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# 1.14 FLEXCOM RS485

This example application shows how to use the FLEXCOM module in RS485 mode.

## Description

This example connects two boards through the RS485 interface.

One board acts as the transmitter, and the other acts as the receiver.

## Downloading and Building the Application

To clone or download this application from Github, go to the main page of this repository and then click Clone button to clone this repository or download as zip file. This content can also be downloaded using content manager by following these instructions.

Path of the application within the repository is apps/flexcom/flexcom_rs485/firmware.

To build the application, refer to the following table and open the project using its IDE.

Project Name | Description
--- | ---
sam_9x75_curiosity.X | MPLABX project for SAM9X75 Curiosity Development Board
sam_9x75_curiosity_pro.X | MPLABX project for SAM9X75 Curiosity Pro Development Board

## Setting Up AT91Bootstrap Loader

To load the application binary onto the target device, we need to use at91bootstrap loader. Refer to the at91bootstrap loader documentation for details on how to configure, build and run bootstrap loader project and use it to bootstrap the application binaries.

## Setting Up the Hardware

The following table shows the target hardware for the application projects.

Project Name | Description
--- | ---
sam_9x75_curiosity.X | SAM9X75 Curiosity Development Board
sam_9x75_curiosity_pro.X | SAM9X75 Curiosity Pro Development Board

### Setting Up SAM9X75 Curiosity Development Board

Additional hardware required:

- Connect https://www.microchip.com/en-us/development-tool/atrs485-xpro to the board using wires
- Connect the Debug USB port on the board to the computer using a micro USB cable

Setting up the board:

- Connect a programming cable from JTAG connector J12 on board to programmer(J-32 Debugger)
- Connect programmer(J-32 Debugger) to computer using a micro USB cable
- Connect the USB port J1 on board to the computer using a micro USB cable (to power the board)
- The hardware setup requires two boards, one acting as the Host and the other as the Client
- Connect the RX485-XPRO to the mikroBUS socket on the board using wires, following the table below

  | ATRS485 J100 | mikroBUS 1 | SAM9X75
  --- | --- | --- | ---
  UART_TX IO0 | 14 | MOSI | PC22 FLEX3_IO0
  UART_RX IO1 | 13 | MISO | PC23 FLEX3_IO1
  UART RTS IO4 | 5 | CS | PC24 FLEX3_IO4
  3.3V | 20 | 3.3V | 3.3V
  GND | 2 or 19 | GND | GND

### Setting Up SAM9X75 Curiosity Pro Development Board

Additional hardware required:

- Connect https://www.microchip.com/en-us/development-tool/atrs485-xpro to the board using wires
- Connect the Type-C USB port J1 on board to the computer using a Type-C USB cable (to power the board)

Setting up the board:

- Connect a programming cable from JTAG connector J64 on board to programmer(J-32 Debugger)
- Connect programmer(J-32 Debugger) to computer using a micro USB cable
- The hardware setup requires two boards, one acting as the Host and the other as the Client
- Connect the RX485-XPRO to the mikroBUS 2 socket on the board using wires, following the table below

  | ATRS485 J100 | mikroBUS 2 | SAM9X75 CPRO
  --- | --- | --- | ---
  UART_TX IO0 | 14 | MOSI | PC22 FLEX3_IO0
  UART_RX IO1 | 13 | MISO | PC23 FLEX3_IO1
  UART RTS IO4 | 5 | CS | PC24 FLEX3_IO4
  3.3V | 20 | 3.3V | 3.3V
  GND | 2 or 19 | GND | GND

## Running the Application

1. Open the Terminal application (Ex.:Tera term) on the computer.
2. Connect to the USB Serial COM port and configure the serial settings as follows:
   - Baud: 115200
   - Data: 8 Bits
   - Parity: None
   - Stop: 1 Bit
   - Flow Control: None
3. Build and Program the application using its IDE.
4. One board acts as the transmitter, and the other acts as the receiver.

   This is defined by the user.

Rev: E