Linked Questions

3 votes
1 answer
7k views

How can Rpi SPI python read the MFRC522 RFID / NFC module?

Trying to read my RFID MFRC522 using a Mifare blue tag and it is not working. Wondering if i could get any help on this as when i put the tag to read it doesn't show up as quick? using: https://...
627117717.pr's user avatar
3 votes
1 answer
3k views

Reducing sound noise when recording with Pi

I am sure everyone trying to record sound with a Raspberry Pi has experienced a lot of issues with noise pollution. Although there is any number threads on various forum adressing this I have yet to ...
Carl-Fredrik von Essen's user avatar
0 votes
2 answers
2k views

How do I use three RC522 RFID readers together?

Ok, So I have one RC522 reader working with no issues. I want to have 3. I don't care which receiver picks up the RFID tag, I just want to know whenever a tag was picked up at all by any of them. ...
Matthew's user avatar
  • 29
1 vote
2 answers
1k views

Power MOSFET Driving Big Motor Problem

I am using the power MOSFET IRF504N. I am not sure if my Rpi's GPIO 3V3 signal can directly input to the gate of the MOSFET which requires 4V minimum. I guess that I don't need a gate driver to shift ...
tlfong01's user avatar
  • 4,665
1 vote
1 answer
888 views

Way to get signal strength from an RFID reader?

I am attempting to make a grid of RFID readers that can triangulate the position of a tag within their read range. I am currently using MFRC522 readers connected to a Raspberry Pi 4 Model B (4gb) and ...
totallyNotLizards's user avatar
2 votes
0 answers
530 views

My rfid-rc522 reader stops reading after some time, how can I debug it?

I'm using the reader below to read mifare cards (13.56mhz), I have an electron/node.js application for this. For some reason after an uncertain amount of time(shortest time I noticed was about 30 ...
crimson589's user avatar
0 votes
1 answer
297 views

RFID and LED Script disables RFID reader until reboot

I have two simple scripts, which work individually. One simply lights an LED, the other reads RFID. Now I want to put them together, but seem to fail. Once this runs, I can't read RFID anymore until ...
lisa-thehexbit's user avatar
1 vote
1 answer
194 views

Can I use the Solenoid lock without an external power supply?

I have a question about the Solenoid lock: can I use it with a 12v relay module without an external power supply? I'm using Raspberry pi 3 model B.
Sh2071's user avatar
  • 11
1 vote
0 answers
174 views

MCP23S17 and multiple RFID-RC522 Modules

Good day all, I am trying to connect a range of RC522 RFID modules to an IO expander MCP23S17 run by a RPI. I am having trouble finding information regarding editing the MFRC522.py modules to allow a ...
J01010's user avatar
  • 29
0 votes
0 answers
51 views

Rpi (Magnetic Door Lock, Relay, Dual SMPS) freezes after not using for 1-2 days. Is memory leaking?

raspberry pi hangs after not using for 1-2 days, then we have to forcibly reboot or restart the device. I have connected hardware of magnetic door lock, relay, RFID and Dual smps to the raspberry pi. ...
Kumar's user avatar
  • 31