Low-Cost Logic Analyzers

Logic analyzer is a very useful tool for embedded system debugging.

In many embedded-system magazines and on Web sites you’ll see advertisements for instrument “boxes” or pods that connect to a PC through a USB port. These devices capture digital and analogue signals that a host PC displays in a standard scope or logic-analyzer format. Several logic analyzer devices come with software that can decode I2C, SPI, and other serial protocols, and provide timing information. There are also devices can create analog and digital signals, too.

Are Low-Cost Logic Analyzers Up to the Challenge? mentions that those cheap logic analyzers are made by companies such as USBee, Byte Paradigm, PoScope, CleverScope, Intronix, Saleae, Saelig, TechTools, and BitScope. I would add to the list interesting looking product like Bus Pirate, Ikalogic Scanalogic-2, Pickit2, ArduinoLab Arduino shield and Digilent Analog Discovery.

Some specifications for this class of instruments prove difficult to determine and thus compare. So, you must understand the types of signals you plan to capture and analyze, the logic levels you’ll work with, and sample rates. Here are some comments from me on several logic analyzer products.

Microchip PICkit 2 Logic Tool allows the PICkit 2 ICSP connector pins to be used for stimulating and probing digital signals in a target circuit, and as a simple 3 channel logic analyzer with up to 1 MHz sample rate. PICkit 2 Development Programmer/Debugger works as a simple logic analyzer when you make yourself your own problems (easy just some soldering).

Saleae has a USB logic probe hardware and Logic Software for it. Logic Software download gives you ability to download this software to test how it works (provides some demo signals to test without hardware). The software that can decode quite many different kind of signals (I2C, SPI, asynchronous serial, etc..). You can read more on the devices on my blog posting Saleae Logic Analyzer. This is a very popular product and there are Chinese made clones of this.

slogic

USBee makes a quite good selection of logic analyzer pods with and without analogue inputs. Their software USBee Suite software seem to be quite good at quick test. his is a very popular product and there are Chinese made clones of this.

Bitscope products are are USB or Ethernet connected PC Based Mixed Signal Oscilloscopes. You can Test Drive BitScope DSO, free of charge. The software downloaded to PC will connect to a remote BS300N that the manufacturer have put on the Internet. Like the original BitScope published in Circuit Cellar magazine in 1999, the hardware design of BitScope 300 is open and published online and full schematics are available for download. Interesting product family that I have not had hands on experience with.

Analog Discovery is a two channel scope (100 MSPS), waveform generator (100MSPS), logic analyzer. It is part of Analog circuit design kit jointly by ADI and Digilent. This is an interesting looking product. It is all-in-one analog design kits that will enable engineering students to quickly and easily experiment with advanced technologies and build and test real-world, functional analog design circuits. In addition to this there are logic analyzer functionality. This looks an interesting product.

19 Comments

  1. Tomi says:

    I found Scanalogic-2 Logic Analyzer software to have quite good signal generating functions. And in addition to this the software has option to export the generated signal in several formats (including CSV).

    http://www.ikalogic.com/ikalogic-products/scanalogic-2/

    Reply
  2. Tomi Engdahl says:

    PICkit 2 Logic Analyzer
    http://pk2-la.sourceforge.net/

    This is the PICkit 2 Logic Analyzer project (“pk2-la”)

    The Microchip PICkit 2 has the ability to act as a logic analyzer and I/O probe. This project provides a reverse engineered libusb user space device driver and GUI to provide this functionality for users of unsupported operating systems.

    Reply
  3. Tomi Engdahl says:

    SIGMA2 – Logic Analyzer
    http://tools.asix.net/dbg_sigma.htm

    SIGMA2 – Logic Analyzer

    SIGMA2 is a powerful, fast, flexible, user-friendly and cost effective logic analyzer with extraordinary large event memory, real-time hardware compression and complex trigger logic. SIGMA2 operates on a USB port and requires no external power supply.

    Features

    Extremely large event memory (256 megabit = over 14 millions samples)
    Real-time hardware data compression
    Up to 200 MHz sample speed
    Up to 16 inputs Windows and Linux
    Flexible trigger options
    “Logic probe” mode
    Controlled and powered by USB (Full-Speed, 12 Mbps)
    Advanced software (for Windows and Linux)

    Reply
  4. Philip Terrible says:

    Excllent pieces. Maintain psting such sort of suggestions on you page.m eally imressd by yur internet.

