[SOLVED] decade counter 4017 problem

[vishu489]

hi Friends,

i'm trying to build up led matrix display of 8x40 . my problem is that even i'm not supplying any clock to 4017 its Q0 o/p remains high and because of that i'm not able to put my all rows initially off. and when i apply clk to 4017 it get o/p get shifted to Q1 because of that the data corresponding to row1 get displayed on row2. can anyone plz give me any idea how can i make Q0 initially low? i already try with pull down resistor but its not working. can anyone suggest me different ic which works simillar to 4017 and with help of it ,it is possible to make all rows initially low. bythway common cathode are my row segments and common anodes are column. plz help me8-O

 

[kripacharya]

to get zero on all ouput's you have to raise RESET pin High. Make it Low before your first clock pulse.
trying to use a pull down resistor will obviously not work.

You can post your circuit if you want any further help.

 

[vishu489]

even if i'm making reset pin of counter permanently high then also also Q0 is high. i'm checking it on proteus

 

[Yoshidk]

Well 4017 dosnt have a state where all are low.. But just dont connect anything to Q0, and connect your arrays to Q1 to Q9, then when Q0 is active, all your LEDs would be low..

 

[kripacharya]

Well 4017 dosnt have a state where all are low.. But just dont connect anything to Q0, and connect your arrays to Q1 to Q9, then when Q0 is active, all your LEDs would be low..

oh yeah.. its a johnson shifter. good catch. isn't 4017 just 8 bits tho' ? otherwise your's would be the obvious simple solution. He' have to use 4022 i think.

Edit: Nope. 4017 is 10 bit and 4022 is 8 bit. Just use Q1..Q8 for your circuit.

 

[vishu489]

Thank you my friends i solved that problem i connect i/p of uln2803 a to Q1 and Q9 and during first clock it will not do anything and it is finally worked now.
here is my loop

for(Speed = 0U; Speed < 10U; Speed++)
{

for(Temp_Var= 0U; Temp_Var < (MATRIX_ROW + 1U); Temp_Var++)
{
if(Temp_Var != 0U)
{
Feed_Data (Display_Buffer[Temp_Var - 1U]);
Toggle_Counter_Clk();
}
// _delay_ms(1U);

}
Reset_Counter();
}