Author Topic: GPIO Output  (Read 405 times)

Offline tbone321

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Re: GPIO Output
« Reply #15 on: November 29, 2018, 10:41:19 AM »
You might want to post a few pictures such as your PI GPIO output configuration screen and a photo of how you set up the relay board.  The PI can be standalone and doesn't require anything more than FPP running on it to test but the output GPIO channels do need to be properly defined and the board needs to be wired correctly. 

Offline Martin.S

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Re: GPIO Output
« Reply #16 on: November 29, 2018, 02:52:01 PM »
This is a 12V board, you need a 12V Power supply


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Offline Martin.S

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Re: GPIO Output
« Reply #17 on: November 29, 2018, 03:05:09 PM »
8 Channel need 5V, 16 Channel need 12V. You can drive   8 channel from the pi3 if your power Supply have 2.5 ampere, netter 3 A


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Offline Adbrig4

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Re: GPIO Output
« Reply #18 on: November 29, 2018, 09:42:49 PM »
Hello, It is working correctly if I power the 8 channel relay board from the Pi 3. If I were to power it externally would the Pi3 and the relay board have to share a ground from the external power supply? Also when I tried it with the external power adaptor I removed the jumper from the VCC--JD it that correct?

Offline tbone321

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Re: GPIO Output
« Reply #19 on: November 29, 2018, 10:34:28 PM »
No they do not share anything.  The relay board has 2 separate power systems, one for the triggers and the other for the relay coils.  The Triggers use the VCC connection for +5V from the PI and gets the grounds on the trigger pins which is why you select the inverse option when defining the GPIO channels.  The relay coils use the JD-VCC and Ground connections.  Your board should have 2 VCC pins and 2 Ground pins, one set on each end of the trigger pins and the other in a small three pin connection with the JD-VCC pin and the jumper connecting the VCC and the JD-VCC pins together. 


When you are powering the board from the PI, the VCC pin near the trigger pins is connected to a PI 5V GPIO pin and the ground pin near the trigger pins is connected to one of the PI's GPIO ground pins and the jumper is left in place between the VCC and JD-VCC pins.  The jumper simply passes voltage from the VCC pin to the JD-VCC pin to power the relay coils from the VCC connection and the ground connection supplies the ground for the coils.  When you decide to power the relays from a separate power supply, you remove the ground connection from the PI to the board and remove the VCC JD-VCC jumper from the 3 pin connector.  Then you connect the power supplies +5V lead to the JD-VCC pin on the 3 pin connector and the power supplies ground to one of the 2 ground pins on the board.  You can use either one as they are both connected together.  I use the one on the 3 pin connector because it just looks cleaner.  Do not leave the ground connected to the PI because it is not needed and eliminates the electrical isolation that the board can provide for the PI's GPIO. 

 

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