Arduino Temp Controlled Heater - Connecting to Main AC 220v

Using Arduino Programming Questions
1

Hi All,

I have built, coded and tested an Arduino with DHT11 Temp & humidity Sensor and Relay
This will switch on the relay when Temp goes below 17 and turn off when Temp is above 22

I am happy with my build and ready to implement.

I only have one question - Powering the Arduino with Mains AC (In "Series" with the Heater if you will)

I don't want to have two power Supply's and I also don't want to Die. Taking a cautious approach

Some advice from more seasoned users would be much appreciated.

Can I use a USB 2 Pin Adapter (Iphone Charger) to Power the Arduino in this setup?

2

With “series” Do you mean connecting like this?

                 ____ RELAY ——HEATER 
                |
220VAC Main ——|—— iPhone USB <— usb cable —> Arduino power Jack

and arduino digital pin driving the relay?

Playing with 110 or 220v ac main is always dangerous. If you are unsure of what you do, then don’t...

3

Are you using an opto isolated relay module?

4

There are many modern power adapters that allow you to take 5VDC of the mains and if you're using a solid state relay of marginal quality, you're already isolated. If you're using an electro-mechanical relay, all bets are off.