rodi-binary-protocol

A binary protocol to interact with Gary Servin's RoDi (Robot Didáctico inalámbrico).

Clients for Pharo Smalltalk, Ruby and NodeJs are on their way.

Please consider that this protocol is in a very early stage so big changes should be expected.

Install

• Clone this repository.
• Clone the rodi-code repository, you will need this to transfer the server to the robot.
• Get the Arduino compiler (https://www.arduino.cc/en/Main/Software).
• Connect to the RoDI access point. Be sure to set in your machine a static IP address in the proper network (e.g. 192.168.4.2).
• Open the Arduino compiler and load the server/server.ino file.
• Before compiling make sure that you have selected Tools -> Board -> Arduino Pro or Pro Mini and Tools -> Processor -> ATMega168(3.3V, 8MHz).
• Click on "Verify" to compile the server. By this time you should have the compiled program stored in /tmp/build<XYZ>.tmp/server.cpp.hex
• Use the rodi-code tools to transfer the program to the robot by doing rodi-code/programmer/program_rodi.py /tmp/build<XYZ>.tmp/server.cpp.hex

API description

This library implements a binary protocol, where every command is specified by one byte and followed by one or more bytes according to the required parameters (if any).

Sensors

Read the two IR sensors

• Description: Reads the two IR sensors placed at the bottom of the robot.
• Command code: 1
• Parameters: None.
• Returns: Two numbers from 0 to 1024, sent as four bytes (2-bytes each number) in MSB order.

Read left IR sensors

• Description: Reads the left IR sensor placed at the bottom of the robot.
• Command code: 2
• Parameters: None.
• Returns: Number from 0 to 1024, sent as two bytes in MSB order.

Read right IR sensors

• Description: Reads the right IR sensor placed at the bottom of the robot.
• Command code: 3
• Parameters: None.
• Returns: Number from 0 to 1024, sent as two bytes in MSB order.

Read sonar

• Description: Reads the sonar placed at the front of the robot.
• Command code: 4
• Parameters: None.
• Returns: Number from 0 to 100, sent as one byte.

Actions

Turn led on

• Description: Turns the led on
• Command code: 51
• Parameters: None.
• Returns: Nothing.

Turn led off

• Description: Turns the led off
• Command code: 52
• Parameters: None.
• Returns: Nothing.

Move left servo

• Description: Sets the left servo speed to the provided value.
• Command code: 53
• Parameters: The servo speed in the range of [-100, 100]. This number must be sent in one byte and will be interpreted in two's complement.
• Returns: Nothing.

Move right servo

• Description: Sets the right servo speed to the provided value.
• Command code: 54
• Parameters: The servo speed in the range of [-100, 100]. This number must be sent in one byte and will be interpreted in two's complement.
• Returns: Nothing.

Move both servos

• Description: Sets the speed of both the left and right servos.
• Command code: 55
• Parameters: Two numbers defining the servo speeds in the range of [-100, 100]. These numbers must be sent in one byte each and will be interpreted in two's complement.
• Returns: Nothing.

Play tone

• Description: Plays the given frequency in a buzzer. For more details see https://www.arduino.cc/en/Reference/Tone.
• Command code: 56
• Parameters: The frequency of the squared wave that will be generated. This must be sent in a two-byte, which will be interpreted as unsigned, MSB.
• Returns: Nothing.

Clear tone

• Description: Stops playing the sound in the buzzer (if any).
• Command code: 57
• Parameters: None.
• Returns: Nothing.