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Repurposing a solenoid array to communicate with arduino

mforbes

Feb 16, 2023
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Feb 16, 2023
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I harvested a PCB from a tecan cavro multichannel pump (pdf manual attached). I want to control just the solenoid 3 way valves via arduino. One PCB seems to control all 8 solenoids which are 24VDC (current I'm not so sure). From what I can see two darlington transistors control 4 valves each. My question is, how would I go about working out which of the pins to provide the 24VDC to and which pins I can switch the solenoids with?

I've attached an image of the PCB
1676555051892.png
 

Attachments

  • manual. Cavro XMP Pump. low res. 737847-A MANUAL XMP6000.pdf
    1.9 MB · Views: 2

kellys_eye

Jun 25, 2010
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Jun 25, 2010
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It's not RS232 controlled. It's a 'simple' serial data stream (clock/data and maybe reset) fed straight to the shift registers.

Get the shift register datasheet and you will be able to trace the relevant signal (pins) lines back to the box connector.

The shift registers will (probably) work from 5V so there will be a pin for that supply as well as whatever is used for the solenoids. The solenoid supply voltage could be 'anything' as the supply line will be switched via the relevant drive transistors that themselves will be controlled from the output of the shift registers.

Need better (closer) pictures of the boards
 

mforbes

Feb 16, 2023
2
Joined
Feb 16, 2023
Messages
2
It's not RS232 controlled. It's a 'simple' serial data stream (clock/data and maybe reset) fed straight to the shift registers.

Get the shift register datasheet and you will be able to trace the relevant signal (pins) lines back to the box connector.

The shift registers will (probably) work from 5V so there will be a pin for that supply as well as whatever is used for the solenoids. The solenoid supply voltage could be 'anything' as the supply line will be switched via the relevant drive transistors that themselves will be controlled from the output of the shift registers.

Need better (closer) pictures of the boards
Hi!,
Thank you for the reply, I've been wondering how to do this for a while now. So, I know the solenoids are 24VDC so I guess the input to the board should be that. The shift registers are these:
I need to do some reading around how these registers can work with my arduino, but if I can provide the 24V first then I can work out the pins one by one. I'll try and get better pictures and remove the connector to see the pins.
Thanks
 
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