m5-docs/docs/en/unit/iso485.md

# Isolated RS485 Unit {docsify-ignore-all}

<el-tag effect="plain">SKU:U094</el-tag>

<div class="product_pic"><img src="assets/img/product_pics/unit/iso485/iso485.webp"></div>

## Description

**Isolated RS485 Unit** is an isolated half duplex transceiver based on the RS485 bus protocol. It can convert TTL level to RS485 level. Since various electrical noises and transient changes of voltage and current may affect communication, Using CA-IS3082W as an interface chip can effectively shield the above noise and provide sufficient protection for expensive control equipment and reduce the risk of damage.

Communication with RS485 devices requiring long-distance signal transmission is possible. The product has a failure protection function whereby in the receiving state, if the input is open or short circuited, the receiver output level is high.

RS485 is a communication protocol standard, which is used to define the electrical characteristics of drivers and receivers used in serial communication systems. It supports Multipoint Systems and is widely used in industrial fields.

When the project equipment needs communication control through RS485 and has high requirements for signal-to-noise ratio and transmission distance, it is a good choice to use ISO485 unit for interface type transfer.

## Product Features

- Built in CA-IS3082W isolation chip
- Indicator light
- Isolated DC-DC
- Signal transmission rate: up to 500 Kbps
- Fail safe receiver (bus open, short circuit)
- Supports up to 256 bus nodes
- Up to 1000 VRMs isolation and withstand voltage
- Development platform: Arduino, UIflow (Blockly, Python)
- 2X LEGO™ compatible holes

## Include

- 1x Isolated RS485 Unit
- 1x VH-3.96 4P
- 1x 120Ω resistance
- 1x Grove Cable(20cm)

## Applications

- Communication between RS485 interface device and microcontroller in industrial equipment

## Specification

<table>
   <tr style="font-weight:bold">
      <td>Resources</td>
      <td>Parameter</td>
   </tr>
   <tr>
      <td>Withstand voltage value</td>
      <td>1000V</td>
   </tr>
   <tr>
      <td>Maximum number of nodes</td>
      <td>256个</td>
   </tr>
   <tr>
      <td>ESD</td>
      <td>±15KV</td>
   </tr>
   <tr>
      <td>Protection function</td>
      <td>Failure protection, over-current protection and thermal shutdown protection</td>
   </tr>
   <tr>
   <td>New Weight</td>
      <td>13g</td>
   </tr>
   <tr>
      <td>Gross Weight</td>
      <td>25g</td>
   </tr>
   <tr>
      <td>Product Size</td>
      <td>56mm*24mm*11mm</td>
   </tr>
   <tr>
      <td>Package Size</td>
      <td>70mm*55mm*13mm</td>
   </tr>
 </table>

## EasyLoader

>EasyLoader is a concise and fast program writer, which has a built-in case program related to the product. It can be burned to the main control by simple steps to perform a series of function verification. Please install the corresponding driver according to the device type. M5Core host [Please click here to view the CP210X driver installation tutorial](en/arduino/arduino_development), M5StickC/V/T/ATOM series can be used without driver)

<div class="easyloader-box">
    <div style="background-color:white;">
        <div><img src="https://m5stack.oss-cn-shenzhen.aliyuncs.com/image/easyloader_intro.webp"></div>
        <div class="easyloader-btn">
            <a href="https://m5stack.oss-cn-shenzhen.aliyuncs.com/EasyLoader/Windows/UNIT/For%20M5Core/EasyLoader_ISO485_UNIT_With_M5Core.exe">Windows</a>
            <a href="https://m5stack.oss-cn-shenzhen.aliyuncs.com/EasyLoader/MacOS/UNIT/EasyLoader_ISO485_Unit_For_M5Core_.dmg">MacOS</a>
        </div>
    </div>
    <div>
        <video id="example_video" controls>
            <source src="https://m5stack.oss-cn-shenzhen.aliyuncs.com/video/Product_example_video/Unit/ISO485.mp4" type="video/mp4">
        </video>
        <div class="easyloader-mask">
        <a>
            <svg id="play-btn" t="1583228776634" class="icon" viewBox="0 0 1024 1024" version="1.1" xmlns="http://www.w3.org/2000/svg" p-id="4152" width="75" height="75"><path d="M512 0C229.216 0 0 229.216 0 512s229.216 512 512 512 512-229.216 512-512S794.784 0 512 0z m0 928C282.24 928 96 741.76 96 512S282.24 96 512 96s416 186.24 416 416-186.24 416-416 416zM384 288l384 224-384 224z" p-id="4153" fill="#007aff"></path></svg></a>
            <p>Description:</p>
            <p>The A/B/C button sends a message to the ISO485 terminal, and the ISO485 received message will be displayed on the screen</p>
        </div>
    </div>
</div>

## Related Link

-  **Datasheet**
   - [ISO485](https://m5stack.oss-cn-shenzhen.aliyuncs.com/resource/docs/datasheet/unit/IS3082W.pdf)

## Schematic

<img src="assets/img/product_pics/unit/iso485/iso485_sch.webp" width="60%">

### Pin Map

<table>
 <tr><td>M5Core(GROVE C)</td><td>U2RXD(GPIO16)</td><td>U2TXD(GPIO17)</td><td>5V</td><td>GND</td></tr>
 <tr><td>ISO485 Unit</td><td>RS485 RXD</td><td>RS485 TXD</td><td>5V</td><td>GND</td></tr>
</table>

## Example

### 1. Arduino

- [Click here to download the Arduino example](https://github.com/m5stack/M5-ProductExampleCodes/tree/master/Unit/ISO485/Arduino/ISO485)

### 2. UIFlow

- [Click here to download the UIFlow example](https://github.com/m5stack/M5-ProductExampleCodes/tree/master/Unit/ISO485/UIFlow)

<img src="assets/img/product_pics/unit/iso485/iso485_Example.webp" width="80%" height="80%">

<el-divider content-position="right">Last updated: 2020-12-11</el-divider>

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