    Reply
  5. Tomi Engdahl says:

    A FPGA based Bus Pirate Clone
    http://hackaday.com/2014/03/10/a-fpga-based-bus-pirate-clone/

    A necessary tool for embedded development is a device that can talk common protocols such as UART, SPI, and I2C. The XC6BP is an open source device that can work with a variety of protocols.

    As the name suggests, the XC6BP is a clone of the Bus Pirate, but based on a Xilinx Spartan-6 FPGA. The AltOR32 soft CPU is loaded on the FPGA.

    A simple USB stack runs on the soft CPU, creating a virtual COM port.

    Reply
  6. Tomi Engdahl says:

    Test system for embedded designs in compact USB box
    http://edn.com/electronics-products/other/4435056/Test-system-for-embedded-designs-in-compact-USB-box?_mc=NL_EDN_EDT_EDN_productsandtools_20140929&cid=NL_EDN_EDT_EDN_productsandtools_20140929&elq=1372d21da20449e29769a8c1841b878e&elqCampaignId=19362

    Pico Technology’s PicoScope 300D Mixed Signal Oscilloscope is a tool for engineers working with a diverse range of embedded systems. Implemented as a compact USB-connected box, the 3000D forms a complete portable test system with two or four analog and as many as 16 digital channels. A built-in arbitrary waveform generator rounds off the feature set.

    Available with analog bandwidths from 60 MHz to 200 MHz, the 300D’s maximum digital input frequency is 100 MHz which is equivalent to a data rate of 200 Mb/s (5 ns pulse width) on each channel. All models come with a high-bandwidth USB 3.0 interface, giving high performance and fast update rates as well as portability to USB 2.0 ports.

    Like all PicoScopes, they display waveforms in a resizable window on the user PC’s screen.

    A free SDK is available for developing applications in popular programming languages such as C, Microsoft Visual Basic and Excel VBA, and National Instruments LabVIEW, with example code included.

    Reply
  7. Tomi Engdahl says:

    Bus Blaster v4
    http://store.hackaday.com/products/bus-blaster-v4

    Bus Blaster v4 is an experimental, high-speed JTAG debugger from Dangerous Prototypes. Thanks to a reprogrammable buffer, a simple update over USB makes Bus Blaster compatible with many different JTAG debugger types in the most popular open source software.

    Compatible with ‘jtagkey’, ‘KT-link’ programmer settings in OpenOCD, urJTAG, and more.
    Ships with JTAGkey compatible buffer image pre-programmed.

    Reply
  8. Tomi Engdahl says:

    Open Workbench Logic Sniffer
    http://store.hackaday.com/products/open-workbench-logic-sniffer

    Capture 50MHz+ waveforms on 32 channels.
    16 buffered channels, 5 volt tolerant.
    M74LCX16245DTR2G transceiver tolerates voltages from -0.5V to +7V.
    216K Block RAM.
    External clock and trigger input; allows interfacing with external test equipment and daisy chaining OLS’s for additional channels.
    Internal clock and trigger output.
    16bit wing expansion header.
    USB interface, USB powered.
    USB upgradable everything.
    Designed for the SUMP logic analyzer client.
    Open source.
    Low price.

    The hardware is designed for the SUMP open source logic analyzer client and toolchain. This project is a joint venture between Gadget Factory and Dangerous Prototypes.

    Reply
  9. Tomi Engdahl says:

    The Bus Pirate is a universal electronic open hardware tool to program and interface with communication buses and program various chips, such as AVRs from Atmel and PICs from Microchip Technology. A primary usage case for this device as intended by the designers is to “Eliminate a ton of early prototyping effort with new or unknown chips.”[1] Using a Bus Pirate, developers can use a serial terminal to interface with devices over a variety of hardware protocols, such as SPI and 1-Wire.
    http://en.wikipedia.org/wiki/Bus_Pirate

    Bus Pirate
    http://dangerousprototypes.com/docs/Bus_Pirate

    The Bus Pirate is an open source hacker multi-tool that talks to electronic stuff. It’s got a bunch of features an intrepid hacker might need to prototype their next project. This manual is an effort to link all available Bus Pirate information in one place.

    Reply
  10. Tomi Engdahl says:

    Logic Pirate
    http://store.hackaday.com/products/logic-pirate

    The Logic Pirate is an inexpensive, yet capable open source logic analyzer. It is designed to support the SUMP logic analyzer protocol.

