Description: Our friends over at LinkSprite have made this nifty little RS485 Shield, now you will be able to have a communication port for your field bus directly connected to your Arduino! Even though the RS485 is sometimes thought as an “archaic” protocol, it will allow up to 32 devices to communicate through the same data line over a cable length of up to 4000ft with a maximum data rate of 10Mbit/s. Those aren’t bad numbers!
This version of the RS485 shield removes the optional DB9 connector bay and adds a second 2-pin screw terminal and the ability to choose two pins from your Arduino’s D0 to D7 as Software Serial Ports to communicate with the shield.
This shield does come without its headers separate so a small amount of soldering will be required before attaching it to your Arduino device.
Based on 5 ratings:
I bought this to connect to a Love Controls temperature controller ModBus interface and had it up and running within less than an hour. The documentation on their website (linksprite’s) leaves a little to be desired though. Lackluster documentation is the only reason I’m not giving it a five. The board is beautiful and the quality is top notch.
It works great and does exactly as i expected.
I had to connect two Arduinos to two legacy motor controllers that used MODBUS protocol on RS485. This worked well only after a few learning pains on getting the serial settings correct (this was the fault of the motor controller not this great device). I have two of these running in the field. Using these saved me $280. over buying special RS485 to RS232 converters for the legacy motor controllers.
Only 4 stars as it does not support Arduino Leonardo and Mega (and possibly others) for RX communication because apparently not all pins on these boards support change interrupts (needed for software serial if you still want to be able to program the arduino board though built in serial port on pin0/pin1) but that’s not mentioned anywhere. Pins that support RX for these boards can be found here: https://www.arduino.cc/en/Tutorial/SoftwareSerialExample This RS485 shield can only use RX/TX on arduino pins 0->7 (jumpers D0-D7 on shield) and since we still want to be able to program our arduino while the shield is attached, selecting other pins as RX/TX won’t work. My workaround: i placed a wire between the two RX jumpers on the shield and inserted the other end in digital port 8 on arduino (see here: https://www.dropbox.com/s/s1k1bdytmtnioy8/20170222_000743.jpg?dl=0). In software you initialize pin 8 instead of pin 6 as RX: SoftwareSerial mySerial(8,7); Probably not the best solution but it should do for now as i already got four of these…
I wanted to use this to make a Modbus RTU RS485 network so I bought two of them. I tried every possible jumper combination on this shield and it doesn’t work. Every Modbus read (function 3) command gets check sum errors. I removed the shield and wired my Arduinio Uno TX/RX (and transmit pin 9) to a bread board with a Maxim MAX485-CPA IC and the communications work perfectly. Waste of money.
Hi, Please contact us about your issue. We may be able to help you with a return. https://www.sparkfun.com/returns