Firmware and functional test platform developed for a smart controller

[摘要] ENGLISH ABSTRACT: Natural resources are important for human existence. Initiatives to manage resourceseffectively are exercised daily. The consumption of water and electricity increases daily in South Africa, and worldwide, thus the need for exploring new resource savings techniques.The primary electricity supplier of South Africa, Eskom, can not meet the current demand at all times. Not only is South Africa facing a shortage of electricity supply, but, at the time of writing, also a drought that could harm the economy. The Western Cape and the Eastern Cape provinces are especially under pressure by the drought. The Western Cape government implemented water usage limits and it is currently escalated to 87 Lper person per day. The Nelson Mandela Bay municipality, in the Eastern Cape, was on the verge of being declared a drought disaster area in March of 2017. The necessity of saving initiatives are thus evident for South Africa.The Internet of Things is well suited to contribute to these savings initiatives. This thesis forms part of a smart controller (SC) for electric water heaters (EWHs), whichallows the user to monitor water usage and set a control schedule to automatically switchthe EWH on and off. The SC gathers data from EWHs, allowing research to predict optimal heating schedules. This research can also be used to implement a schedulingtechnique to switch an EWH on and off, depending on the national electricity grid load during peak consumption times, whilst still providing the EWH user with hot water on demand.The first development in this thesis is focused on designing and implementing firmwarefor a new SC hardware design. The SC communicates to a central database, with the use of an equipped cellular modem. The firmware consists of two parts, modem firmware and peripheral firmware. The peripheral firmware is responsible for correct actuatorfunction and measuring the sensors accurately. The measurements are aggregated and concatenated into a single report string, which is sent to a cloud based database every minute.The SC forms part of a smart electric water heater controller project, which received funding from the Water Research Council to develop and install SCs in eMkhondomunicipality district in Mpumalanga, South Africa. The SC used for research purposes is upgraded with new hardware, containing a new processor, which lead to the requirementof newrmware. The new hardware was tested in-house by a labourer, which requiredtechnical skills. This test required physical signal injection and result evaluation by thetester. The need to improve this test procedure lead to the second development of this thesis. An automatic test procedure is designed, which consists of test hardware and test software. The implementation of the complete test system is evaluated and the systemefficacy is determined.The research objective to develop and implement firmware for the new SC hardwareis achieved and is implemented on a total of 245 SCs. The data collected, by these SCs, was of such a standard that research could be done on optimisation of heating schedules and provide a means to create awareness of a household's EWH consumption patterns.The second objective to develop and implement a test system was achieved, where the accuracy of the hardware is determined and the test system efficacy showed, during the validation tests, six of the ten tests were successful. The test system would be a benefit tosmall scale production sectors, where uncertified test equipment suface and cost effective test solutions are required.

[发布机构] Stellenbosch University