Specifications

7.3. HARDWARE DESIGN
considering these attributes, it was considered it the ideal solution. The
antenna is attached to the sides of the enclosure with double-sided tape.
7.3.2 Processor
Selection Criteria
When considering the system processor, the following features should be
considered:
Power Consumption In order to maximise battery life under mains power
failure conditions, the chosen processor should support power saving
modes and generally have a low power consumption.
Operating Voltage This determines the level shifters which will be required
(if at all) to interface to other digital devices.
Operating Speed The device needs to be sufficiently fast to process, store
and upload the data faster than real-time to ensure that no data is lost.
RAM Capacity There should be sufficient work-space for all required variables,
data rec ord arrays and system states storage.
Program Storage Capacity The program will include human-readable status
messages which must be stored along with the executing program.
Thus, sufficient space should be allowed f or all these messages, the
program itself and s pace for future expansion.
Non-Volatile Storage System settings and recorded data should be stored
in non-volatile memory to ensure system recovery from a power outage.
If the chosen process or does not provide non-volatile storage, an external
memory should be added.
on-board Peripherals Timers are required for creation of delays, analogue
to digital converters for system health monitoring and communication
ports for use with the G SM module, system status reporting and connection
to other modules.
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