I’d like to connect some of the K8055 digital outputs to the inputs of another external controller.
The external controller provides a 5V power supply.
Its digital control inputs require 5V (I think the load is around 8K).
If I connect the 5V power to K8055, I can’t see any simple way to have the K8055 outputs drive the 5V inputs, other than using coupling devices. Any ideas/suggestions?
Thank you
-Yoma
Have you tried the pull-up resistors (e.g. 470 ohm) to the digital outputs of the K8055? That way you get nearly 5V output swing.
Connect the resistors to the external +5V.
[quote=“VEL255”]Have you tried the pull-up resistors (e.g. 470 ohm) to the digital outputs of the K8055? That way you get nearly 5V output swing.
Connect the resistors to the external +5V.[/quote]
Yes that does the job thank you.
I’d like to ‘re’ invert the output.
Before my host application is run, the outputs are high which results in the controlled heater, fan being on.
Should I add an inverting op-amp? Or is there a simpler way
Thanks
-Yoma
You could add a PNP transistor
hello i’m an intruder.i have a question.how i connect the pins of the PNP transistor for it works?
and it go after or before the resistor?
i supose the total circuit to control another inputs well is to connect a resistor for each out of k8055 then the power suply(1 for all outs) and then the PNP and then connect to the inputs of the onther device
i want to test the ports of one pic and train with it.
good bye
and thanks for this great forum
Connect the base of the PNP transistor via a 10k resistor to the digital output of the K8055.
Connect emitter of the transistor to the positive (external) supply voltage.
Connect the collector of the transistor via a 2k2 resistor to the GND of the K8055.
Connect the external power supply GND to the GND of the K8055.
You do not need any pull-up resistors in this case.