Microcontrollers

A variety of microcontrollers have been used in wireless sensor networks. Some Radio Transceivers have a microcontroller integrated on the same chip. In no particular order:

Atmel
Most of the current wireless sensor network devices are designed around Atmel microcontrollers. The devices have all the basic features needed to manage a WSN device. Besides, such popularity is due to the fact that the Berkeley Motes and their clones are developed on Atmel architecture. TinyOS and related software are originally made for Atmel AVR devices.

Examples of WSN devices with Atmel microcontrollers:
 * BTnode (ETH Zurich) (http://www.btnode.ethz.ch)
 * Mica Mote (Crossbow) (http://www.xbow.com/Products/productsdetails.aspx?sid=62)

Cypress
Cypress offers a nice range of microcontrollers. One of the key features is reconfigurable internal components and pins. They also provide developers with free software that greatly simplifies microcontroller programming. This is especially important when you are dealing with USB.

As far as I know, Cypress M8C microcontrollers are the only microcontrollers with analog outputs.

Microchip
Microchip Technology manufactures PIC microcontrollers famous for their versatility and relatively low cost. PICs range from tiny low-power 8-pin devices that could drive a remote control to quite sophisticated chips that have digital signal processing capabilities, a range of hardware interfaces, and basic wireless communication features.

The company provides developers with a well documented and supported set of microcontroller prototyping, programming and debugging tools.

Examples of a sensor network device based on a PIC microcontroller:
 * Hoarder Board - Open Hardware Design (MIT Media Lab) (http://vadim.oversigma.com/Hoarder/Hoarder.htm)
 * PicoCrickets(Montreal, Canada) (http://www.picocricket.com)

(Microchip's rfPIC chip combines a microcontroller with a ASK / FSK radio transmitter).

Panasonic
Panasonic also offers a range of microcontrollers suitable for sensor network devices.

Examples:

Nordic
Nordic Semiconductor, a manufacturer of radio transceivers often used in wireless sensor networks, has released a family of chips (example nRF24E1) that combine microcontroller, radio transceiver, and ADC.

Examples:
 * Ambient Systems mesh networks (Netherlands) (http://www.ambient-systems.net/ambient/technology-features.htm)

NXP
NXP Semiconductors develops advanced microcontrollers.

Silicon Laboratories
Silicon Laboratories (SiLabs) manufactures a range of 8051 mixed-signal microcontrollers.

TI
The TI MSP430 has long had the least power consumption of all microcontrollers currently available.

However, "Innovative Techniques for Extremely Low Power Consumption with 8-bit Microcontrollers" by Arne Martin Holberg and Asmund Saetre claims that the "PicoPower" Atmel AVR ATmega165P has a lower "Power Save Current Consumption with 32 kHz Running" than the MSP430.