Processors

The main processing unit is a STM32 ARM Cortex-M3 microcontroller that offers 48 general purpose I/O pins. Having a large amount of I/O helps taking care of all the peripherals needed for the system. The microcontroller was over-clocked to 128MHz in order to achieve a decent LCD refresh rate while communicating with other five peripherals. The STM32 also featured a bootloader to load the software, without the need of any expensive programmers.On the wireless node side PIC18F4550 microcontrollers were used to handle wireless packets, read sensors and control devices.

Wireless

Wireless components here!

More wireless!

GSM Network

To enable the system to communicate with devicesoutside the home network, a GSM modem was used.This enables the user to request information about thehouse while away and also control devices. Furthermorein case of an emergency the system also calls the next ofkin.The GSM module is a Telit GM862 modem and itscontrolled through the ARM serial port using ATcommands.

Bluetooth ad-hoc

To help data logging more efficiently a serial Bluetooth module was used. At any time, any data required to be read or logged are sentout through the serial port of the STM32 and via Bluetooth end upinto a terminal on the PC. A terminal can save the data to a file. The data can be organised and plotted using software like Microsoft Excel. The Bluetooth module is the GP-GC021 class 2 by SureElectronics Co., which is a stripped down model that registers only as a virtual com port. Themodule pairs to the host computer like every other Bluetooth device does and provides areliable and flexible gateway for the information. The Bluetooth module has a range ofaround 15 metres.

Sensors

Sensors link

Key pinger 

*missing text