- This topic has 1 reply, 2 voices, and was last updated 13 years, 1 month ago by
.
-
Posts
-
hello,,, i had start to make a 8051 project of scrolling led display that uses IC ULN2803 and IC 74LS164 but i dont know anything of these ics ,,,, i had searched on google many times but i dont found anything important for me ,,, i had downloaded datasheet also but its not enough so please tell me some sites that contains whole information about these and almost all ics ,,,,, tell me something that contains start to end data of these …… please help me i will be very grateful to u…..thanksdharmik
I’ve gone through the datasheet and one thing I’ve noticed is that ULN2803 has 8 input and 8 output pins, and 74164 is a 8 bit serial to parallel convertor. So I thing you are trying to make a 8*8 led matrix display.
Connect 8 output pins of the controller to 8 inputs of ULN2803. Connect your serial data_out pin of the controller to any of the two inputs of 74164, while keeping the other input pin high. Connect the 8 raws to the 8 output of 74164, and 8 columns to 8 outputs of ULN2803. And you scan the matrix column wise.
Cosider the first column,
Send 8 bits of the data to the input of 74164, Turn on the output of ULN2803 corresponding to the first column by making the respective pin of the controller high. Before going for the next column, turn of the current column. Do the same for all the columns.
You have so many sites
- You must be logged in to reply to this topic.