iRobot CREATE - OPEN INTERFACE Manual page 11

Send IR Opcode: 151
This command sends the requested byte out of low side
driver 1 (pin 23 on the Cargo Bay Connector), using the
format expected by iRobot Create's IR receiver. You must
use a preload resistor (suggested value: 100 ohms) in
parallel with the IR LED and its resistor in order turn it on.
• Serial sequence: [151][Byte Value]
• Available in modes: Safe or Full
• Changes mode to: No Change
• Send IR data byte 1: Byte value to send (0 - 255)
Example Schematic
100 Ohms
iRobot Create Open Interface (OI) Specification
Data Bytes: 1
+5V
IR LED
180 Ohms
LD1
Song Opcode: 140
This command lets you specify up to sixteen songs to the OI
that you can play at a later time. Each song is associated
with a song number. The Play command uses the song
number to identify your song selection. Each song can
contain up to sixteen notes. Each note is associated with a
note number that uses MIDI note definitions and a duration
that is specified in fractions of a second. The number of data
bytes varies, depending on the length of the song specified.
A one note song is specified by four data bytes. For each
additional note within a song, add two data bytes.
• Serial sequence: [140] [Song Number] [Song Length]
[Note Number 1] [Note Duration 1] [Note Number 2]
[Note Duration 2], etc.
• Available in modes: Passive, Safe, or Full
• Changes mode to: No Change
• Song data byte 1: Song Number (0 – 15)
The song number associated with the specific song. If
you send a second Song command, using the same song
number, the old song is overwritten.
• Song data byte 2: Song Length (1 – 16)
The length of the song, according to the number of
musical notes within the song.
• Song data bytes 3, 5, 7, etc.: Note Number (31 – 127)
The pitch of the musical note Create will play, according
to the MIDI note numbering scheme. The lowest musical
note that Create will play is Note #31. Create considers
all musical notes outside the range of 31 – 127 as rest
notes, and will make no sound during the duration of
those notes.
• Song data bytes 4, 6, 8, etc.: Note Duration (0 – 255)
The duration of a musical note, in increments of 1/64th
of a second. Example: a half-second long musical note
has a duration value of 32
Data Bytes: N+,
where N is the number
of notes in the song
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