In a nutshell, this is how the system operates. The owner makes a first call to perform task number 1 as memorized by the system. In case task 2 needs to be performed, the owner calls a second time. Here, a fixed phone disconnects the first call after relaying the signal from call number 2. If tasks number 3, 4, 5 need to be performed, the owner calls 3, 4 or 5 times successively and the fixed phone keeps on disconnecting previous calls and relaying incoming calls to perform the appropriate task.
As of the tea maker, it was modified from a small deep-frying machine. A container is positioned at the base of the fryer which has an electrical coated coil, while milk is poured in a separate container. Tea leaves are also placed in a much smaller independent container hooked to the milk container. To activate the tea maker, Simon Mwaura places five successive calls to the fixed phone. The motherboard gets the message and starts the tea making process. The milk container tilts and pours the milk and the leaves into a container and, after about 4/5 minutes, a light turns on and a sound detonates. The tea is ready and the container tilts and pours it into a thermos-like container.
Simon Mwaura is a Kenyan electrician and inventor who has developed a mechanism that can activate several automated gadgets from an ordinary mobile phone. The system allows its owner to open or lock doors remotely or to receive an alert if an intruder opens a door. It can also switch on/off lights and start a tea maker remotely. Simon Mwaura uses a mobile phone to send orders to a control panel that looks like a maze made of several wires, sensors, electric motors, switches, etc. This control panel is what the inventor calls the "motherboard".
Sources: standardmedia.co.ke - Simon Mwaura - Maker Fair Africa