ActivMedia Robotics
Normally enabled (default was disabled in P2OS), change E_STALL by sending the
AROS command #56. With argument of zero, E_STALL gets disabled. An argument
value of one re-enables E_STALL.
ACCESSORY COMMANDS AND PACKETS Several types of alternative server information packets (SIPs) come with AROS to better
support the ActivMedia Robotics community. On request from the client by a related
AROS command, the AROS server packages and sends one or a continuous stream of
information packets to the client over the HOST serial communication line. Extended
packets get sent immediately after the standard SIP that AROS sends to your client every
SIP milliseconds (typically 100).22
The standard SIP takes priority and gets sent as soon as the communication port is free
and the cycle timer expires. So you may have to adjust the communications baud rate
to accommodate all data packets in the allotted cycle time, or some packets may
never get sent.
Packet Processing
Identical with the standard SIP, all AROS server information packets get encapsulated
with a header (0xFA, 0xFB), byte count, packet type byte, and trailing checksum. It is up
to the client to parse the packets, sorted by type for content. Please consult the
respective client application programming manuals for details.
ARIA, for example, comes with a framework for packet parsing and has an internal
parser for the PSOS/P2OS/AROS packet type 0x3S (S=0-2; aka “standard” SIP), as well as
for some of the extended packets we describe in this section.
Table 8. CONFIGpac contents (AROS v1.5 and later)
LABEL DATA DESCRIPTION
HEADER int Common packet header = 0xfAFB
TYPE byte IDs ENCODERpac = 0x20
BYTE COUNT byte Number of following data bytes
ROBOT TYPE str Typically “Pioneer”
SUBTYPE str Identifies the ActivMedia robot model; e.g. “p3dx”,
SERIALNUM str Serial number for the robot.
4MOTS byte Antiquated (=1 if AT with P2OS)
ROTVELTOP int Maximum rotational velocity; deg/sec
TRANSVELTOP int Maximum translation speed; mm/sec
ROTACCTOP int Maximum rotation (de)acceleration; deg/sec2
TRANSACCTOP int Maximum translational (de)acceleration; mm/sec2
PWMMAX int Maximum motor PWM (500=fully on).
NAME str Unique name given to your robot.
SIP byte Server information packet cycle time
HOSTBAUD byte Baud rate for client-server HOST serial: 0=9.6k, 1=19.2k,
2=38.4k, 3=56.8k, 4=115.2k.
AUXBAUD byte Baud rate for AUX serial port 1; see HostBaud
GRIPPER int 0 if no Gripper; else 1
FRONT SONAR int 1 if robot has front sonar array enabled, else 0
REAR SONAR byte 1 if robot has rear sonar enabled, else 0
LOWBATTERY int In 1/10 volts; alarm activated when battery charge falls
below this value.
REVCOUNT int Current number of differential encoder ticks for a 360
degree revolution of the robot.
WATCHDOG int Ms time before robot automatically stops if it has not
22 You may have to adjust the HOST serial baud rate to accom modate the additional communications traffic.
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