28140 Parallax Inc, 28140 Datasheet - Page 2

• Manufacturer Part Number: 28140
• Description: READER MODULE RFID
• Manufacturer: Parallax Inc

Specifications of 28140

• Rf Type: Read Only
• Frequency: 125kHz
• Features: Single 5V Power Supply
• Package / Case: Module
• Product: Microcontroller Accessories
• Data Bus Width: 8 bit
• Clock Speed: 125 KHz
• Interface Type: USB
• Operating Supply Voltage: 5.5 V
• Board Size: 46.99 mm x 69.22 mm x 21.84 mm
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant

RFID Compatibility
The Parallax RFID Card Reader works exclusively with the EM Microelectronics EM4100-family of passive
read-only transponder tags. Each transponder tag contains a unique, read-only identifier (one of 2
1,099,511,627,776 possible combinations).
A variety of different tag types and styles exist with the most popular made available from Parallax.
Connections (Serial)
The Parallax RFID Card Reader Serial version easily interfaces to any host microcontroller using only four
connections (VCC, /ENABLE, SOUT, GND).
Use the following example circuit for connecting the Parallax RFID Card Reader:
Copyright © Parallax Inc.
Note: Type: I = Input, O = Output, P = Power, G = Ground
Pin
1
2
3
4
Pin Name
VCC
/ENABLE
SOUT
GND
Type
P
I
O
G
RFID Card Reader Serial & USB (#28140 / 28340)
Function
System power. +5V DC input.
Module enable pin. Active LOW digital input. Bring this pin LOW to
enable the RFID reader and activate the antenna.
Serial output to host. TTL-level interface, 2400 bps, 8 data bits, no parity,
1 stop bit.
System ground. Connect to power supply’s ground (GND) terminal.
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