    8 channels.
    256,000 Samples recording size.
    20 MHz sampling speed; can potentially be overclocked to 60 MHz.

    Reply
  11. Tomi Engdahl says:

    DSLogic
    http://store.hackaday.com/products/dslogic

    Logic Analyzer with max 400 MHz sample rate, 256 Mbits on-board memory, and max 16 channels.
    $109.97

    Reply
  12. Tomi Engdahl says:

    The BitScope Raspberry Pi Oscilloscope
    http://www.bitscope.com/pi/

    Connect any BitScope via USB or Ethernet with Raspberry Pi to build a complete stand-alone mixed signal oscilloscope, logic analyzer, spectrum analyzer and waveform generator.

    Reply
  13. Tomi Engdahl says:

    BitScope Micro
    http://www.raspberrypi.org/bitscope-micro/

    This is the BitScope Micro, built especially for the Raspberry Pi. It turns your Pi into a dual channel digital oscilloscope, a multi-channel logic analyser, a waveform and clock generator and a spectrum analyser; it comes bundled with BitScope’s full suite of software (well worth a look if you’re even slightly interested – this thing has features coming out of the wazoo), and it’s probably the cheapest digital scope we’ve ever seen, coming in at USD $95 if you buy in volume, and $145 at one-off retail. You can read much more at BitScope’s website.

    BitScope Micro Oscilloscope & Analyzer
    http://bitscope.com/product/BS05/

    Just like BS10 this is a fully featured mixed signal test & measurement system, a mixed signal scope in a probe!

    20 MHz Bandwidth.
    40 MSps Logic Capture.
    2 Analog Scope Channels.
    2 Analog Comparator channels.
    6 Logic/Protocol Analyzer channels.
    8 & 12 bit native analog sample resolution.
    Decodes Serial, SPI, I2C, CAN and more.
    Windows, Linux, Mac OS X & Raspberry Pi.
    Built-in analog waveform & clock generators.
    User programmable, C/C++, Python, VM API.
    Tiny, light weight (14g) and water resistant.
    Standard oscilloscope probe adapters available.

    Reply
  14. Tomi Engdahl says:

    Review: DSLogic Logic Analyzer
    http://hackaday.com/2015/05/26/review-dslogic-logic-analyzer/

    Logic analyzers historically have been the heavy artillery in an engineer’s arsenal. For many of us, the name invokes mental images of large HP and Tektronix iron with real CRT screens. Logic connections were made through pods, with hundreds of leads weaving their way back to the test equipment. The logic analyzer came out when all else failed, when even a four channel scope wasn’t enough to figure out your problems.

    There have been a number of USB based logic analyzers introduced in recent years, but they didn’t really catch on until Saleae released their “Logic” line of devices. Low cost, high-speed, and easy to use – these devices were perfect.

    There have been a number of USB based logic analyzers introduced in recent years, but they didn’t really catch on until Saleae released their “Logic” line of devices. Low cost, high-speed, and easy to use – these devices were perfect.

    Reply
  15. Tomi Engdahl says:

    Hack Mobile with a Bus Pirate GUI for Your Phone
    http://hackaday.com/2016/01/30/hack-mobile-with-a-bus-pirate-interface-for-your-phone/

    You need to get an SPI bus on something right now, but you left your laptop at home. No problems, because you’ve got your Bus Pirate and cellphone in your pocket. And a USB OTG cable, because you’re going to need one of those. And some probes. And maybe a soldering iron for tacking magnet wire onto those really small traces. And maybe a good magnifying glass. And…

    OK, our fantasy of stepping away from the party for a quick JTAG debugging session is absurd, but what’s not at all absurd is the idea of driving your Bus Pirate from a nice GUI app on your Android phone. [James Newton] wrote DroidScriptBusPirate so that he wouldn’t have to hassle with the Bus Pirate’s nested single-character menu system, and could easily save complete scripts to do common jobs from pleasant menus on his phone.

    DroidScript GUI for BusPirate
    Have a complete, although very basic, electronics bench in your pocket on the cheap.
    https://hackaday.io/project/8863-droidscript-gui-for-buspirate

    DroidScriptBusPirate is a User Inferface for the BusPirate^ (pocket electronics bench tool) which runs in the DroidScript app on Android phones. It simplifies talking to the BP (BusPirate) via USB OTG by providing a list of commands and setup wizards for the commands which require parameters. As a result, you don’t have to remember the cryptic command codes.

