Analysis/Procedure:
There are many type of sensors currently being used nowadays. In this project, I need to find a suitable sensor that suitable for the speedometer. This components is the most important part. The sensor must detect the narrow and thin needle of the speedometer. My idea of the position of the sensor which will be placed on the speedometer display:
Below is the suitable sensor that I think could integrate with the speedometer.
- Proximity Sensor
- A proximity sensor is a sensor able to detect the presence of nearby objects without any physical contact. A proximity sensor often emits an electromagnetic field or a beam of electromagnetic radiation (infrared, for instance), and looks for changes in the field or return signal. The object being sensed is often referred to as the proximity sensor's target. Different proximity sensor targets demand different sensors. For example, a capacitive photoelectric sensor might be suitable for a plastic target; an inductive proximity sensor always requires a metal target. The maximum distance that this sensor can detect is defined "nominal range". Some sensors have adjustments of the nominal range or means to report a graduated detection distance. Proximity sensors can have a high reliability and long functional life because of the absence of mechanical parts and lack of physical contact between sensor and the sensed object.
- One of the application of this sensor is on a modern smart phone. For example, if there is an outgoing or incoming call on a smart phone and a person will start moving the cellphone towards his or her ear to listen to the other person, the device’s proximity sensor detects that the phone is very close to his or her face. The proximity detector signals the motherboard to disable the phone’s touch-sensitive display to prevent the person inadvertently activating an icon on the screen with his or her face. When the person move the phone away from your head, the proximity sensor detects the change and reactivates the touch-sensitive display.
In term of this project with the proximity sensor, if the proximity sensor detects a needle crosses the sensor it will send a signal to the PIC and automatically sends an SMS through the GSM modem.
