Hello to everybody..!
I am new to this forum,, Can anybody please help ,,
I am trying display animations on 2 led dot matrices.. such that their rows are connected together (5x14) ,,
now the problem is that i am unable to drive my dot matrix using uln2003a . I am using pic18f452 which is programmed with the animation. our teacher told us that to drive the dot matrix with uln, we would have to use it with pull up resistors. Without attaching the pull up resistors, and directly connecting the uln with the dot matrix , it powers up but does not switch due to which my leds are constantly on and there is no animation . when i connect the dot matrix with the pull up configuration, my leds dont even get powered up. i have written the code in a common anode configuration .( rows require logic 1 and columns require 0 logic ) our teacher also told that uln inverts the logic, so i have also tried to use an inverter(74hc04) before the uln to invert the code, but still my led dot matrix does not work . Please help. i have to submit the project by next tuesday.. .. what should i do..
I am new to this forum,, Can anybody please help ,,
I am trying display animations on 2 led dot matrices.. such that their rows are connected together (5x14) ,,
now the problem is that i am unable to drive my dot matrix using uln2003a . I am using pic18f452 which is programmed with the animation. our teacher told us that to drive the dot matrix with uln, we would have to use it with pull up resistors. Without attaching the pull up resistors, and directly connecting the uln with the dot matrix , it powers up but does not switch due to which my leds are constantly on and there is no animation . when i connect the dot matrix with the pull up configuration, my leds dont even get powered up. i have written the code in a common anode configuration .( rows require logic 1 and columns require 0 logic ) our teacher also told that uln inverts the logic, so i have also tried to use an inverter(74hc04) before the uln to invert the code, but still my led dot matrix does not work . Please help. i have to submit the project by next tuesday.. .. what should i do..