    BusPirate is a little open source device that connects a USB host device (PC, MAC, or cellphone / tablet via USB OTG) to electronic stuff. It can speak with several different busses (I2C, SPI, UART, etc…) and devices (LCDs, servos, AVRs, FPGAs, CPLDs, etc…) and can inject signals, or measure voltages. It’s a little test bench in your pocket for less than $30.

    Reply
  16. Tomi Engdahl says:

    Bus Pirate Commandeers I2C
    http://hackaday.com/2017/02/07/bus-pirate-commandeers-i2c/

    The Bus Pirate is one of our favorite tool for quick-and-dirty debugging in the microcontroller world. Essentially it makes it easy to communicate with a wide variety of different chips via a serial terminal regardless of the type of bus that the microcontroller uses. Although it was intended as a time-saving prototyping device, there are a lot of real-world applications where a Bus Pirate can be employed full-time, as [Scott] shows us with his Bus Pirate data logger.

    Logging I2C Data with Bus Pirate and Python
    http://www.swharden.com/wp/2017-02-04-logging-i2c-data-with-bus-pirate-and-python/

    Here I show how to pull data from this I2C device directly via a serial terminal, then show my way of automating the process with Python.

    The Bus Pirate website even has a page showing how to read data from LM75, but it uses a pyBusPirateLite python package which has to be manually installed (it doesn’t seem to be listed in pypi).

    I found a cool pypy-indexed python module pyElectronics which should allow easy reading/writing from I2C devices via BusPirate and Raspberry Pi. However, it crashed immediately on my windows system due to attempting to load Linux-only python modules.

    Therefore, I’m keeping it simple and using a self-contained script to interact with the Bus Pirate, make temperature reads, and graph the data over time.

    Reply
  17. Tomi Engdahl says:

    Everything You Need To Know About Logic Probes
    http://hackaday.com/2017/07/29/everything-you-need-to-know-about-logic-probes/

    comprehensive treasure trove of information regarding a subject that we should all know more about — sniffing logic signals. Sure, it’s a long video, but [Joel] of [OpenTechLab] leaves no stone unturned.

    At the center of the video is the open-source sigrok logic capture and analyzer. It’s great because it supports a wide variety of dirt cheap hardware platforms, including the Salae logic and its clones. Logic is where it shines, but it’ll even log data from certain scopes, multimeters, power supplies, and more. Not only can sigrok decode raw voltages into bits, but it can interpret the bits as well using protocol decoder plugins written in Python. What this all means is that someday, it will decode everything. For free.

    [Joel] knows a thing or two about sigrok because he started the incredibly slick PulseView GUI project for it, but that doesn’t stop him from walking you through the command-line interface, which is really useful for automated data capture and analysis, if that’s your sort of thing. Both are worth knowing.

    In our opinion sigrok, and the el cheapo hardware logic probes that it supports deserve a place in every hacker’s toolbox. This video is the best introduction to the software, and the topic in general, that we’ve ever seen.

    [001] Sigrok and Logic Analyzers
    https://www.youtube.com/watch?v=dobU-b0_L1I

    Reply
  18. Tomi Engdahl says:

    DSLogic Plus Teardown and Review
    http://hackaday.com/2017/08/24/dslogic-plus-teardown-and-review/

    The DSLogic open source logic analyzer is on its second release (the plus version) and [OpenTechLab] has a comprehensive review of the new model, which, unlike the original model, includes a different method of connecting probes and provides a separate ground for each input pin.

    The device is pretty simple inside with an FPGA, a RAM, and a USB microcontroller. There’s also a configuration EEPROM and a switching power supply. The device stores up to 256 megabits internally and can sample 400 million samples per second on 4 of its 16 channels. [OpenTechLab] even puts the board under a microscope and maps out the input circuit.

    Unlike a lot of USB logic analyzers, the new arrangement of probes and dedicated ground allows the probes to use a very short flying lead that connects to a thin piece of coax.

    [009] DSLogic Logic Analyzer Review and Teardown
    https://www.youtube.com/watch?v=xZ5wKYnCNcs&t=2s

    Review, teardown and experiments with the DSLogic Plus 400Msps 16-channel logic analyzer.

    Reply
  19. tomi says:

    I use WordPress.

    Reply

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