So I have connected an Arduino to a 240 V SSR to switch a pump on and off and I have an LCD (hooked up to the Arduino also) constantly reporting the status of the pump.
I have connected the LCD to the Arduino using shielded twisted pair cabling, It has a .1uF capacitor connected across GND and PWR to filter out any noise on the power lines.
The SSR is connected to the Arduino using a sheilded twisted pair cable in a further attempt to filter out any noise.
Each time the pump comes on or off the LCD scrambles and the only way to fix it is to turn the power off and then back on.
I am aware of the script that re-sets the LCD without re-powering but I feel as though solving the problem at the source will be a better way to deal with this.
If anybody has run into this kind of 'Interference' Issue before and found a solution that they might believe helps I would really appreciate it.
What SSR are you using, and is the input signal optically isolated?
How from from the Arduino is the LCD? If the lcd is remote, you might try and bring it close to the arduino and try to determine if the noise problem is from the arduino to the lcd, or from the ssr to the arduino.
You might try wrapping all the wires to/from the arduino to the SSR (and lcd if its remote) on a torroidal ferrite choke.
If anybody has run into this kind of 'Interference' Issue before and found a solution that they might believe helps I would really appreciate it.
There have been many similar problems posted on this forum. The forum search feature is well hidden (green on green) near the upper right, but it doesn't work very well anyway. Try scrolling through the recent posts.
Hi, thanks for your reply. I am using a solid state relay rated to 40Amps... I am not sure I fully understand the concept of opto-isolation. I am simply using a control pin on the arduino and the ground pin on the arduino.. I have put a capacitor (.1uF) across the pins and a small resistor in series with the control pin and the wire to the SSR to function as a low pass filter.
I will test whether the interference is coming from the SSR or the arduino. The LCD is remote and though it doesn't fix the problem, it does make it less extreme the further away the LCD from everything else.
Hi csimpson, I had, what I believe is the same problem. I have a lithe air pump (from an aquarium) driven by an relay. When I turned off the pump the LCD scrambled too. After many attempts I gave up an I "solved" the problem waiting a few ms with a delay function and restarting the LCD with the lcd.begin function. Until now, I had no problem anymore.
EDIT: I must write everything back to the screen after restarting, but was the only way to deal with the problem.