sigrok - cross-platform, open-source logic analyzer software with protocol decoder support

sigrok logo

I'm happy to finally announce an open-source (GNU GPL), cross-platform (Linux, Mac OS X, FreeBSD, Windows, ...) logic analyzer software package myself and Bert Vermeulen have been working on for quite a long time now: sigrok (it groks your signals).


I originally started working on an open-source logic analyzer software named "flosslogic" in 2010, because I grew tired of almost all devices having a proprietary and Windows-only software, often with limited features, limited input/output file formats, limited usability, limited protocol decoder support, and so on. Thus, the goal was to write a portable, GPL'd, software that can talk to many different logic analyzers via modules/plugins, supports many input/output formats, and many different protocol decoders.

The advantage being, that every time we add a new driver for another logic analyzer it automatically supports all the input/output formats we already have, you can use all the protocol decoders we already wrote, etc. It also works the other way around: If someone writes a new protocol decoder or file format driver, it can automatically be used with any of the supported logic analyzers out of the box.

Turns out Bert Vermeulen had been working on a similar software for a while too (due to exactly the same reasons, crappy Windows software, etc.) so it was only logical that we joined forces and worked on this together. We kept Bert's name for the software package ("sigrok"), set up a SourceForge project, mailing lists, IRC channel, wiki, etc. and started working.

Overview, Features

You can get the lastest sigrok source code from our main git repository:

  $ git clone git://

Here's a short overview of sigrok and its features as of today. The software consists of the following components:

  • libsigrok, a shared library written in C, which contains the general infrastructure for handling logic analyzer data in a streaming fashion.
    sigrok logic analyzer collection 2011
    It also contains the individual hardware drivers which add support for various logic analyzers. Currently supported hardware includes: Saleae Logic, CWAV USBee SX, Openbench Logic Sniffer (OLS), ZEROPLUS Logic Cube LAP-C, ASIX Sigma/Sigma2, ChronoVu LA8, and others. Many more devices are on our TODO list (and we already own them), it's just a matter of time to reverse engineer the USB protocols and implement a driver for them.

    Thanks ASIX for being open and helping with the ASIX Sigma driver, and many thanks to ChronoVu for being open as well and providing information about the ChronoVu LA8 protocol! Thanks to Håvard Espeland, Martin Stensgård, and Carl Henrik Lunde (who contributed the ASIX Sigma driver), Sven Peter and "Haxx Enterprises"/bushing (for contributing the ZEROPLUS Logic Cube LAP-C driver, ported from their zerominus tool). Also, thanks to Daniel Ribeiro and Renato Caldas who worked on the Link Instruments MSO-19 driver (still work in progress).

    Finally, libsigrok also contains the individual input/output file format drivers. Currently supported are: sigrok session (the default format, which contains all metadata), bits, hex, ASCII, binary, gnuplot, the OpenBench Logic Sniffer format, the ChronoVu LA8 format, Value Change Dump (VCD) viewable in gtkwave, and Comma-separated values (CSV).
    sigrok VCD file in gtkwave

  • libsigrokdecode, a shared library written in C, which contains the protocol decoder infrastructure and the protocol decoders themselves, which are written in Python (>= 3.0).

    The list of currently supported protocol decoders includes:

      dcf77                DCF77 time protocol
      lpc                  Low-Pin-Count
      mx25lxx05d           Macronix MX25Lxx05D
      jtag_stm32           Joint Test Action Group / ST STM32
      i2s                  Integrated Interchip Sound
      spi                  Serial Peripheral Interface
      edid                 Extended display identification data
      pan1321              Panasonic PAN1321
      mlx90614             Melexis MLX90614
      jtag                 Joint Test Action Group
      rtc8564              Epson RTC-8564 JE/NB
      transitioncounter    Pin transition counter
      usb                  Universal Serial Bus
      i2cdemux             I2C demultiplexer
      i2c                  Inter-Integrated Circuit
      i2cfilter            I2C filter
      mxc6225xu            MEMSIC MXC6225XU
      uart                 Universal Asynchronous Receiver/Transmitter

    Many more decoders are on our TODO list, and we especially welcome contributed protocol decoders, of course! We intentionally chose Python as implementation language for the decoders, to make them as easy to write (and understand) as possible, even if that means that performance suffers a bit. Have a look at the SPI decoder for example, to get a feeling for the implementation.

