 20x2? Would controlling pairs of LEDs be good enough? Or groups of 4 LEDs? What is the spec of the LEDs you had in mind? Can you post a link?

Multiplexing may not be a good option for you. Multiplexing almost always dims the LEDs. Your LEDs will need to be visible outdoors, in sunlight. You need maximum brightness.

3rroR431

I'm planning to use 5mm LEDs  with 2V forward voltage, 20mA current and 4000mcd.

https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.co.uk%2Fulk%2Fitm%2F171571350693
 

I had plans to light up each led individually so i could give effects.  But then i changed the plan to a simpler group of 4 LEDs as it saves a lot of work and decreases the complexity of the project.


As I'll be starting with the turn signals, which covers less area. But turn signals only get power when it is switched On. So shouldn't the arduino be powered and ready to read the input and process it?
And turn signals doesn't get continuous power, I should use that as inputs to make the LEDs work with external power?


Grumpy_Mike

Quote
I'm planning to use 5mm LEDs  with 2V forward voltage, 20mA current and 4000mcd.
The orange ones are the only ones that would be legal. Then they must not be constant, and you can not have any effects other than those that could be interpreted as a turn signal.

It would be much simpler to use a strip of addressable LEDs rather than individual ones.

3rroR431

@Grumpy_Mike but won't the addressable LED strip be not visible during the day ? WS2812B LEDs are only 300-400mcd. Are there brighter addressable LED?

Grumpy_Mike

#8
Feb 01, 2018, 09:03 pm Last Edit: Feb 01, 2018, 09:05 pm by Grumpy_Mike
Quote
but won't the addressable LED strip be not visible during the day
I can see the LEDs very well in daylight, in fact they are far too bright to look at directly even in daylight.

Quite honestly I don't believe those brightness figures or they are over such a tight angle that it is misleading.

3rroR431

I can see the LEDs very well in daylight, in fact they are far too bright to look at directly even in daylight.
Then I'll just go with it. But Powering them would be a problem.
I'll just try doing stuffs then try let you all know.

Go Up