Hi, i have a project and i need help. basically, what i want to do is to control a water pump using arduino uno r3 thru blynk using the nodemcu for the wifi connectivity.
i tried using a esp32 and a nodemcu as a standalone device for the relay but it cant power the Fotek SSR 60DA relay that i am using. so i connected the relay to a arduino uno.
Is there any way how i can control the relay using arduino and nodemcu in blynk??
I’m a bit confused by what you’re saying here, but there is a far simpler solution.
Fostek Don’t list a 60 amp DA SSR, but they dop list 50A and 75A SSR’s on their website, and the important part (from an MCU point of view) are that the specs for both are the same…
This means that the SSR needs a trigger voltage of at least 3.5v to hold it latched in the ON state, and your problem is that ESP8266 and ESP32 MCUs use a logic level of 3.3v on their GPIOs, so setting the GPIO to HIGH won’t be suifficent to trigger the SSR.
By far the simplest way to fix this is with a very cheap and simple logic level shifter, like this…
On the HV (High voltage) side you connect HV and HND to 5v and GND on your ESP device and HV1 to the trigger pin on your SSR.
On the LV side you connect LV and GND to 3.3v and GND on your ESP device, and LV1 to the GPIO pin that you’re using to control the SSR.
This will result in a 5v output on HV1 when a 3.3v input is applied to LV1
You can achieve the same thing with a simple transistor circuit, or you could even be super messy and use a relay that will trigger from 3.3v to switch 5v that will trigger your SSR.
Either way, an Uno and ESP together is a very poor approach to the problem.
Pete.
hi, That would be a wonderful solution with much more efficient and clean results i guess. The only problem is that my professor requires me to turn on/off the relay with arduino uno and nodemcu in blynk as it is the one stated in our school activity. There’s really no room for reconsideration with him so im scratching my head a bit here on how to do it…
Maybe you should have made that clear up-front.
I tend to focus my time on helping people with real-world solutions, rather than hypothetical ones that are dictated by people who should know better.
Good luck with your assignment.
Pete.
I see you’ve flagged my last post as inappropriate. I’ll let one of the other moderators decide how it should be handled.
Pete.
