Clayton Gumbrell's mbed-based QRSS-Rx
The topic of wireless communication is more relevant than ever. The technology is used everywhere from vehicles to hospitals to consumer electronics to military systems. Therefore, electronics engineers around the world are devoting their careers to innovating technologies to meet the ever-growing demand for wireless devices.
Since its inception in 1988, this magazine has been publishing articles on wireless technology. Examples include Ed Nisley’s “Digitizing Infrared Signals” (Circuit Cellar 2), Maurizio Ferrari’s “Secrets of Using the DS1209 in an RF Transponder” (Circuit Cellar 41), and Steve Ciarcia’s “Wireless Remote Control of the AVMux” (Circuit Cellar 46). This month we continue the tradition.
On page 14, Clayton Gumbrell describes his QRSS-Rx design. The mbed-based receiver can digitize a small bandwidth of RF signals and send them to a server for processing.
Turn to page 30 to learn how Steve Lubbers built his “KartTracker,” which is a standalone GPS-based timing system used to time racing activities. An LCD operates as a user interface, an integrated accelerometer records G forces, a serial port provides connections to a GPS receiver and a wireless transmitter, and removable flash memory stores data.
Ed Nisley tackles the topics of capacitor self-resonance, GPS technology, RF energy, and data transmission in the first part of his series titled “RFI Bypassing” (p. 38). He presents a radio project featuring SMD capacitors for suppressing RF energy, and he describes test-fixture measurements on isolated capacitors.
As usual, this issue is not devoted solely to its theme. CPUs, power supplies, ADCs, Linux, and protocols are also covered.
On page 24, Alexander Pozhitkov begins a two-part series about the NakedCPU platform. It is designed to provide full access to hardware and a CPU without any OS restrictions while working in the protected mode.
In the first part of his series on building a robust power supply, George Novacek described how to make a power supply operate properly when the primary power distribution bus voltage is lower than nominal. This month he explains what happens when it encounters an abnormal surge voltage (p. 44).
On page 52, Robert Lacoste details how to work with high-speed ADCs. The article is intended to demystify the process of using high-speed converters effectively.
Another topic that needs demystification is embedded Linux, which is why Bob Japenga has been covering the subject in his ongoing series “Getting Started with Embedded Linux.” This month he addresses various licensing issues you’ll face as you work with Linux (p. 60).
Columnist Jeff Bachiochi wraps up this issue with the article “Multi-Serial Protocol Tool” (p. 64). As you’ll see, it’s fairly easy to build a multi-serial protocol tool designed to connect from a USB host an I2C, SPI, RS-232/422/485, or Dallas 1-Wire format.