The people at CWAV loaned me one of the USBee RX pods that combines an 18-input logic analyzer, 8-output logic pattern/signal generator, and 2-channel scope in a small package that communicates with a PC via a USB 2.0 connection. I couldn't pass up the opportunity to test this pod with several microcontroller modules, including an ARM mbed and Arduino Uno module. For more information, visit: http://www.usbee.com/rx.html. I recommend this product highly.

I downloaded the software from the CWAV site and installed it and the .NET Framework 4 without any problems. My PC recognized the USBee RX pod as soon as I connected it. The USB driver installation took only a few seconds. Next I opened the manual (264 pages), which the installer placed in the program group to make it easy to find. The introduction explains what the USBee RX pod can do and how to go through the set up of inputs and outputs.

Tests started with monitoring a UART output. A pull-down menu, "Speed and Samples," let me quickly switch to a slower rate that best showed data from the UART. The manual explains how to set up individual logic-analyzer traces to treat an input signals in asynchronous-serial, SPI, I2C, CAN, USB, 1-Wire, and other formats. Users specify characteristics such as number of data bits, bit rate, parity, and the logic-analyzer input channel. The software can display the serial data in binary, decimal, or hexadecimal values, or as ASCII characters. That capability simplifies interpreting the data. During some recent experiments I used hex displays of serial communications to quickly monitor packets sent to and from wireless devices via a UART. There's no other way to effectively troubleshoot and debug serial communications.

But things get even better when you discover the PacketPresented portion of the software that will separate communications into packets that clearly identify addresses, data, checksums, acknowledgements, and other pieces of information in a communication. The PacketPresented definitions use a textual format, so you can define your own for a proprietary packet format.

Two separate trigger blocks, X and Y, in the USBee RX software let users select an analog or a digital input as a trigger based on signal edges. A "while" condition lets them select an optional pattern of bits that must exist, or not exist for the trigger to occur. Then users can use the X-block trigger, the Y-block trigger or combine them in logical AND and OR operations. They also can select Y then X or X then Y. Those trigger options should handle most needs.

The 2-channel scope inputs digitize analog signals at 100 megasamples/sec with a 10-bit resolution. I measured sine-wave signals at 20 MHz with only slight attenuation. CWAV doesn't provide a -3 dB figure for the analog inputs, though. For work up to 10 MHz the USBee RX pod provides good amplitude values. By the way, I recommend a large display for your PC so you can see all of the information. The screens were a bit cramped on the old 19-inch LCD display in my lab. Increasing the display resolution helped me see more.

I used an MCU board to ramp up a DAC output and monitored a digital signal synchronized with the DAC and one unrelated digital input. It was easy to correlate the functions and cursors on the display let me get timing information as well as frequency, duty cycle, and pulse widths. In addition, users can group signals in a bus and observe bus operations.  If the software doesn't do something you need, an API lets you "roll your own" code and manipulate information as needed. The USBee RX manual includes information about the ToolBuilder software and provides two examples, one in C and the other in VisualBasic.

A short review cannot explain all of the features and capabilities of the software, signal generation, and capabilities I didn't have time to test. You can download the manual and the USBee RX code at www.usbee.com/download.htm. The software will display a demonstration screen without the RX pod and you can examine first hand what the software can do.  The test pod has a list price of $US 1945.00 but as of 26 January 2012 had a sale price of $US 1745.  If you do serious mixed-signal troubleshooting and debugging of microcontrollers, the USBee RX pod deserves a close look.  The price might seem high, but after a couple of days on your bench and it will have paid for itself. It's less expensive than other bench instruments with similar capabilities. One point worth noting: The USBee RX does not galvanically isolate signals, so you cannot "float" a device under test--the pod, its attached PC, and your device must share a common ground. You can set logic-level thresholds, though. --Jon Titus