28023 Parallax Inc, 28023 Datasheet - Page 8

• Manufacturer Part Number: 28023
• Description: CONTROLLER 16SERVO MOTOR CONTROL
• Manufacturer: Parallax Inc

Specifications of 28023

• Lead Free Status: Contains lead
• Main Purpose: Power Management, Motor Control
• Embedded: Yes, MCU, 8-Bit
• Utilized Ic / Part: BASIC Stamp® or Javelin Modules
• Primary Attributes: Servo Controller
• Secondary Attributes: 16 channels
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: 28023PAR

Revision List
Hardware
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Rev A
90 degree rotation, 4 uSec resolution, 1-2 mS pulses, 8 bit PWM, 15 possible ramp values, position
polling, and a serial interface at 38k4 Baud. You could daisy-chain this unit, but the fact that there was
only one comm connection made it difficult. The bulk of the silkscreen was on the PCB bottom. Glitch
(due to comms) on Ch0 and Ch8 removed.
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Rev B
The connectors were changed slightly to accommodate easier to implement daisy-chain scheme. The
silkscreen was corrected so that pertinent info was on pcb top. The serial interface was expanded to
support either 2400 Baud or 38k4 Baud.
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Rev B
The firmware was enhanced to support 16-bit pwm, 180 degree rotation, 2uSec resolution, and 63 ramp
rates. Serial code was optimized to accept messages faster than the BS2 could send them.
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Rev B
Report position bug in the firmware was found and corrected. Specifically, when polling a servo position,
the position of the last servo written to was reported regardless of the requested channel number.
Rev B
Some conditions caused interrupt contention within the PSoC chip which in turn caused a small amount of
glitch on some of the output channels. This glitch caused some servos to oscillate when they should
have been still. The PWM channels were restructured such that interrupt contention no longer affects
PWM performance. The output glitch has been reduced from +-2uS to less than +- 100 nS.
Note: your PSC is re-programmable.
for a free firmware upgrade. Your only cost is the shipping fee.
Liability Disclaimer
Parallax, Inc. is not responsible for special, incidental, or consequential damages resulting from any
breach of warranty, or under any legal theory, including lost profits, downtime, goodwill, damage to or
replacement of equipment or property, and any costs of recovering, reprogramming, or reproducing any
data stored in or used with Parallax products.
8
Firmware
1.0
1.1
1.2
1.3
1.4
Parallax, Inc. • Parallax Servo Controller – Rev B ver 2.4 (#29023) • 1/2005
(Only Beta units released)
released March 1
released March 16
released April 19
released January 12
If your PSC firmware is not current, you may send it in to Parallax
th
st
, 2004
, 2004
th
, 2004
th
, 2005