RS485 Shield for Arduino - DFRobot DFR0259

RS485 is an industrial standard for long-distance, anti-interference, and reliable communication. The Arduino RS485 shield, specially designed for the Arduino Uno board. It converts UART/Serial protocol to the RS485 protocol.  This RS485 board allows Arduino talk to industrial devices.

In contrast to RS-422, which has a single driver circuit that cannot be switched off, RS-485 drivers use three-state logic allowing individual transmitters to be deactivated. This allows RS-485 to implement linear bus topologies using only two wires. The equipment located along a set of RS-485 wires is interchangeably called nodes, stations, or devices.
 

1. Integrated a standard RS485 port, a mini RS485 port, RS485 headers

2. Provide the welding areas to make full use of the free space. And more importantly, it's convenient for your DIY design.

3. Switch between automatic mode and manual transmission mode, which expands the scope of application.

4. Besides Tx/Rx interface, there is a switch to block/disable this shield, when Arduino needs to be programmed.

5. Gold immersion PCB. Long pins on the back adapt to most Arduino controllers.

What is RS485?

"RS-485 enables the configuration of inexpensive local networks and multidrop communications links. It offers data transmission speeds of 35 Mbit/s for distances up to 10m and 100 kbit/s up to 1200 m. Since it uses a differential balanced line over twisted pair (like RS-422), it can span relatively large distances up to 1,200 m (4,000 ft). A rule of thumb is that the speed in bit/s multiplied by the length in meters should not exceed 108. Thus a 50-meter cable should not signal faster than 2 Mbit/s." From Wiki.

1. Power module: +5V

2. Module size: 55mmx53mm(2.16"x2.08")

3. 16 digital IO ports (including an I2C interface)

4. 6 analog IO ports and power

5. Operation and programming mode switch

6. Automatic and manual transceiver mode switch (When in manual transceiver mode, the enable end is the 2nd digital IO port)

7. Transceiver indicating LED

8. Standard RS485 interface, mini RS485 interface, and RS485 pins

9. Welding area

10. Reset switch

11. PH2.0 sensor interface for DFRobot RS485 series sensor: URM04 Ultrasonic sensor

1. Wiki (Arduino RS485 Shield)

2. Schematic

1. RS485 Arduino shield     x1