Outputs struggle to maintain a high voltage.

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M.Hansson
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Joined: 17 Jul 2018, 09:43
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Outputs struggle to maintain a high voltage.

Post by M.Hansson »

What is the recommended current [A] to supply the RevPi Core 3 with?
When I set an output to high it jumps between 2-14V inconsistently. I am using RevPiModIO and I am not sure if it has anything to do with my code or an insufficient powersupply. The inputs reads True and False correctly when they receive 0 and 24V respectively.
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dirk
KUNBUS
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Joined: 15 Dec 2016, 13:19
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Re: Outputs struggle to maintain a high voltage.

Post by dirk »

You mean that you use a DIO module, right? ;) In the schematics of the DIO which you may find in the downloads section there is the MAX31913 that converts the values. Here is the datasheet for this device. In this datasheet there are the following values: Low values are save detected at < 7 Volts. High levels are save detected at > 10.2 Volts.
M.Hansson
Posts: 8
Joined: 17 Jul 2018, 09:43
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Re: Outputs struggle to maintain a high voltage.

Post by M.Hansson »

This is true. I do use the DIO module. However if I set Out1 to HIGH and wire that into Input 1. with the following typed into the Shell.

python3
import revpimodio2

rpi = revpimodio2.RevPiModIO(autorefresh = True)

rpi.io.O_1.value = True
(this is wired from O1 -> I1)
rpi.io.I_1.value
(this outputs False)

If i measure O_1 with a multimeter it jumps between 0.1V - 24V very irregularly. Which is why I feel like maybe I can not supply enough power.
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dirk
KUNBUS
Posts: 1924
Joined: 15 Dec 2016, 13:19
Answers: 4

Re: Outputs struggle to maintain a high voltage.

Post by dirk »

Is there a PWM active? Are the outputs in High-Side mode or in Push Pull?
What connectors do you use?
Is there another process accessing the outputs?
Can you use an Oscilloscope instead of a digital multimeter?

I have successfully tested your setup and code with a RevPi Core 3 a DIO and one of those 2.54mm Dupont Jumper Wire Connectors from output 1 to input 1.

Please check or re-init your configuration. In this tutorial you may find the settings
  • OutputPushPull
  • OutputPWMActive
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