A single chip wireless sensor (1) comprises a microcontroller (2) connected by a transmit/receive interface (3) to a wireless antenna (4). The microcontroller (2) is also connected to an 8 kB RAM (5), a USB interface (6), an RS232 interface (8), 64 kB flash memory (9), and a 32 kHz crystal (10). The device (1) senses humidity and temperature, and a humidity sensor (11) is connected by an 18 bit .SIGMA..DELTA. A-to-D converter (12) to the microcontroller (2) and a temperature sensor (13) is connected by a 12 bit SAR A-to-D converter (14) to the microcontroller (2). The device (1) is an integrated chip manufactured in a single process in which both the electronics and sensor components are manufactured using standard CMOS processing techniques, applied to achieve both electronic and sensing components in an integrated process.