Download TCSP0222

Schematic

Aliases have source prefix followed by signal
name
 Ex:

PWR_3.3V
Schematic simplified into several smaller circuits
 Microcontroller
Circuit [UC]
 Reprogramming Circuit [RP]
 “Button” Circuit [BTN]
 802.11 Wireless Compact Flash Circuit [CF]
 External Communication [COM] & LCD Circuit [LCD]

Both use RS232
 Power

Circuit [PWR]
These will each be discussed (serially)
Schematic:
MicroController Circuit [UC]

Parts Included
 Microcontroller
 8.0

[ATmega2561]
MHz Xtal
Functional Purpose
 “Brain”
of the design
 Source and destination of essentially all logic

Selection Rationale
 ATmega2561


Lots of input pins
Lots of flash
Schematic:
MicroController Circuit [UC]
Schematic:
ReProgramming Circuit [RP]

Parts Included
 AVR
ISP [5x2 header]
 JTAG [5x2 header]
 Reset pushbutton

Functional Purpose
 Allow

debugging & reprogramming of μC after ass’y
Selection Rationale
 It
probably (and unfortunately) won’t work the first
time
Schematic:
ReProgramming Circuit [RP]
Schematic:
BuTtoN Circuit [BTN]

Parts Included
 PLD

[GAL16V8]
Functional Purpose
 Button

5x2:1 MUX’s
Selection Rationale
 Due
to scanning nature of program
debouncing should not be necessary
Schematic:
BuTtoN Circuit [BTN]
Schematic:
802.11 wireless Compact Flash Circuit [CF]

Parts Included
 CF
Wireless Card [NL-2511CF] (and
connector)

Functional Purpose
 802.11

wireless
Selection Rationale
 Smallest
 Cheapest
 Easiest
Schematic:
802.11 wireless Compact Flash Circuit [CF]
Schematic:
external COMmunication & LCD Circuit [COM], [LCD]

Parts Included
 Digital↔RS232
Converter [MAX3232]
 Output & 2x ezLCD-001 Headers

Functional Purpose
 External

and on-device display
Selection Rationale
 RS232

reduces number of pins on uC
2 pins per device = 4 pins
 RS232
protocol is easy and standardized
Schematic:
external COMmunication & LCD Circuit [COM], [LCD]
Schematic:
PoWeR Circuit [PWR]

Parts Included
 Battery
recharger
 Voltage regulator
 Battery meter uC ATD input

Functional Purpose
 All

related to power – see above
Selection Rationale
 Battery
recharger tested and known to work
 Voltage regulation is necessary
 Battery meter is also necessary [added PSSC]
Schematic:
PoWeR Circuit [PWR]
PCB Layout:
Placement of Parts
PCB Layout:
Microcontroller [uC]
PCB Layout:
ReProgramming Circuit [RP]
PCB Layout:
BuTtoN [BTN]
PCB Layout:
802.11 Wireless CompactFlash [CF]
PCB Layout:
external COMmunication & LCD Circuit [COM], [LCD]
PCB Layout:
PoWeR circuit [PWR]
PCB Layout:
Mostly Routed