DIY Motorized Standing Desk Part V: Test with 3 actuators controlled from Raspberry Pi

Edit: here is the final operational desk, utilizing the 3 actuators

I have the control board for my DIY motorized standing desk wired up, and ran a test of the board controlling 3 linear actuators at the same time.  I knew the wiring and software worked for 1 actuator, but this was the first time that I connected more than one actuator up.  The desk will be lifted by 3 actuators so I needed to be sure this worked.

Here it is, worked on the first try and nothing caught on fire!

One thing of note – I had initially planned to control each actuator independently from the Raspberry Pi, with each relay signaled from a different GPIO pin.

However, in the midst of wiring the control board up I realized that it was possible that a software bug, crash, or other unforeseen scenario on the Pi could theoretically result in actuators moving in different directions, and that would be a Very Bad Thing (images of broken desks, shattered monitors, and crushed babies come to mind).

So they are all wired now on 2 GPIO pins (one for the “A” relays, and one for the “B” relays).

So now the leg apparatus’ are built, and the control board is working.  Next step: put it all together!

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3 thoughts on “DIY Motorized Standing Desk Part V: Test with 3 actuators controlled from Raspberry Pi

    1. Thanks! The actuators are running from a 12V/12A DC power adapter. This is the one I’m using, though I feel like I got it for quite a bit less than it’s currently listed for – http://www.firgelliauto.com.au/products/dc-power-adaptor

      The tricky part (for me, very much an amateur) was splitting the power and ground 6x so that it could be fed into the relays (each actuator requires 2 relays). Eventually I discovered that there are multi-port wire connectors to make this simple – http://bit.ly/1P4wIqL

      The Raspberry pi is running via a typical 5v power source; I didn’t attempt to power it from the higher powered actuator source for fear of frying it. 🙂

      Like

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