Analog input as trigger for relay(s)


I have a bit of a problem configuring a VM204 relay card. Before setting off I was not aware that this card required a deeper understanding in programming. I’m not a programmer myself so any and all help is very much appreciated in this case.

To my issue. I have an analog input signal that vary between 5,5 to 7,5 volts. I’d like to use the signal as a trigger, so that when the voltage rise above 5,5V relay 1 and 2 triggers an impulse set to 900 seconds. To make my issue a bit more complicated (at least for me) this is also something I’d like to have encoded in the firmware to make it a set-forget type of thing.

Background to my request:

The reason behind all this is an overflow swimming pool with an automatic system to deal with internal cirkulation and buffer tank operation. In the system I need to pause the external heat pump as well as the chemical dosing system every time the buffer tank is activated. The trigger for this is the analog pump speed control that rise from 5,5 to 6,5 volts when buffer tank is activated. The pool controller can not handle this type of logic and all my other trigger outputs are 230V / 2-10A.

Again, I have no experience with programming or compiling.

Can anyone please help me with this?

Hi @SwimLAB,

What you ask is possible with the VM204, but it requires changing the firmware of the board.
We have created the VM204 already pre-programmed so it’s ready to be used on a number of applications. Your application however, is not possible with this standard firmware.

To support a wider range of applications, we have made the firmware open source, you can find it here: However, to change this, it requires a good understanding of programming. If you have no experience with programming, you will need some assistance from other programmers on this forum.

There is already an option in the current firmware to send an e-mail if the analog value rises above a threshold. You simply need to add code to control the relay when that happens.

Kind regards,