My arduino nano 33 iot would have the wifi disconnected the moment i plug in an external source (7.4V lithium battery). I have attached an image of my connection as shown. I need to power 20 of these circuit boards and i will have 2 pins connected to 1 circuit board.
From my arduino nano 33 iot, i will have 18 pins connecting to a circuit board. From pin 1 to 18, the circuit board is shown with the use of a transistor, that would mean i will only get to connect 9 boards. For the remaining 11, they are connected via PCF8574 extension board and instead of using transistor, I'm using a mosfet. The positive inputs to the relay coil is all connected to 1 rail for both the transistor and mosfet and likewise for the ground.
The moment I connect my 7.4V to it, my board just disconnects from arduino cloud and shows me this error, attached below as well. When the power supply is not connected, it shows that i'm connected to the arduino cloud iot.
I'm not really a hardware person. Are your relays relay modules or just relays? For the latter,
You're missing flyback diodes over the transistors.
What is the coil current?
Why do you mix BC337 and IRLZ44? I doubt that the BC337 is suitable to drive relays. The base current will be around 0.5mA and with a worse case HFE of 60 you can only drive 30 mA (as said, not really a hardware person so I can see this wrong).
Hello! My relays are individual relays, not modules.
I do have flyback diodes on my transistors.
The Coil current is approximately 71mA.
I used BC337 for the arduino due to the source current and for programming it would be more intuitive. The PCF8574 has higher sink than source hence it is much difficult to use the BC337, hence using the IRLZ44 would allow me to "source" current.
I had no issues when i was testing them during batches of 3 - 4 but now that everything is put together, the arduino NINA isn't working as it is intended
