The design and construction of a high-end watt hour meter requires a microcontroller as the central control element. Most watt hour meter projects will require that you design an electrical circuit interface between the microcontroller, an AC to DC converter, a filter or an integrated circuit specifically designed to measure AC current and voltage. There are a manufacturers who provide complete microcontroller kits for the design, development and construction of watt hour meters.
E-Bikes projects or, battery powered bicycle projects, involve the design of a controller system that can be based on an 8-bit microcontroller. The microcontroller is used to control the speed of the bicycle motor in response to a signal from an electronic throttle.
The microcontroller can also be programmed and interfaced to bicycle lights, horns and radios. The microcontroller can be programmed to perform these functions when specific buttons on the control panel are pressed. The microcontroller can also be designed to switch in solar cell charging circuits to charge the E-bike's battery or to switch the motor's power source from the battery to the pedals.
High-end battery chargers often include a microcontroller in the design. The microcontroller will automatically detect when the voltage level of a battery is below an acceptable level and then automatically connect the battery to a charging circuit.
The microcontroller is also used to detect when the battery is fully charged and then to disconnect the battery charging circuit. For a high-end battery charger, the microcontroller can be used to set the rate at which the battery charges. Batteries that are charged with low levels of current will, in general, have a longer life than batteries that are charged quickly.
Microcontrollers are often used to generate the text and images sent to a display screen, such as a LCD (liquid crystal display) screen found on cell phones and other portable electronic devices. Many microcontrollers have LCD drivers built into them for just that purpose. Many manufacturers provide prewritten microcontroller code designed specifically for text display tasks.
Because so many electronic products require that text be sent to a display, a microcontroller project that involves interfacing to a LCD display is a good choice for a beginner.
Motor controllers, built with microcontrollers are used in the design of household appliances, such as vacuum cleaners, sewing machines and washing machines. Because appliances often operate under different loads, for example in a washing machine or dryer, microcontrollers are used to keep the motor turning at a constant speed even when the weight the motor must move changes.
Microcontrollers can be used not only just to control the motor in these appliances but also receive and respond to button settings on the appliance. The microcontroller is also often programmed to display messages and activate lights on the appliance's control panel. These messages might inform the user, for example, how much time is left in a washer's spin cycle.