help : ADC 0804

[Ctrl_Alt_Del]

why my adc 0804 only shows 4 LEDs turn on (B0,B1,B2,B3) 11110000,
and there is no change when i set the input (Vin) between 0v-5v ?

i've try with R and C for clock, and with 555 multivibrator.

 

[Ctrl_Alt_Del]

here is with 555 timer..

 

[kt]

I'm not sure but I think that you must give some pulse to RD pin
to start the convertion(not to tie it to the ground).Read the PDF file of your ADC for details about the RD-WR operation.

 

[williB]

your Vref is supposed to be Vref/2..

https://www.electro-tech-online.com/custompdfs/2005/05/ADC0801.pdf
if you set up a voltage divider ,between 5V and ground , two 10K resistors should do, with Vref/2 tied between them..
it should work properly..
also the pic below , is a scheme to self clock the 0804..