Wireless control of solenoid valve


I have been making my first arduino project for a while now and have finally put it together. its an arduino uno with a relay sheild (One-stop Online Shop For Smart Home, HMI Display, Airspy, Diy Kits l ITEAD STUDIO) and an nrf24l01. there are 2 of these one is the sender and one is the receiver.
Basically it switches a solenoid on and off wirelessly.
It all works fine until i connect the solenoid, when the solenoid is connected to the relay it will only turn on and off once. After this the receiver needs to be reset and then it will do it once again.
i have tried separating the power supplies for the board and valve and it still does the same thing.
when i disconnect the solenoid the relay can be switched as many times as you like.
Any ideas why?

Thanks is advance,



Have you got a reverse biased diode across the solenoid.
It will suppress the back EMF of the solenoid when it is turned off.
Turning off a solenoid/coil will cause a current/voltage spike that will interfere with the arduino?
A 1N4007 will do the trick.
Tom.... :slight_smile:

I did think about that but i would have thought if i put them on seperate power supplies it couldnt give the board a surge when it turned off could it?


It will help improve the life of the relay contacts too.

Tom... :slight_smile:

Even if it doesn't interfere with the arduino, it will interfere with the wireless device at the solenoid. Or is there 2 arduinos ?

There is 2 arduinos. I'll get what tom suggested and try that.

Thanks for the advice