Intro: Remind Me, Alight
This project is done by Fong Jia Yi from Singapore Polytechnic, with Mr Teo Shin Jen as our project supervisor.
Have you miss your bus stop because you overslept? Here is the solution to counteract this problem.
The reason why I created this invention because as a bus and train enthusiast, I noticed many problems faced by many public transport users. One of the very common problems is that some commuters have overslept and they missed their stop. In some cases, they lost their way as they were in some unfamiliar places when they woke up and the bus or train service has ended. Therefore, I decided to come up with the device to wake commuters up at their desired stops.
(Overall concept sketch of invention above)
Step 1: Things Needed
The bus stop alarm system is designed for commuters who travelled on long bus journeys. The prototype of this system is simple, it comprises of Radio Frequency (RF) 315 MHz transmitter and receiver, two sets of Arduino UNO microcontroller and a piezo electric buzzer.
The reason why RF is chosen is because the radio frequency transmitter and receiver set is a cheaper method of data communication as each set costs less than 10 dollars. Also, as a single RF transmitter is able transmit data to multiple receivers, only one RF transmitter is needed for each bus stop. This further reduces the overhead of the system.
Furthermore, it has a better accuracy of detecting the bus stops as compared to GPS as the transmitter on the bus stops basically transmit data to receivers on the bus.
Step 2: Wiring Scheme
Here is the schematic diagram of overall invention.
Step 3: Hardware for RF Transmission Module
To be convenient, create an Arduino shield by using the stripboard. As you can see in the pictures, I solder a female header each for the RF transmitter and receiver as well as the Piezo electric buzzer. By doing that, a faulty unit can be easily plug out and replaced without the need of de-soldering. On top of that, I have added a molex header to interface the piezo electric buzzer and the bracelet with the receiver shield.
Step 4: Piezo Electric Buzzer
The piezo electric buzzer will have to be wired to a separate piece of stripboard as the buzzer has to be attached a bracelet (can be anything for the user to put on). For my case, I have 3D printed a bracelet with a slot for the piezo electric board.
Step 5: Software
For prototyping purposes, I am making use of Serial Monitor to input the user's data.
To begin with, the user will key the identification number of a bus stop on a user interface (Eg. Touchscreen tablet, Arduino Serial Monitor (For prototyping purpose). The bus stop will be where the user wished to wake up and from there, the Arduino UNO will store the user’s data.
The transmitter unit which is made up of an Arduino UNO and a RF transmitter is placed at bus stops along the bus routes. (Refer to Figure 2). The RF transmitter will then transmit the identification number of the bus stop. The data will be captured by the RF receiver and data will be processed by the receiver unit. (Refer to Figure 3). The receiver will check if the bus stop number from transmitter unit matches that of the user’s data. If the bus stop number match, the piezoelectric buzzer at the receiver end will produce a sound to wake the user up.
Here are the codings for the Arduino UNO to transmit data using RF.
A sample coding from the Piezo Electric buzzer can be found here:
Step 6: Conclusion
My final prototype will be using an ATtiny85 instead of an Arduino Uno as this could reduce the space needed for building this portable alarm. In addition, other than using the RF communication for building this portable alarm. I am also planning to use the RF communication for other applications.
For example, this form of communication can be used to provide a cheaper and yet more accurate arrival time for the bus services in Singapore. This time round, instead of having a pair of transmitter and receiver, there will be multiple transmitter and single receiver. On top of that, a Wi-Fi module will be used to send data over the net. The transmitter will be placed in the bus and the receiver will be installed at the bus stops. When the bus arrives at the bus stops, the transmitter will send the data (i.e. Bus Service, Estimated number of passengers, Bus registration number) to the receiver and receiver will connect to Wi-Fi and report on the location updates of the bus.
Video of Demo: https://www.youtube.com/watch?v=0YYQowmxEkE&feature=youtu.be