Hi, I am new to this forum having bought a K8055 board.
I understand that the 8 digital outputs are open collector.
I do not want to use the outputs to drive a relay, but as digital inputs to a Picaxe microprocessor.
The Picaxe board is powered by a 5V supply.
From what I have figured out so far, I must connect the Picaxe 0volt line to GND on the K8055, and the 5V line to ‘CLAMP’.
I am a bit uncertain of what resistor configuration is needed between the K8055 output and the Picaxe input.
What value resistor is used and should it be ‘pull-up’ or ‘pull down’?
A sketch of the circuit would be ideal.
Many thanks,
George
[quote]What value resistor is used and should it be ‘pull-up’ or ‘pull down’?
A sketch of the circuit would be ideal.[/quote]Here’s a sketch:
Many thanks,
that is exactly the answer I need.
I have another query.
I will use the output of an optoswitch as an input to the K8055.
The circuit for the switch is:
Is there a need to add the pull up resistor Rl?
If so, there is no convenient Vcc positive rail on the K8055.
Where would this connection be made?
There are pull-up resistors on the board. So no need for external resistor.
You’ll find the voltage +5V for Vcc on the jumper pin of SK2 and SK3.
Many thanks!