    Protocol decoders can be stacked on top of each other, e.g. you can run the i2c decoder and pipe its output into the rtc8564 (Epson RTC-8564 JE/NB) decoder for further processing of the RTC-specific, higher-level protocol. We also plan to support more complex stacking and combining of decoders in various ways in the nearer future.

  • sigrok-cli, is a command-line frontend, which uses both libsigrok and libsigrokdecode. It can acquire samples from logic analyzers and output them in various formats into files or to stdout, and/or run protocol decoders on the aquired data.

    Example: Data acquisition with 1MHz samplerate into a file.

     $ sigrok-cli -d chronovu-la8:samplerate=1mhz --time 1ms -o

    Example: Protocol decoding (JTAG).

     $ sigrok-cli -i -a jtag:tdi=5:tms=2:tck=3:tdo=7
     jtag: "New state: EXIT1-IR"
     jtag: "IR TDI: 11111110, 8 bits"
     jtag: "IR TDO: 11110001, 8 bits"
     jtag: "New state: UPDATE-IR"
     jtag: "New state: RUN-TEST/IDLE"

  • sigrok-qt, a Qt-based GUI for sigrok, using both libsigrok and libsigrokdecode.

    This is intended to be a cross-platform GUI (runs fine and looks "native" on Linux, Windows, Mac OS X) supporting data acquisition and protocol decoding.

    NOTE: The Qt GUI is not yet usable! We're working on getting it out of alpha-stage for the next release.

  • sigrok-gtk, a GTK+-based GUI for sigrok, using both libsigrok and libsigrokdecode (soon).
    This is a cross-platform GUI contributed by Gareth McMullin (thanks!), supporting data aqcuisition (and soon protocol decoding).

    NOTE: The GTK+ GUI is not yet fully usable (but it's more usable than sigrok-qt)! Consider it alpha-stage software for now.

We're happy to hear about other (maybe special-purpose) frontends you may want to write using libsigrok/libsigrokdecode as helper libs!


Saleae Logic

Some logic analyzer devices require firmware to be uploaded before they can be used. As always, firmware is a bit of a pain, but here's what we currently do: For non-free firmware we provide instructions how to extract it from the vendor software or from USB dumps, if possible. For distributable firmware we have a git repo where you can get it (thanks ASIX for allowing us to distribute the ASIX Sigma/Sigma2 firmware files!).

  $ git clone git://

Finally, for all Cypress FX2 based logic analyzers we have an open-source (GNU GPL) firmware named fx2lafw, started by myself, but most work (and finishing the firmware) was then done by Joel Holdsworth, thanks! The support list includes Saleae Logic, CWAV USBee SX, CWAV USBee AX, Robomotic Minilogic/BugLogic3, Braintechnology USB-LPS, and many others. Get the code from the fw2lafw git repository:

  $ git clone git://

Example dumps

We collect various captured logic analyzer signals / protocol dumps in the sigrok-dumps git repository:

  $ git clone git://

They can be useful for testing the sigrok command-line application, the sigrok GUIs, or the protocol decoders.

We're happy to include further contributed example data in our repository, please send us .sr files of any interesting data/protocol you may come across (even if sigrok doesn't yet have a protocol decoder for that protocol). See the Example dumps wiki page for details.

Packages, distros, installers

sigrok Windows installer

I'm currently working on updated Debian packages for sigrok (will be apt-get install sigrok to get everything), and we're happy about further packaging efforts for other distros. We have preliminary Windows installer files (using NSIS), but the Windows code needs some more fixes and portability improvements before it's really usable. On Mac OS X you can use fink/Macports to install as usual, fancier .app installer files are being worked on.


