Circuit Cellar’s April issue is nothing less than an embedded programming toolbox. Inside you’ll find tips, tools, and online resources to help you do everything from building a simple tracing system that can debug a small embedded system to designing with a complex system-on-a-chip (SoC) that combines programmable logic and high-speed processors.
Article contributor Thiadmer Riemersma describes the three parts of his tracing system: a set of macros to include in the source files of a device under test (DUT), a PC workstation viewer that displays retrieved trace data, and a USB dongle that interfaces the DUT with the workstation (p. 26).
Riemersma’s special serial protocol overcomes common challenges of tracing small embedded devices, which typically have limited-performance microcontrollers and scarce interfaces. His system uses a single I/O and keeps it from bottlenecking by sending DUT-to-workstation trace transmissions as compact binary messages. “The trace viewer (or trace “listener”) can translate these message IDs back to the human-readable strings,” he says.
But let’s move on from discussing a single I/0 to a tool that offers hundreds of I/0s. They’re part of the all-programmable Xilinx Zynq SoC, an example of a device that blends a large FPGA fabric with a powerful processing core. Columnist Colin O’Flynn explores using the Zynq SoC as part of the Avnet ZedBoard development board (p. 46). “Xilinx’s Zynq device has many interesting applications,” O’Flynn concludes. “This is made highly accessible by the ZedBoard and MicroZed boards.”
Our embedded programming issue also includes George Novacek’s article on design-level software safety analysis, which helps avert hazards that can damage an embedded controller (p. 39). Bob Japenga discusses specialized file systems essential to Linux and a helpful networking protocol (p. 52).
Other issue highlights include projects that are fun as well as instructive. For example, Jens Altenburg added an MCU, GPS, flight simulation, sensors, and more to a compass-controlled glider design he found in a 1930s paperback (p. 32). Columnist Jeff Bachiochi introduces the possibilities of programmable RGB LED strips (p. 66).