Specifications

18
Figure 2.2.3.1-1 PIC18F2455 - Flash 28-pin High Performance Microcontroller
with USB block diagram, permission granted by Microchip.
An advantage to using this microcontroller would be that it has 1 Kbyte of
memory specifically dedicated for the USB buffer. Therefore, this allows this
sensor to be able to have a USB communication interface. PIC18F also
accompanies 256 bytes of EEPROM data memory. For the communications
interface, as spoken above, it has a USB pin and also a EUSART for a RS232,
RS485, and also a LIN serial interface. PIC18F allows this portable unit to run in
two communication interface, one being serial and the other USB. This would
expand on the difference ways to communicate with other peripherals systems,
storage devices, etc.
Since this portable unit will be low in power, this microcontroller would have a
great solution to. The PIC18F is a nanoWatt device that is sure to supply enough
cpu to the connecting devices. This device as well has unique power-managed
mode which can be effect the system in its performance. Since this device has
four timer modules, the timer1 oscillator, the current flows to an astonishing 1.1
micro amps with 32 khz, and controlling the voltage down to 2 volts. In sleep
mode current goes down to 0.1 micro amps and in idle mode the current flows
down to 5.8 micro amps. This device and family packages two capture, compare,
pulse-width modules.
The interesting fact about this particular PIC18F in regards to the pulse-width
module is that it creates 10 bit resolution output which will lead to an efficient way
to produce the result and also sample data. PIC18F has a programmable