Introduction

Multiplexer is a multi protocol converter which is composed by multiple interfaces for using controller communication. Multiplexer supports conversion interfaces among USB, TTL, RS232, RS485, and allows to have one input and multiple outputs. It's more convenient for many kinds of controllers to communication.

Specification

Power Supply

Supply Voltage is 5V ,and is divided into two way.

PIN Function Description

Points to note:

Indicator: POWER:power indicator AR->BT: The interface in A as input,the interface in B as output BR->AT: The interface in B as input, the interface in A as output TEL0070_PIN_EN.png

Tutorial

Requirements

Sample descripition: The multiplexer board achieve USB to TTL, micro USB interface in A as input and the TTL interface in B as output. The operation is same for USB to 232 and 485.Similarly, the reverse converter B to A is also feasible,such as 232 to USB,485 to USB, TTL to USB.

Connection Diagram

  1. Plugin Micro USB cable to multiplexer board. The "POWER" LED turns on at the same time.
  2. Driver Installation: V1.0 uses FT232R USB to TTL chip, please click here to download Driver. V2.0 uses CH340 USB to TTL chip, please [click here to download Driver](https://github.com/Arduinolibrary/DFRobot_FireBeetle_ESP8266_DFR0489/raw/master/CH340 Driver.zip)

Note: CH340 driver is free to install for most of Windows OS, if you find there is no COM Port in Device Manager, please download the driver and install it.

CH340 Driver After the driver installed completed, please open Control Panel -- Device Manager in your PC. You will see a new port.

  1. According to the following connection diagram,connect it.
  2. Plugin the A to B USB to UNO

TEL0070_UNO.png

Sample Code

void setup()
{
  Serial.begin(115200);
}
void loop()
{
  if(Serial.available()){
  Serial.write(Serial.read());
  }
}

Expected Results

We need a serial monitor for monitoring data. There're lots of good tools like putty,CoolTerm and so on.In this case, we choose CoolTerm to do this.

Please set the baud rate to 115200 bps and com port.Back to the main interface, click Connection--Send String, the following dialog will open.

BlueTooth20.jpg You can send the string in this dialog. The string received can be showed in the other port(UNO port).

BlueTooth21.jpg

Thus far,you achieve the function USB to TTL. However, you can test reversed converter based on this function, being B to A converter. You only need to change the UNO code. You will see the change that coolterm will receive data from UNO.

Refer to the test code:

void setup()
{
  Serial.begin(115200);
}
void loop()
{
  Serial.print("Hello,DFRobot!");
  Serial.println();
  delay(500);
}

Other Reference Connection

1.TTL to 232 converter

TEL0070_2321.png

PIN RS-232
1 DCD
2 RXD
3 TXD
4 DTR
5 GND
6 DSR
7 RTS
8 CTS
9 RI

2.USB to 485 converter

TEL0070_to_485.png

FAQ

Q&A Some general Arduino Problems/FAQ/Tips
A For any questions, advice or cool ideas to share, please visit the DFRobot Forum.

More Documents

DFshopping_car1.png Get Multi USB/RS232/RS485/TTL Converter V2.0 from DFRobot Store or DFRobot Distributor.

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