Unable to Decipher Pin Numbers for RX/TX on Sensor Shield

Projects Programming
1

I am currently writing a program to control two servos on an Arduino device via Bluetooth serialization. To my understanding, to achieve Bluetooth communication between an Arduino and a Bluetooth Module (in this case I'm using HC-05), you would use Universal Asynchronous Receive Transmit (UART) serial communication. Most sample programs I see on this use digital pin 0 for RX and digital pin 1 for TX by default to establish Bluetooth serial connection. I imported the Arduino SoftwareSerial library into my program and created an object from the SoftwareSerial class, which according to Arduino documentation, "allows serial communication on other digital pins of the Arduino, using software to replicate the functionality". The object instantiation that I am referring to is written below:

SoftwareSerial SerialBLE(0, 1); // RX, TX

I am using the UART pins on a RobotGeek Sensor Shield (which attaches on top any standard Arduino compatible board), but I am not exactly sure what pins to parameterize inside of the SoftwareSerial object, since the pins on the RobotGeek Sensor Shield differ slightly from the Arduino pins commonly used in Bluetooth example code. I checked in with RobotGeek technical support and they suggested that I take a look at this link to their documentation (http://learn.robotgeek.com/robotgeek-101-1/183-getting-started-with-robotgeek-wiring.html), specifically the section titled "Special Pins". I believe that they are hinting that I should attach my jumper cables (for RX and TX) to digital pins 0 and 1 instead of the UART pins RX-0 and TX-1. If this is true, should I attach each of my jumper cables to the Signal (S) pin of both DIO-0 and DIO-1 and parameterize 0 and 1 in my program?

Special Pins.jpg
Special Pins.jpg900×900 180 KB

2

Can't quite help you but RX and TX are the hardware serial pins and it is useless to put a software serial on those pins. The bluetooth module will interfere with your uploads as well.

Look at the software serial example and take it from there.

3

All the sensor shield is providing is a few more connection to each of the pins, arranged in a slightly more organized manner. They still map one-to-one to the original pins and as such, the use of pins D0 and D1 are still going to be Rx and Tx for the USART. As suggested in #1, if you choose to use the USART to communicate with the Bluetooth, you'll have problems with uploading your sketch without disconnecting BT. What is most commonly done is to select two unused pins of SoftwareSerial and use those with BT. That leaves the USART available for upload and communicating with you PC.

4

Ah ok, so you are saying that I should either unplug the Bluetooth Module before sketch uploads to the Arduino or choose pins other than the UART pins at 0 and 1, so that I may not suspend sketch uploads to the Arduino and so I can the USB to TTL converter to monitor serial communication between the Arduino and my PC (if I choose to do so)? Also, when you say disconnect the Bluetooth Module, do you mean disconnect the RX and TX pins from the Arduino board or to actually remove the Bluetooth Module from the circuit, or would either work?

5

Disconnecting the leads would be sufficient. I use SoftwareSerial (my bastardized version) with Bluetooth all the time, no problem. Leave the on board USART alone and let it do its thing. Communicating with BT is only at 38400 and is quite easily handled by the soft UART.