Page 439 - Hacking Roomba

420 Appendix C — iRobot Roomba Open Interface (ROI) Specification

iRobot® Roomba® Open Interface (ROI) Specification

Safe Command opcode: 131 Number of data bytes: 0 Serial sequence: [137] [Velocity high byte] [Velocity low byte]
[Radius high byte] [Radius low byte]
This command puts the ROI in safe mode. The ROI must be in
full mode to accept this command. Drive data bytes 1 and 2: Velocity (-500 – 500 mm/s)
Note: In order to go from passive mode to safe mode, use the Control Drive data bytes 3 and 4: Radius (-2000 – 2000 mm)
command. Special cases: Straight = 32768 = hex 8000
Serial sequence: [131] Turn in place clockwise = -1
Turn in place counter-clockwise = 1
Full Command opcode: 132 Number of data bytes: 0
Example:
Enables unrestricted control of Roomba through the ROI and
turns off the safety features. The ROI must be in safe mode to To drive in reverse at a velocity of -200 mm/s while turning at
accept this command. This command puts the ROI in full mode. a radius of 500mm, you would send the serial byte sequence
[137] [255] [56] [1] [244].
Serial sequence: [132]
Velocity = -200 = hex FF38 = [hex FF] [hex 38] = [255] [56]
Power Command opcode: 133 Number of data bytes: 0
Radius = 500 = hex 01F4 = [hex 01] [hex F4] = [1] [244]
Puts Roomba to sleep, the same as a normal “power” button
press. The Device Detect line must be held low for 500 ms to
wake up Roomba from sleep. The ROI must be in safe or full
mode to accept this command. This command puts the ROI in
passive mode. Motors Command opcode: 138 Number of data bytes: 1
Controls Roomba’s cleaning motors. The state of each motor is
Serial sequence: [133]
specified by one bit in the data byte. The ROI must be in safe
or full mode to accept this command. This command does not
Spot Command opcode: 134 Number of data bytes: 0 change the mode.
Starts a spot cleaning cycle, the same as a normal “spot” Serial sequence: [138] [Motor Bits]
button press. The ROI must be in safe or full mode to accept this
command. This command puts the ROI in passive mode. Motors data byte 1: Motor Bits (0 – 7)
Serial sequence: [134] 0 = off, 1 = on
Bit 7 6 5 4 3 2 1 0
Clean Command opcode: 135 Number of data bytes: 0
Motor n/a n/a n/a n/a n/a Main Vacuum Side Brush
Starts a normal cleaning cycle, the same as a normal “clean” Brush
button press. The ROI must be in safe or full mode to accept this
command. This command puts the ROI in passive mode.
Example:
Serial sequence: [135]
To turn on only the vacuum motor, send the serial byte
Max Command opcode: 136 Number of data bytes: 0 sequence [138] [2].
Starts a maximum time cleaning cycle, the same as a normal
“max” button press. The ROI must be in safe or full mode to
accept this command. This command puts the ROI in passive Leds Command opcode: 139 Number of data bytes: 3
mode.
Controls Roomba’s LEDs. The state of each of the spot, clean,
Serial sequence: [136]
max, and dirt detect LEDs is specified by one bit in the first data
byte. The color of the status LED is specified by two bits in the
Drive Command opcode: 137 Number of data bytes: 4 first data byte. The power LED is specified by two data bytes, one
for the color and one for the intensity. The ROI must be in safe
Controls Roomba’s drive wheels. The command takes four data
bytes, which are interpreted as two 16 bit signed values using or full mode to accept this command. This command does not
twos-complement. The first two bytes specify the average velocity change the mode.
of the drive wheels in millimeters per second (mm/s), with the Serial sequence: [139] [Led Bits] [Power Color] [Power Intensity]
high byte sent first. The next two bytes specify the radius, in
millimeters, at which Roomba should turn. The longer radii make Leds data byte 1: Led Bits (0 – 63)
Roomba drive straighter; shorter radii make it turn more. A Drive Dirt Detect uses a blue LED: 0 = off, 1 = on
command with a positive velocity and a positive radius will make Spot, Clean, and Max use green LEDs: 0 = off, 1 = on
Roomba drive forward while turning toward the left. A negative
radius will make it turn toward the right. Special cases for the Status uses a bicolor (red/green) LED: 00 = off, 01 = red, 10 =
radius make Roomba turn in place or drive straight, as specified green, 11 = amber
below. The ROI must be in safe or full mode to accept this
command. This command does change the mode. Bit 7 6 5 4 3 2 1 0
LED n/a n/a Status (2 bits) Spot Clean Max Dirt Detect
Note: The robot system and its environment impose restrictions that may
prevent the robot from accurately carrying out some drive commands. For Power uses a bicolor (red/green) LED whose intensity and color
example, it may not be possible to drive at full speed in an arc with a large
radius of curvature. can be controlled with 8-bit resolution.
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