Apart from support for more logic analyzers, input/output formats, and protocol decoders, we have a number of other plans for the next few releases. This includes support for analog data, i.e. support for (USB) oscilloscopes, multimeters, spectrum analyzers, and such stuff. This will also require additional GUI support (which could take a while). Also, we want to improve/fix the Windows support, and test/port sigrok to other architectures we come across. Performance improvements for the protocol decoding as well as more features there are also planned.


Feel free to contact us on the sigrok-devel mailing list, or in the IRC channel #sigrok on Freenode. There's also an group for sigrok. We're always happy about feedback, bug reports, suggestions for improving sigrok, and patches of course!

Flashrom 0.9.4 released - Flashing BIOS/ROM chips from the Unix/Linux command line using various programmers

flashrom logo

Forgot to mention this here: We released flashrom 0.9.4 a few days ago, the latest release of the open-source, GPL'd ROM chip flashing software for Linux, *BSD, DOS, and partially also Windows (work in progress, though).

Here's a quick summary of the release announcement. Some of the noteworthy news items include:

  • Support for new programmers: OpenMoko Neo1973/Neo FreeRunner debug board version 2 or 3, Olimex ARM-USB-TINY, ARM-USB-TINY-H, ARM-USB-OCD, and ARM-USB-OCD-H, Open Graphics Project development card (OGD1), Angelbird Wings PCIe SSD/88SX7042, ITE IT85xx embedded controllers, Intel NICs with parallel flash.
  • Dozens of added flash chips, chipsets, mainboards.
  • Improved Dediprog SF100 support.
  • Add support for more than one Super I/O or EC per machine.
  • Always read the flash chip before writing, for improved error checking and faster programming.
  • Enable write support on NVIDIA MCP6x/MCP7x.
  • Lots of bugfixes, documentation fixes, internal improvements, etc.

Get the latest release tarball, or download and build the most recent version via Subversion:

  $ svn co svn:// flashrom
  $ cd flashrom
  $ make

I already updated the Debian package to 0.9.4 (it has also already migrated to Debian testing and Ubuntu), other people have updated Fedora, Gentoo, NetBSD etc. etc.

There's already a huge amount of patches queued for the next release, including support for even more programmers, PowerPC support (tested on Mac Mini and others), and of course the usual "more boards, more chips" items...

openbiosprog-spi, a DIY Open Hardware and Free Software USB-based SPI BIOS chip flasher using flashrom

openbiosprog-spi device

If you're following me on you probably already know that I've been designing a small PCB for a USB-based SPI chip programmer named openbiosprog-spi.

The main use-case of the device is to help you recover easily from a failed BIOS upgrade (either due to using an incorrect BIOS image, due to power outages during the flashing progress, or whatever). The device only supports SPI chips, as used in recent mainboards (in DIP-8 form factor, or via manual wiring possibly also soldered-in SO-8 variants). It can identify, read, erase, or write the chips.

Of course the whole "toolchain" of software tools I used for creating the hardware is open-source, and the hardware itself (schematics and PCB layouts) are freely released under a Creative Commons license (i.e., it's an "Open Hardware" device). The user-space source code is part of flashrom (GPL, version 2), the schematics and PCB layouts are licensed under the CC-BY-SA 3.0 license and were created using the open-source Kicad EDA suite (GPL, version 2).

openbiosprog-spi schematics
openbiosprog-spi Kicad PCB layout

The schematics, PCB layouts, and other material is available from gitorious:

  $ git clone git://

You can also download the final Gerber files (ZIP) for viewing them, or sending them to a PCB manufacturer.

Some more design notes:

  • The device uses the FTDI FT2232H chip as basis for USB as well as for handling the actual SPI protocol in hardware (MPSSE engine of the FT2232H).
  • Attaching the SPI chip:
    • There's a DIP-8 socket on the device so you can easily insert the SPI chip you want to read/erase/program.
    • Optionally, if you don't want a DIP-8 socket, you can solder in a pin-header with 8 pins, which allows you to connect the individual pins to the SPI chip via jumper wires or grippers/probes.
  • The PCB board dimensions are 44mm x 20mm, and it's a 2-layer board using mostly 0603 SMD components.

