SHT7x (including SHT71 and SHT75) is Sensirion’s family of relative humidity and temperature sensors with pins. The sensors integrate sensor elements plus signal processing in compact format and provide a fully calibrated digital output. A unique capacitive sensor element is used for measuring relative humidity while temperature is measured by a band-gap sensor. Example of this sensor usage with ATmega8 is given in this article.
All microcontroller developers for debugging and device control use serial communication via a computer (or other device). The most commonly used serial communication is RS232. Ten years ago, every computer was equipped with a serial port, but today it is uncommon on PC platforms and almost non-existent in laptops.
IR data transfer is very often used in devices around us. Every TV, audio system, Air Conditioner uses IR remote controllers. Every device that receives IR commands have one simple IR receiver component inside it. It is usually covered with IR filter to reduce noise from daylight. This is not necessary when making IR remote control project with microcontroller.
This article will give basic overview of iButton functionality and usage. Example of iButton usage with complete source code can be read in article iButton AVR readout example project used with DS1990R-F5. The iButton is a computer chip enclosed in a 16mm thick stainless steel can. Because of this unique and durable container, up-to-date information can travel with a person or object anywhere they go. The steel iButton can be mounted virtually anywhere because it is rugged enough to withstand harsh environments, indoors or outdoors. It is small and portable enough to attach to a key fob, ring, watch, or other personal items, and be used daily for applications such as access control to buildings and computers, asset management, and various data logging tasks.