RoboRemote is an Arduino project for a Bluetooth based remote controller. It uses a 4-axis joystick, several push buttons, a potentiometer and an 1602 LCD to control self build robots. For communication, 2 HC-05 Bluetooth modules are required. The Sketch is running on an Arduino Pro Mini with an ATmega328(5V, 16MHz).
A Tutorial for building RoboRemote is shown on YouTube:
part 1 - preparing the hardware: https://www.youtube.com/watch?v=xHsCnpfgwEI
part 2 - schematic and wiring : https://www.youtube.com/watch?v=I3VOlUwofhE
part 3 - programming and test : https://www.youtube.com/watch?v=15aVeGGLiDI
Here is the schematic of RoboRemote. It is explained in the videos mentioned in the tutorial.
- 1x Arduino Pro Mini
- 1x FTDI-Adapter for USB-to-Serial communication
- 2x HC-05 Bluetooth modules
- 1x 1602 LCD with I2C interface
- 1x 4-axis Joystick with 10K Ohm potentiometers
- 7x 12mm push button switches
- 4x LEDs (diffent colors)
- 4x 270 Ohm resistors
- 3x 1K Ohm resistors
- 3x 1,8K Ohm resistors
- 2x 4,7K Ohm resistors
- 1x 10K Ohm resistor
- 1x 10K Ohm potentiometer
- 1x on-off switch
- 1x 9V battery clip
- 1x 6x4cm universal prototype PCB
- 1x 3x2cm prototype PCB with strips
- 4x M3 screws and nuts
- 2x M3x12mm hexagonal standoff pillars
- 1x 40pin 2.54mm right angle single row male header
- 1x 40pin 2.54mm single row male header
- 1x 40pin 2.54mm single row female header
- 1x 2mm heat shrink tube, 20cm
- 2x 2pin Dupont connector
- 4x 3pin Dupont connector
- 1x 5pin Dupont connector
- 20x female Dupont jumper wire terminal connector pins
- 0.75mm wires, diverse colors
RoboRemote_HW_Test is a small Sketch for the Arduino Pro Mini to test the wiring and the functionality after the RoboRemote controller has been build. It will print the button states and the potentiometer values to the Serial output. LEDs will be blinking and the LCD will show a welcome message.
RoboRemote_HC05_Terminal is a Sketch for an Arduino to test and configure the HC-05 Bluetooth modules. This sketch can be used independently of RoboRemote to configure 1 HC-05 module as a slave device and 1 HC-05 module as master.
To configure a HC-05 module it must be connected to an Arduino temporary.
Be aware that the BT pins RX and EN/KEY or pin34 of the Bluetooth module
are not 5V tolerant and need a voltage divider between the BT module and the Arduino!
For each pin, where a voltage divider is needed, a 1K resistor is connected between the Arduino pin and the BT pin and another 1K8 or 2K resistor is connected from the BT pin to GND.
BT pins TX and STATE can be connected directly to the Arduino.
Make the following connections between the HC-05 (BT) and an Arduino:
- BT VCC to Arduino 5V
- BT GND to Arduino GND
- BT TX to Arduino pin 2 (no need for voltage divider)
- BT RX through a voltage divider to Arduino pin 3
- BT STATE to Arduino pin 4 (no need for voltage divider)
- BT EN/KEY or pin34 through a voltage divider to Arduino pin 5
The wiring is shown in the following schematic picture:
The BT STATE pin may be connected with an additional 10K pull-down resistor to GND. This will give the Arduino a stable input signal but it is not required for the following configuration tasks.
Now both HC-05 modules can be configured using the Sketch RoboRemote_HC05_Terminal. They will be given different tasks: 1 HC-05 module will be configured in slave mode, the other in master mode.
The HC05 slave module is the receiver from RoboRemote and will be placed in the robot which should be controlled.
The HC05 master module is the transmitter and is part of the RoboRemote Bluetooth based remote controller.
The HC05 slave module for the controlled robot is configured as follows:
- set the slave role for the HC-05 module:
AT+ROLE=0 - configure the desired communication speed: ie.
AT+UART=38400,0,0 - set a remote name for the module:
AT+NAME=RoboRemote - define a PIN for secure access: ie.
AT+PSWD=1234
The HC05 master module for RoboRemote is configured as follows:
- set the master role for the HC-05 module:
AT+ROLE=1 - configure the same communication speed as for the slave: ie.
AT+UART=38400,0,0 - set the same PIN as for the slave: ie.
AT+PSWD=1234 - set connection mode for authorized devices only
AT+CMODE=0 - set inquire access mode, max 5 devices in 9s
AT+INQM=0,5,9 - initialize SPP
AT+INIT - get list of devices in range
AT+INQ - ask for name or specified device
AT+RNAME?xxxx,yy,zzzzzz - pair with specified device
AT+PAIR=xxxx,yy,zzzzzz,9 - set BT address
AT+BIND=xxxx,yy,zzzzzz - connect with device
AT+LINK=xxxx,yy,zzzzzz
After this setup, devices will connect automatically when powered on if they
are not in AT command mode. If AT command mode was selected, the master can
pair with its slave device with the command AT+INIT.
RoboRemote-Controller is the final Sketch for the RoboRemote Bluetooth based remote controller. When powered on, it connects to the pre-configured HC-05 slave module and displays the connection state by powering on the blue LED. While connected, this Sketch will poll the state of all push button switches and read out all potentiometer values. All these informations are packed into a transfer packet and is transmitted to the RoboRemote-Receiver.
In version 1, the LCD will only show the connection process and after that the transmitted packet count.
RoboRemote-Receiver is a Sketch with the HC05 slave module to show that a connection with the RoboRemote-Controller is established. For demonstrating purposes, all data received from the RoboRemote-Controller is printed to the Serial output.
This Sketch can be used as a basis, of how to embedd the HC05 slave module into your own robotic projects.
RoboRemote is written by Andreas Trappmann from Trappmann-Robotics.de. It is published under the MIT license, check LICENSE for more information. All text above must be included in any redistribution.
Version 2.0 - 05.05.2021
- Added a configuration menu for HC-05 master and slave modules
- Added direct binding to accellerate link of Bluetooth modules
Version 1.1 - 19.04.2020
- Added Sketch "RoboRemote_HC05_Terminal" for HC05 Bluetooth module setup.
- Added Sketch "RoboRemote-Controller" for RoboRemote Bluetooth Controller.
- Added Sketch "RoboRemote-Receiver" as a demo receiver for the RoboRemote Bluetooth Controller.
Version 1.0 - 19.04.2020
- Published Sketch "RoboRemote_HW_Test" for basic Hardware testing.