Basic usage example of the device on Linux (or other OSes supported by flashrom):

  $ flashrom -p ft2232_spi:type=2232H,port=A -r backup.bin (reads the current chip contents into a file)

openbiosprog-spi PCBs
openbiosprog-spi parts list

Over at the main projects page of openbiosprog-spi at

I have put up a lot more photos and information such as the bill of materials, the Kicad settings I used for creating the PCBs, the Gerber files and the Excellon drill files and so on.

The first few prototype boards I ordered at PCB-POOL.COM (but you can use any other PCB manufacturer of course), the bill of materials (BOM) lists the Mouser and CSD electronics part numbers and prices, but you can also buy the stuff elsewhere, of course (Digikey, Farnell, whatever).

I already hand-soldered one or two prototypes and tested the device. Both hardware and software worked fine basically, you just need a small one-liner patch to fix an issue in flashrom, but that should be merged upstream soonish.

In order to make it easy for interested users to get the PCBs I'll probably make them available in the BatchPCB Market Place soonish, so you can easily order them from there (you do still need to solder the components though). Note: I'm not making any money off of this, this is a pure hobby project.

All in all I have to say that this was a really fun little project, and a useful one too. This was my first hardware project using Kicad (I used gEDA/PCB, also an open-source EDA toolsuite, for another small project) and I must say it worked very nicely. I didn't even have to read any manual really, it was all pretty intuitive. Please consider not using Eagle (or other closed-source PCB software) for your next Open Hardware project, there are at least two viable open-source options (Kicad, gEDA/PCB) which both work just fine.

Using the HP Pavilion dv7-3127eg laptop with Debian GNU/Linux

HP Pavilion dv7-3127eg

Yep, so I bought a new laptop recently, my IBM/Lenovo Thinkpad T40p was slowly getting really unbearably sloooow (Celeron 1.5 GHz, 2 GB RAM max). After comparing some models I set out to buy a certain laptop in a local store, which they didn't have in stock, so I spontaneously got another model, the HP Pavilion dv7-3127eg (HP product number VY554EA).

Why this one? Well, the killer feature for me was that it has two SATA disks, hence allows me to run a RAID-1 in my laptop. This allows me to sleep better at night, knowing that the next dying disk will not necessarily lead to data loss (yes, I do still perform regular backups, of course).

Other pros: Much faster than the old notebook, this one is an AMD Turion II Dual-Core Mobile M520 at 2.3 GHz per core, it has 4 GB RAM (8 GB max), and uses an AMD RS780 / SB700 chipset which is supported by the Free-Software / Open-Source BIOS / firmware project coreboot, so this might make the laptop a good coreboot-target on the long run. I'll probably start working on that when I'm willing to open / dissect it or when the warranty expires, whichever happens first.

Anyway, I set up a page at which contains lots more details about using Linux on this laptop:

Most of the hardware is supported out of the box, though I haven't yet tested everything. There may be issues with suspend-to-disk / suspend-to-RAM, sometimes it seems to hang (may be just a simple config change is needed in /etc/hibernate/disk.cfg).

Cons: Pretty big and heavy (but that's OK, I use it mostly as "semi-mobile desktop replacement"), glossy screen, loud fans (probably due to the two disks).

For reference, here's an lspci of the box:

