Pioneer 3TM, 2TM manual Input Output I/O, User I/O

ActivMedia Robotics Operating System

modifications to the robot's heading are done on the client side, as supported in the latest versions (1.3 and later) of ARIA.

To enable the gyro, you must set the HasGyro FLASH parameter to 1 using the AROScf tool (see next chapter). Set it to 0 if the gyro isn't attached. Then to acquire gyro data, send the GYRO client command #58 with integer argument of one; zero disables the gyro SIP. The gyro SIP is stopped upon client disconnection or controller reset, too.

AROS collects the gyro rate and temperature readings at the maximum rate of once every 25 milliseconds and reports each of these values to the client, when enabled, in the GYROpac SIP that gets sent just before the standard Server Information Packet every sInfoCycle, typically every 100ms. GYROpac consists of a count byte of the rate and temperature data pairs accumulated since the last cycle (typically 4 for a 100ms cycle time), followed by that number of rate/temperature integer/byte pairs.

Gyro rates are 10-bit integers of value 0-1023. When not moving, the rate is centered around 512 or so, depending on the gyro's temperature and other calibration factors which drift with use and should be corrected on the fly. Values below that center point indicate counter-clockwise rotational rates; values above the resting center measure clockwise rotational rates.

Table 12. GYROpac SIP contents

LABEL	BYTES	CURRENT VALUE	DESCRIPTION
HEADER	2	0xFA, 0xFB	Common header
BYTE COUNT	1	xx	Varies
TYPE	1	0x98	Packet type
N PAIRS	1	x	Number of gyro data pairs
FOR N PAIRS
RATE	2	varies 0-1023	Gyro rate
TEMPERATURE	1	varies 0-255	Gyro temperature
CHECKSUM	2	varies	Computed checksum

INPUT OUTPUT (I/O)

Your AROS-based robot comes with a number of I/O ports that you may use for sensor and other custom accessories and attachments. See Appendix A for port locations and specifications. Some I/O states and readings appear in the standard SIP and may be manipulated with AROS client commands. There also is an IOpac SIP for convenient access to all of your robot’s I/O.

User I/O

The User I/O connector on the H8S controller contains eight digital input and eight digital output ports, as well as an analog-to-digital (A/D) port.23 The bit-mapped states of the sixteen digital ports and analog port automatically and continuously appear in the standard SIP, in their respective DIGIN, DIGOUT, ANALOG bytes. When not physically connected, the digital input and A/D port values may vary and change without warning.

Use the AROS client command number 30 to set one or more of the eight DIGOUT ports on the AROS controller. Electrically, the ports are digital high (1) at ~5 VDC (Vcc) and low

(0)at ~0 VDC (GND). DIGOUT uses a two-byte (unsigned integer) argument. The first byte is a mask whose bit pattern selects (1) or ignores (0) the state of the corresponding bit in the second byte to set (1) or unset (0) the digital output port.

23Many of these ports are used by the Gripper accessory. Alternative I/O also is available.

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