Hey (I apologise if this is in the wrong place),

On my current circuit (its a electronic poker chip device) currently the inputs are PTM which send out pulses, however, I would instead like to give the option for the user to input the amount they want with a key pad - its the 3 x 4 one from RapidOnline. However, I have no idea on how to code the E28 chip to work with it - how would you go about coding it??

Best regards

Josh

P.S. I am using the latest circuit wizard.

 

What is an "E28" chip?

 

What is an "E28" chip?

Its a pickaxe chip, its (I believe) made by Genie - who make circuit wizard.

If you want I can take a screen shot of my current circuit - although I have removed the PTMs

 

photo's will help?

 

need a few minutes to read this over, but it might give ideas.

http://www.edn.com/article/489344-Key_reading_circuit_saves_I_O_pins.php

 

Well I can't access Circuit Wizard till tomorrow, however, I can explain the chips I have in it to you.

At the start I had 4 PTM's (with resistors to hold low) going into a C20 (like an E28 but less memory); from there the one output goes to a 4510 which goes to a 4511 - which goes to the 7 segment displays; thats the basic version of it.

 

I have attached a picture of the wiring of the keypad I wired up, however, each row, when pressed i.e. for the first row with the LED. When either 1, 2 or 3 is pressed it lights up the LED even though its only meant to be 1....

I have also attached the counting part of my circuit, i.e. the chips for the 7 segment display.

Regards,

Josh

 

I can't understand your circuit, but keypads are usually read by a scanning process. If you have a processor that can do that, it saves using any other components. Procedure is, ground one column and see if any row goes low; if not, ground the next column and see if any row goes low; if not, ground the last column and see if any row goes low; if not, nothing's pressed.