Dual Frequency RFID Reader/Writer Wireless Module 5cm ISO14443A EM4100
===

![rfid back](img/s-l1600.jpg)

Cost: $10


| Features | |
|---|---|
| Power |  DC 5-15V |
| Operating Current |  max < 100mA |
| Operating Frequency |  13.56MHz+/-5KHz; 125KHz |
| | Support common ISO14443A protocol |
| | Support EM4100 and its compatible card |
| Card Reading Distance | IC>5cm; ID>5cm |
| | 1 channel Wiegand data output port, support WG26, WG34 multiple format to choose |
| | Card sensor speed is lower than 100ms |
| | 1 channel LED control input |
| | 1 channel BUZ control input |
| Size | `74*115*16mm` |
| Operating Temperature |  -20~60 Celsius |
| Operating Humidity |  10%-95% |

| Pin | Color | Name | Description |
|---|---|---|---|
| 1 | Red | VCC | Power Input Port |
| 2 | Brown | FOR | Wiegand Format Selection |
| 3 | Blue | none | Undefined |
| 4 | Yellow | BUZ | Buzzer Control |
| 5 | Orange | LED | LED Control |
| 6 | Green | D1 | Wiegand Output |
| 7 | White | D0 | Wiegand Output |
| 8 | Black | GND | Power Ground |


| ISO14443 TYPE A |
|---|
| `NXP_Mifare 1K` |
| `NXP_Mifare 4K` |
| `NXP_Mifare mini` |
| `Ultralight(C) ` |
| `Mifare PlusX(S)` |
| `Desfire D21 D41 D81` |
| `NTAG203(F)` |

| 125KHZ |
|---|
| EM4100 |
| EM4200 |
| JT120 |

Data Output Format
---

When it sensors the card, the serial number will be output via Data 0, Data 1 two data wire.

Data 0 and Data 1 are high level when there is no data output.

Logic Definition:

* Data Bit 0: it will generate 200us low level on Data 0 wire
* Data Bit 1: it will generate 200us low level on Data 1 wire

Every data length is 2200us

Every Mifare card has a serial number with 4 bytes, users should output the last three bytes.

Add the first 12-bit even check bit in the front and add the last 12-bit odd check bit in the back, 26-bit data in total.

For example：

* Card number is `6B 3D 12 D6`
* Output data is `3D 12 D6`

Wiegand26 Encode
---

| 0 | 00111101 | 00010010 | 11010110 | 1 |
|---|----------|----------|----------|---|
| Even Check | 3D | 12 | D6 | Odd Check |



Reference
---

* [Ebay Listing](https://www.ebay.com/itm/Dual-Frequency-RFID-Reader-Writer-Wireless-Module-5cm-ISO14443A-EM4100-/122723612753)