A new, better Openbench Logic Sniffer

The venerable Openbench Logic Sniffer has long been a popular logic analyzer: it's cheap, capable and entirely open source. Unfortunately the project was abandoned long ago, so no new features were ever added. The one major problem with the OLS was always its limited available memory: it has no memory chip on the board, using only the small amount of memory available on the FPGA to store samples. Its slow, PIC-based USB interface made it impossible to use a streaming architecture, like the fx2lafw devices.

Enter the Saanlima Pipistrello: an inexpensive but very capable FPGA development board. It has a newer Spartan-6 FPGA, 16MiB flash, 64MiB DRAM and an FTDI-based USB interface. It also comes with lots of ports: HDMI, audio, Micro-SD, PMOD, and 48 GPIO pins in a Papilio Wing configuration. The board is completely open source: schematics and Eagle design files are available under the CC-BY-SA 4.0 license. The board itself sells for $155 at the Saanlima Store.

A buffer wing is also available. This protects the FPGA with 5V-tolerant transceivers. Highly recommended: I destroyed many unbuffered pins on my OLS board long ago.

The original OLS verilog code couldn't use DRAM for storage, so the Saanlima folks adapted it. Proper edge triggers were also added to the FPGA code, something that was cumbersome on the OLS. They also contributed a sigrok driver, which has been merged into libsigrok. Thanks, Magnus!