The design and construction process of the Household Waste Tracking System ultimately changed the final implementation of the system significantly. Between the first and final designs of the project many things changed but the primary tasks of the system remained the same.
The major differences in the overall design of the system include changes to the micro-controller, the data storage system, the data transmission method and the web interfacing of the project. In the final implementation of the system, waste weight measurement is still evaluated using a load cell, although the system now utilizes an off-board analog to digital converter and amplifier board to return a highly accurate value. The system still uses radio frequency identification (RFID) to identify tags that are embedded inside trash bins.
Top level devices and connectivity block diagram
The waste bin measurement, like the original implementation still occurs through a load cell, but in the final implementation an analog to digital converter and amplifier are used to convert the value from the load cell to a usable value. Since the differential voltage provided by the load cell is very small, in the mere millivolt range, the analog to digital converter onboard the Arduino would provide a very small range of resolution to read the weight, a feature that would end up providing inaccuracies that would cost waste management companies and their customers countless dollars.
Since a primary goal of the final system was to provide location data along with specific customer waste information, the system required a GPS location. With the addition of a GPS/ GSM module the system was able to acquire the location of each individual waste reception. In the event that this identification will fail, the household waste cataloging system will record the GPS location of the trash retrieval sight and use that as a reference in determining the identity of the trash and owner of the trash bin, based on historical retrievals of that location. If a bin is habitually unable to be read, the trash company may either service the waste-bin or notify the owner of the bin that they need to replace their waste bin. Although GPS is highly reliable since it’s based on highly reliable satellites, occasionally the system may have an internal error making the module inaccessible, or in the event the GPS antenna is covered, the system will still be able to acquire the location of a waste reception through the GSM network, using GPRS technology. Although GPRS locations are not as accurate as GPS location, they will still give waste management companies insight into the amount of waste received in a specific area which can be used for big data.
When weight, identification and location data have all been acquired, the system then stores the data on a Secure Digital (SD) card. This creates a hard copy of all data collected along a route. In the event that the system is unable to wirelessly transmit the data back to a server, this hard copy will allow provide redundancy and reliability for customer information.
Once all customer waste information has been collected, the system wirelessly transmits the information through GSM data to a web based display. The household waste tracking system accomplishes this by using a GPS/GSM break out board. Using a simple Http post the system transmits individual user information to a storage server upon individual waste bin retrieval.
