Hi Looking for some help. I been testing the RFID reader hooked up to a raspberry pi but not getting and scan reads. Below is a summary of what i have tried so far
Setup Summary
Device: SparkFun Simultaneous RFID Reader - M7E (WRL-24738)
Connection Method: USB-C to Raspberry Pi 4 and macOS
Switch Position: Tested in both “SER” (Serial) and “USB” modes
Operating Systems: Raspberry Pi OS (Linux) and macOS
Serial Devices Detected:
/dev/ttyUSB0
on Pi/dev/tty.usbserial-10
on Mac
What’s Been Tried
1. Power & Connectivity
- Reader powered via USB-C (red power LED confirmed on)
- USB cable verified to be data + power capable
- Switch toggled and tested in both USB and Serial modes
- Serial device successfully detected on both Raspberry Pi and Mac
- Baud rate set to 115200 (as specified in docs)
2. Terminal + Python Testing
Terminal Test:
bash
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screen /dev/ttyUSB0 115200
- Screen opens and closes cleanly
- No feedback or response when tag scanned (even <5 cm)
Python Script:
python
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import serial
import time
SERIAL_PORT = '/dev/ttyUSB0'
BAUD_RATE = 115200
try:
with serial.Serial(SERIAL_PORT, BAUD_RATE, timeout=1) as ser:
print(f"Connected to {SERIAL_PORT} at {BAUD_RATE} baud.")
inventory_command = bytearray([0x04, 0x14, 0x01, 0x00, 0x15]) # Inventory command
ser.write(inventory_command)
print("Sent inventory command. Waiting for response...")
time.sleep(1)
response = ser.read(64)
print("Response:", response)
except serial.SerialException as e:
print("Serial error:", e)
- Python successfully connects to device
- Command sent but no response
- No tag data, no blinking read LED
Confirmed
- Device powers on
- USB cable supports data and power
- Serial port recognized on both Mac and Pi
- Switch positions tested (USB + SER)
- Tags placed within 1–5 cm of onboard antenna
- No tag reads occurred
- Python environment with
pyserial
installed and working