Getting Moteino M0 to work with MRFC522 RFID chip

[ydylwj23]

Hi everyone,

I'm trying to use the popular MRFC522 RFID chip to build wireless security system but can't get two boards to communicate. Does anyone have any experience with this? I haven't got a chance to try regular 328 Moteino but once the order arrives I'll do it right away.

Also, I realize that there's no pin connected to LoRa's RST pin from Moteino. How come this is the case? I thought this is one of the essential pin to work with when using LoRa so Serial flush doesn't interfere with the SPI bus.

Thank you

[Felix]

Also, I realize that there's no pin connected to LoRa's RST pin from Moteino. How come this is the case?

Do you reset the board often?
Do you need to hard reset the radio?
The schematic shows it as non connected.

[ydylwj23]

Not too often, only once during setup, according to RadioHead's example:

Code Select Expand

// Ensure serial flash is not interfering with radio communication on SPI bus
//  pinMode(4, OUTPUT);
//  digitalWrite(4, HIGH);

Most other LoRa embedded microcontrollers have this pin connected. I'm still trying to test more to see if this is absolutely necessary.

[Felix]

//Serial flash ?? 

And Pin 4 is ... what exactly?

Anyway it's not necessary. And if you really want it, you can add it yourself with a short hookup wire from module RST to your desired pin. Why hardwire and use a pin for this purpose? To account for buggy code?

See the linked RadioHead library on this page. It does not require any reset.

[ydylwj23]

LOL sry, pin 4 is connected to RST pin.

Got it. Thank you!