# RPi HAT: PI-485

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SKU: SC220102
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{% hint style="info" %}
EAN:6976158320007
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<figure><img src="https://389921961-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FjPowryxiQvRDiYHC9qWy%2Fuploads%2FcUSyrGgUbXOBWa1SVatz%2FDSC_3441.jpeg?alt=media&#x26;token=44d4aca3-e0d4-4ba1-a723-90759b3edf09" alt=""><figcaption></figcaption></figure>

The RS485 HAT from WisdPi is a fully galvanic isolated Serial communication HAT designed for use with the Raspberry Pi.

RS485 can be used across large distances, so isolation of the RS485 bus ensures that your Raspberry Pi is fully protected!

RS485 is in use in many applications like industrial and home automation (for example MODBUS), lighting control (DMX), video surveillance (for example Pelco D) and many more!

## Features

* RS485 mode (half-duplex)
* Galvanic isolation between Raspberry Pi and connected RS485 bus&#x20;
* Enhanced ESD protection&#x20;
* Adjustable automatic transceiver switching for RS485 mode&#x20;
* Adjustable control of transceiver/receiver via GPIO pin&#x20;
* Adjustable Pull-Up, Pull-Down und terminating resistors&#x20;
* Indicator LEDs for RX and TX&#x20;
* Many options are adjustable via DIP switches
* Send/Receive Control
* Male DB9 Socket
* Screw Terminal Block 5mm
* CA-IS3082W IC
* TX/RX/GND Solder Points

## Electrical Characteristics

* Max Datarate: 10Mbps
* Number of nodes: 50
* ESD: 4kV(JEP155)/2kV(JEP157)
* Isolation Rating: 1000 Vrms
* Working Voltage: 1414 Vpk
* Operating Temp:  -40℃ \~ 125℃
* Power Consumption： 14.4mA(3.3V) / 14.4mA(5V)

## Block Scheme

<figure><img src="https://389921961-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FjPowryxiQvRDiYHC9qWy%2Fuploads%2FuF25p1H1DR1MlAqlVnLn%2FRS485%20HAT%20for%20RPi%20%E7%B3%BB%E7%BB%9F%E6%A1%86%E5%9B%BE.png?alt=media&#x26;token=b227e987-f732-4c49-b1ad-ef42bf8b980e" alt=""><figcaption></figcaption></figure>

## Control Elements

<figure><img src="https://389921961-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FjPowryxiQvRDiYHC9qWy%2Fuploads%2Fmi8cdNFJc7KAn4U3doiA%2F%E8%AF%B4%E6%98%8E%E9%85%8D%E5%9B%BE.png?alt=media&#x26;token=e1860ffd-6f81-405c-97f2-aef34f12825f" alt=""><figcaption></figcaption></figure>

| NO. | Description           | Spec                     |
| --- | --------------------- | ------------------------ |
| 1   | RPi UART TTL          | 2.54mm Male Header Pins  |
| 2   | Send/Receive Control  | DIP Switch S1            |
| 3   | RS485-A/RS485-B       | Male DB9 Socket          |
| 4   | RS485-A/RS485-B       | Screw Terminal Block 5mm |
| 5   | Termination resistors | 2.54mm Male Header Pins  |

### RPi UART TTL (2.54mm Male Header Pins)

| NO. | Description | Raspberry Pi GPIO Pins |
| --- | ----------- | ---------------------- |
| 1   | GND         | GND                    |
| 2   | TXD         | GPIO14                 |
| 3   | RXD         | GPIO15                 |

### Send/Receive Control (DIP Switch S1)

<table><thead><tr><th>Channel</th><th>Description</th><th data-hidden></th></tr></thead><tbody><tr><td>1</td><td>Receiver always on</td><td></td></tr><tr><td>2</td><td>Transmitter connected to Receiver</td><td></td></tr><tr><td>3</td><td>Automatic DE/RE control</td><td></td></tr><tr><td>4</td><td>DE/RE control via GPIO18</td><td></td></tr></tbody></table>

### RS485-A/RS485-B (Male DB9 Socket)

<figure><img src="https://389921961-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FjPowryxiQvRDiYHC9qWy%2Fuploads%2FwKx1qGRJi1gRGVhnhbAb%2FPI485%20%E6%8E%A5%E5%8F%A3.png?alt=media&#x26;token=5bb4756d-09ef-46fd-a8a6-dfffb9c4b279" alt=""><figcaption></figcaption></figure>

### RS485-A/RS485-B (Screw Terminal Block 5mm)

<table><thead><tr><th>NO.</th><th>Description</th><th data-hidden></th></tr></thead><tbody><tr><td>1</td><td>RS485-A</td><td></td></tr><tr><td>2</td><td>RS485-B</td><td></td></tr><tr><td>3</td><td>GND</td><td></td></tr></tbody></table>

## How To Use

### Step 1:

Connect the Hat board to the GPIO pins of the Raspberry Pi.

![](https://389921961-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FjPowryxiQvRDiYHC9qWy%2Fuploads%2FcM7Ayg9cOY65I8lqpcoD%2Fimage.png?alt=media\&token=2fbf218b-3d7f-4d07-950a-1ed5cef330de)

### Step 2:

Use RS232 just like a common Raspberry Pi&#x20;

{% content-ref url="../blogs/how-to-use-raspberry-pi-uart" %}
[how-to-use-raspberry-pi-uart](https://wiki.wisdpi.com/blogs/how-to-use-raspberry-pi-uart)
{% endcontent-ref %}

## Outline Dimensions

* 65x62.5x25.7mm

## Weight

## PACKAGE CONTENT

* Pi-485 HAT x 1
* Screwdriver x 1
* Screws pack x 1