Pages: [1]   Go Down
Author Topic: 16 segment LED with 74LS154  (Read 2072 times)
0 Members and 1 Guest are viewing this topic.
0
Offline Offline
Newbie
*
Karma: 0
Posts: 41
Arduino rocks
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

I have 12 of 16 segments LEDs. I would like to use all of them. Can we use 74ls154 (4 line to 16 decoder) with 16 segments LED. Each segments will have thier own transistor. Will that work?

Reid
Logged

Massachusetts, USA
Offline Offline
Tesla Member
***
Karma: 201
Posts: 8684
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

You have 192 segments.  If you use two of the 74ls154 decoders (one for digits, one for segments) you will only be able to light one segment at a time.  That means each LED is lit only 0.52% of the time, max.  You also have to do updates at 11,520 segments per second to get a 60 Hz update rate.

You would probably be better off using a 16-bit shift register for segments and the 74ls154 only for the digit drive.  Then you can have each digit lit 1/12th of the time (8.3%) and only 720 digits per second to get 60 Hz refresh rate.
Logged

Send Bitcoin tips to: 1L3CTDoTgrXNA5WyF77uWqt4gUdye9mezN
Send Litecoin tips to : LVtpaq6JgJAZwvnVq3ftVeHafWkcpmuR1e

0
Offline Offline
Newbie
*
Karma: 0
Posts: 41
Arduino rocks
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

John,

Thank you for let me know. I am learning. Should we use different chip for it? What about 74HC164 shift register? Can we use other chips which are easier? I was google and try MAX 6954. I am not sure about it?  I was hope someone can give me a simple way to use 12 of 16 segments LEDs. I am open for any suggestions.

Reid
Logged

Massachusetts, USA
Offline Offline
Tesla Member
***
Karma: 201
Posts: 8684
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

I'm not very experienced with LED matrix design.  The "playground" area of the Arduino site has lots of examples of how to control an array of LEDs.
Logged

Send Bitcoin tips to: 1L3CTDoTgrXNA5WyF77uWqt4gUdye9mezN
Send Litecoin tips to : LVtpaq6JgJAZwvnVq3ftVeHafWkcpmuR1e

Pages: [1]   Go Up
Jump to: