garbage is fallen down by foreign objects. Besides that, the system did not provide a user interface for the user to track the garbage bins’ condition and location in real time, the software shall be imposed to achieve the internet of things. If the previous proposed project are implemented with these elements, the system will be more rounded.
On the other hand, the current proposed system also lack of the elements that the previous proposed project has, namely the self-describing ability. The self-describing ability is necessary so that to make sure that the user throw the garbage accordingly to the respective garbage bin. However, this will also incur a lot of cost such as the implementation of RFID and various monetary objects. The ideal solution would be to implement web camera sensor to the respective smart garbage bins. The web camera sensor will detect and recognize the pattern of each type of waste. The web camera is to remember the pattern and characteristic of the respective waste. For example, the web camera will detect the glass when it captures something that is reflective. Each of the smart bin is embedded with a web camera, the camera will scan the waste and determine whether to open the cap of the garbage bin before the user throw the waste. If the technology and maturity of the web camera sensor is strong enough to detect each of these wastes, it would be a greater alternative as compared to RFID tag which applied to each of the waste. This approach will helps to save a lot of resources and monetary object.
The project “IoT-Based Smart Garbage System for Efficient Food Waste Management”, which was done by a team of Korean scholars, from Chung-Ang University, Seoul, Republic of Korea (Hong, Park, Lee & Jeong 2014) is doing well in food waste reduction
However, the proposed smart garbage system which is based on RFID technology needs resident to have RFID card in order to discard the garbage. The RFID card should be hold anytime at any moment by the local residences. These will incur a lot of issues, for instance, forgetting to bring the RFID card, then the resident wouldn’t be able to throw the garbage immediately when it is in a critical situation. According to figure above, the payment of each discarding can cause server overload to the central server (administration server). This is due to the complex discarding process of RFID-based SGS, user may suffer from the waiting process of the scanning and data processing of the RFID process. In addition, RFID systems or related item can be disrupted quite easily, as RFID implement electromagnetic spectrum, for instance WiFi and cellular phones, they are vulnerable and can be jammed at any time. This will cause inconvenience for the consumers. Furthermore, RFID tags can be accessed without even the consumer’s knowledge. “Since the tags can be read without being swiped or obviously scanned (as in the case of barcode), anyone with an RFID card can accidentally read the tags that are inside their clothes and other consumer products without consumer’s knowledge.”
For the third project, despite the conveniences of using Global System Mobile Communication (GSM), this will incur a lot of monetary issues and also the issue for the database and usage. Based on the proposed product, the Subscriber Identity Module (SIM) card was deployed to solve the connecting issue. However, application of SIM card to each smart garbage system will incur some issues. First, need to consider all the garbage bins and apply the SIM card to each of the garbage system, this will in turn increase the budget of the data subscriptions dramatically. The second issue is the SIM card generally requires a lot of energy to operate, since the SIM card needs to communicate with the courier server consistently. This is not ideal because the smart garbage system is supposed to operate for years and so on.
To solve all these issue, the interrupt services of the platform (Arduino) can help. By using the interrupt subroutine of the proposed platform, the battery life of the proposed system will be prolonged. For example, the SIM card sends the data to the courier server
only when there is something disposed into the garbage bin. For the rest of time, the system is in idle mode, hence, to save a lot of energy incurred by the SIM card.
Besides that, several wireless communication technologies have been investigated and studied. To determine which type of technology will be used throughout the project.
According to (Dar, Bakhouya, Gaber & Wack 2010), the general wireless communication technologies include Bluetooth, ZigBee, Global System Mobile Communication (GSM), WiMax, Infrared wireless (IR) and WLANs (a/b/g/n).
Table 2.1: Comparison between Wireless Communication Technologies
N.O Name Data Rate Mobility Range Power
Based on the table, conclude that either GSM or Zigbee is more applicable for this proposed project. Due to the limitations of other technologies, there are not appropriate for the application of this project, for instance, WLANS, as shown in the table, its mobility is limited and the range of coverage is quite small, which is only 50 – 100 meters. Besides that, its power consumption is high despite its latency is fairly low.
The forth project which was proposed by the Indian scholars has its own advantages and disadvantages by using the technologies mentioned (WiFi and UART) in the previous section. The main advantages of the system that they proposed is that it provides a reliable and stable communication route for the data to be sent from WAPU to the Central Monitoring Station. The cabled communication between WAPU and Central Monitoring Station will guarantee that the data sent from WAPU will be received from the Central Monitoring Station, which is insusceptible to the factors like electromagnetic disruption which is often occurred in the wireless communication.
However, this method of communication also causes some inconveniences while transmitting the data from WAPUs to the Central Monitoring Station. In real life, it is not always possible to setup all WAPUs to 1 Central Monitoring Station using the cable connections, due to the fact that the sensors are usually in the place where that is in far distance away from the Central Monitoring System. Hence, using the UART communication between the WAPU and Central Monitoring Station is not very reliable when the distance is too far away. Furthermore, the system’s sensors are connected to the WAPU via the WiFi connection. The same issue applies to this case, it is the distance that is too short. As discussed in the previous section, the maximum range of WiFi cannot even exceed 1 KM (based on current WiFi technology). However in real life, the distance between the garbage bins and the WAPU is always far in distance, typically in term of Kilometers.
Hence, a better options shall be considered, that are RF (radio frequency) communication for the communication between sensor nodes and WAPU and Internet Communication via UDP or TCP for the communication between WAPU and the Central Monitoring
Station. By using these 2 types of communication, the long range communication between each component and node can be realized.
In the fifth proposed project which was done by Parkask & Prabu. There exist several strengths and weaknesses. The strengths of he proposed system is that the smart garbage system are using the 8051 microcontroller. 8051 microcontroller is famous for its low power consumption. As the IoT-based garbage system is basically be placed in external location. External location scenario requires the continuous service, which means the battery of the system must have higher capacity and fault tolerance, yet small in size.
With the low-power consumption characteristic of the 8051 microcontroller, the proposed system can continue to service even for a longer period. On the other hand, the proposed system provides a graphical website for the management company to monitor the condition of all garbage bins in the respective cities. Hence, improve the garbage management of the company. This website can be accessed anywhere and anytime (Parkash & Prabu 2016).
However, there exist some issues in this proposed system. To detect the level of the garbage, appropriate sensors must be attached to different part of the garbage bin. Type of sensors will affect the quality of detecting the garbage level in the garbage bin. In this proposed system, IR Sensor is used.
There exist various types of approaches to detect the level of garbage of the garbage bin by using different kind of sensors. Each sensor has its own strengths and weaknesses.
Section below shows some sensors that are implemented in the previous research and proposal that were done by the other researchers and scholars:
Possible sensors that are used to detect the level of garbage in bin:
- IR Sensor
- Ultrasonic Sensor - Weight Sensor
IR Sensor - For the garbage detection, IR sensor can be used. It gives the level of the garbage in the dustbin. It provides information about the level of the garbage in the dustbin. Hence, Infrared (IR) sensor is use for garbage detection. IR sensor radiates light,
which is invisible to the human eye because it is at infrared wavelengths, but it can be detected by electronic devices (Kurre 2016). The IR sensor is act as level detector .The output of level detector is given to the microcontroller. The output consists of information of garbage levels of respective dustbins.
Figure 2.6: Principle of Operation of IR Sensor There are a few strengths of using the IR sensor. These are:
• Less expensive
• Low power consumption
However, there are few weaknesses of using the IR sensor. These are:
• Not accurate ranging
• Narrow beam width
• Cannot be used while exposed in sun
Ultrasonic Sensor – Ultrasonic Sensor use sound instead of light for ranging as compared to IR Sensor, so Ultrasonic Sensors can be use outside in bright sunlight. These sensors are amazingly accurate, although their performance maybe weakens by some absorbing materials, like a sponge (Eric 2015).
Figure 2.7: Principle of Operation of Ultrasonic Sensor Advantages of using Ultrasonic Sensor:
• Accurate ranging measurement
• Works under sun exposure
• Good performance either inside or outside room Disadvantages of using Ultrasonic Sensor:
• May become inaccurate when encounter adsorbing obstacle
• Generally expensive than other similar sensors
Weight Sensor – Weight sensor is place below the garbage bin to sense the weight of the garbage bin. The LOAD cell will continuously will continuously give the weight readings in voltage format (Prajakta , Kalyani & Snehal 2015).
Advantage of using Weight Sensor:
• Well settle below the garbage bin, tightly embedded as compared to attached to cap.
Disadvantages of using Weight Sensor:
• Inaccurate measurement, cannot detect the level
Based on the discussion above, the proposed system is using IR sensor. Due to the limitation of using IR sensor (as mentioned above), the performance of smart garbage system (SGS) can be deteriorate. This will incur many issues, for instance, the garbage bin is empty but it reports condition as full to the central server (administration server).
The solution to this issue is to implement the system using Ultrasonic Sensor. Ultrasonic Sensor provides a more reliable detection when it comes to garbage monitoring system.
As it detects the level of the garbage bin by emitting the ultra sound and the reflected ultrasonic will feedback to the ultrasonic sensor, instead of using infrared led light, which could be malfunctioned while exposed in sunlight.