Connecting the evaluation board to Arduino Due
This article is for the Arduino lovers in the crowd. It describes hardware configuration to control an LL-RLP-20 or LL-RXR-27 evaluation board using an Arduino DUE.
Once you get the hardware setup, please refer to this article to start your software development.
Why use Arduino Due?
The LL-RLP-20 or LL-RXR-27 module is designed to be controlled over UART. This means the Arduino must dedicate a serial interface to control the Symphony Link module.
Unfortunately, the most common Arduino boards (like the UNO) have only one serial interface (digital pins 0 and 1). This interface is used by the Arduino to communicate with a PC and it is the interface typically used to write firmware to the Arduino from the Arduino IDE. This makes it difficult to control a Symphony Link module without substantial modifications to the Arduino platform.
The Arduino Due, on the other hand, possesses several serial interfaces, and therefore it can easily be used to control a Symphony Link module without the need to modify Arduino's default use of pins 0 and 1 for programming, monitoring, etc.
Setting up the Due
There are slight differences in connecting the various versions of the LL-RLP-20 or LL-RXR-27 evaluation board to the Arduino Due. The following pictures show wire diagrams to highlight the critical connections.
Connecting a Rev. 4 evaluation board
Don't forget to remove the USB-UART jumper, which is normally installed on the Rev. 4 board. Otherwise, you will power the eval board's USB-UART bridge. This causes contention on the serial port used to control the module.
Connecting a Rev. 5 evaluation board (LL3B50)
Connecting a Rev. 6 evaluation board (LL3B60)
With the Rev. 6 eval board, we've tried to make it easier to connect the board to various platforms. You'll need to make sure the 0-ohm resistors circled in purple are installed. Sorry to make you do some soldering!