Arduino UNO with RS-485 (DFR0259) Pin Assignments
clsanchez77 2020-09-15 01:00:41 1327 Views3 Replies Hey all. I am looking to build an Arduino 7 channel TDS meter using the Whitebox Tentacle Shields; these use I2C (SCL & SDA) and require no other pins in this I2C mode.
The two features I would like to add to this project is an RS-485 interface and a 2x16 LCD screen w/keypad. The products I have in mind for this are:
RS-485 Shield (DFR0259)
2x16 LCD Screen w/Keypad (DFR0009 or DFR0374)
The documentation on the screen/keypad uses pins 4 -10 & A0. I cannot find documentation on the RS-485 that specifically defines the pin assignments. All I see is that it uses serial communications. The description states it converts UART to RS-485, which tells me this is pins 0 & 1. However, the sample code makes references to Pin 13 for communication (Pin 2 for mode). The schematic is not really helping me either, but perhaps I am just missing it.
Can anyone help me clarify the required pin assignments?
Thanks
The two features I would like to add to this project is an RS-485 interface and a 2x16 LCD screen w/keypad. The products I have in mind for this are:
RS-485 Shield (DFR0259)
2x16 LCD Screen w/Keypad (DFR0009 or DFR0374)
The documentation on the screen/keypad uses pins 4 -10 & A0. I cannot find documentation on the RS-485 that specifically defines the pin assignments. All I see is that it uses serial communications. The description states it converts UART to RS-485, which tells me this is pins 0 & 1. However, the sample code makes references to Pin 13 for communication (Pin 2 for mode). The schematic is not really helping me either, but perhaps I am just missing it.
Can anyone help me clarify the required pin assignments?
Thanks
2020-09-18 08:32:02 Thanks for clarifying that. Looking at the sample code again, I see what you mean. Pin 13 was just used in the sample code and not needed to use the card.
A side question. If I am communicating from the Arduino as a slave device to a PLC (master) via a RS-485 port using ASCII. The transmission from Arduino to PLC will be a single HEX string that will include 9 numeric values concatenated, once a second. The PLC will send a ASCE code to wake-up or hibernate the Arduino sensors. Is the RS-485 shield needed? Can the Arduino handle the serial ASCII transmissions natively? clsanchez77
A side question. If I am communicating from the Arduino as a slave device to a PLC (master) via a RS-485 port using ASCII. The transmission from Arduino to PLC will be a single HEX string that will include 9 numeric values concatenated, once a second. The PLC will send a ASCE code to wake-up or hibernate the Arduino sensors. Is the RS-485 shield needed? Can the Arduino handle the serial ASCII transmissions natively?
clsanchez77 
