PACmate20 Braille Display

The Freedom Scientific PACmate 20 is a 20-cell braille display with two pushbuttons over each cell, and two 'whiz wheels' (mousewheel-type wheels) on either side of the braille area. It connects to a PC or other device via USB, and can be attached to the PACmate notetaker to integrate them into one device.

Notable Chips

Chip	Chip Function	Use in Product
C8051F320	Microcontroller w/ USB	Brains of the display, talks to the PC/device natively over USB.
LM358	Op-amp	Don't know
TLC555	Timer	Near large cap, small caps, and inductors. May be part of the HV charge pump?

USB Descriptors

Configuration descriptor:
Total length:           0020
Number of Interfaces:   01
Configuration value:    01
Configuration string:   00
Attributes:             80   [Device doesn't have own power, can't generate remote wakeups]
Maximum power usage     FA   [500mA]

Interface descriptor:
Interface number:       00
Alternate:              00
Endpoints:              02
Class:                  FF   [Vendor Specific]
Subclass:               00   [Ignored: Class FF]
Protocol:               00   [Ignored: Class FF]
Interface string:       00

Endpoint descriptor:
Endpoint address:       01   [10000000: OUT endpoint 1]
Attributes:             02   [01000000: Bulk]
Maximum packet size:    0040 [64 bytes]
Polling interval:       00   [Ignored: Not isochronous or interrupt type]

Endpoint descriptor:
Endpoint address:       82   [10000010: IN endpoint 1]
Attributes:             02   [01000000: Bulk]
Maximum packet size:    0040 [64 bytes]
Polling interval:       00   [Ignored: Not isochronous or interrupt type]

Images