  $ lspci -tvnn
  -[0000:00]-+-00.0  Advanced Micro Devices [AMD] RS780 Host Bridge Alternate [1022:9601]
           +-02.0-[01]--+-00.0  ATI Technologies Inc M96 [Mobility Radeon HD 4650] [1002:9480]
           |            \-00.1  ATI Technologies Inc RV710/730 [1002:aa38]
           +-05.0-[08]----00.0  Atheros Communications Inc. AR9285 Wireless Network Adapter (PCI-Express) [168c:002b]
           +-06.0-[09]----00.0  Realtek Semiconductor Co., Ltd. RTL8111/8168B PCI Express Gigabit Ethernet controller [10ec:8168]
           +-11.0  ATI Technologies Inc SB700/SB800 SATA Controller [AHCI mode] [1002:4391]
           +-12.0  ATI Technologies Inc SB700/SB800 USB OHCI0 Controller [1002:4397]
           +-12.1  ATI Technologies Inc SB700 USB OHCI1 Controller [1002:4398]
           +-12.2  ATI Technologies Inc SB700/SB800 USB EHCI Controller [1002:4396]
           +-13.0  ATI Technologies Inc SB700/SB800 USB OHCI0 Controller [1002:4397]
           +-13.1  ATI Technologies Inc SB700 USB OHCI1 Controller [1002:4398]
           +-13.2  ATI Technologies Inc SB700/SB800 USB EHCI Controller [1002:4396]
           +-14.0  ATI Technologies Inc SBx00 SMBus Controller [1002:4385]
           +-14.2  ATI Technologies Inc SBx00 Azalia (Intel HDA) [1002:4383]
           +-14.3  ATI Technologies Inc SB700/SB800 LPC host controller [1002:439d]
           +-18.0  Advanced Micro Devices [AMD] K10 [Opteron, Athlon64, Sempron] HyperTransport Configuration [1022:1200]
           +-18.1  Advanced Micro Devices [AMD] K10 [Opteron, Athlon64, Sempron] Address Map [1022:1201]
           +-18.2  Advanced Micro Devices [AMD] K10 [Opteron, Athlon64, Sempron] DRAM Controller [1022:1202]
           +-18.3  Advanced Micro Devices [AMD] K10 [Opteron, Athlon64, Sempron] Miscellaneous Control [1022:1203]
           \-18.4  Advanced Micro Devices [AMD] K10 [Opteron, Athlon64, Sempron] Link Control [1022:1204]

Full lspci -vvvxxxxnnn, lsusb -vvv, and a much more detailed list of tested hardware components is available in the wiki.

Using the Oasis UMO19 MCU003 400x USB microscope on Linux via luvcview

Oasis UMO19 MCU003 digital USB microscope

I've been buying quite a lot of (usually cheapo) gadgets recently, which I'll probably introduce / review in various blog posts sooner or later. Let me start with a fun little gadget, a digital USB-based microscope. I found out about it via this thread over at

You can get this (or a very similar device) e.g. on eBay for roughly 50 Euros. Mine seems to be from a company called Oasis (though they're probably just the reseller, not sure). The device doesn't seem to have a nice name, but I can see UMO19 MCU003 on the microscope, so I guess that's the name or model number.

It can focus on magnifications of 20x or 400x. The image resolution is said to be a max. of 1600x1200, but in practice most of my images are 640x480, maybe I have to change some settings and/or the resolution depends on the magnification factor and lighting conditions.

The device acts as a simple UVC webcam when attached to USB, so you can view the images easily via any compatible webcam software, e.g. luvcview and also save screenshots of the magnified areas (see images).

UMO19 chip
UMO19 fabric

First three from left to right: SMD LED (400x), clothes/jacket (400x), random PCB (20x). The other two below: A via on a PCB (400x), and the "pixels" of a TFT screen (400x).

It worked out of the box on Linux for me, the uvcvideo kernel driver was loaded automatically.

 $ lsusb
 Bus 001 Device 013: ID 0ac8:3610 Z-Star Microelectronics Corp.

I set up a wiki page for more details (including full lsusb -vvv) and sample images at:

I will also post some more images there over the next few days.

UMO19 via
This is a really fun device for having a look at stuff you'd normally not see (or not well enough), and also useful for e.g. checking PCB solder joints, checking all kinds of electronics for errors or missing/misaligned parts, finding the chip name / model number of very tiny chips etc. etc. I can also imagine it's quite nice for biological use-cases, e.g. for studying insects, tissue, plants, and so on.

Anyway, definately a nice toy for relatively low price, I can highly recommend a device like this. Check eBay (search for e.g. "usb mikroskop 400") and various online shops for similar devices, there seem to be a large number of them with different names and from different vendors. Just make sure it has at least 400x magnification, there are also some with only 80x or 200x which is not as useful as 400x, of course.

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