PulseView User Manual

On Linux, the usual way to install PulseView is to install the packages provided by your distro’s package manager. However, sometimes only outdated packages are made available to you. In that case, you have two options:

We offer installers for PulseView that contain everything you need to get started. Simply download them from the sigrok download page and run them as any other Windows installer. Please be aware, however, that the Windows installers are built every night, so they always contain the latest development changes. While we do try to keep the code base in a working state, it is sometimes unavoidable to introduce bugs that show up in the nightly builds. If you encounter something that is odd to you, please download and install the latest nightly and check if the issue still exists. If it does, feel free to file a bug.

After installation, you will find a program called Zadig in the start menu. By default, certain devices recognized by Windows will have drivers installed for them that PulseView cannot use. The purpose of Zadig is to let you change the driver Windows uses for a particular device - for most devices you’ll need to choose WinUSB to use them with PulseView or the original proprietary Windows driver to use it with whatever other software you access the device with. More details are available in the wiki.

In case your device doesn’t show up in PulseView and you can’t find it with a scan either (see next chapter), check with Zadig whether the correct driver is assigned for the device.

We offer DMG installers for PulseView that contain everything you need to get started. Simply download them from the sigrok download page and run them.

Please be aware, however, that the DMG installers are built every night, so they always contain the latest development changes. While we do try to keep the code base in a working state, it is sometimes unavoidable to introduce bugs that show up in the nightly builds. If you encounter something that is odd to you, please download and install the latest nightly and check if the issue still exists. If it does, feel free to file a bug.

No system files are changed, so if you decide that you no longer want to use PulseView, simply delete the DMG file. If you also want the stored settings gone, delete ~/Library/Preferences/pulseview.plist as well.

The device selector offers two methods to choose the device to use. If you click on the small arrow on the side, you see a list of devices PulseView has recognized. If the device you want to use is listed, you can just select it here.

If it’s not listed, you’ll need to scan for it first. Since most serial port and Ethernet devices can’t be auto-detected, this is usually required for those. To do so, either choose the "Connect to Device" option from the list or click on the button itself. You will see the following dialog:

First, you’ll need to pick a driver that you want to use. In order to do this, you’ll need to know which driver is used to talk to the device. If you’re unsure, you can either try the driver which you think may fit best or you can check the wiki. For every supported device there’s a wiki page, showing you which driver is used.

Once the driver has been chosen, you need to select the interface. Please be aware that USB is only usable for devices that directly communicate over USB. Devices that use USB to emulate a serial port (like the OpenBench Logic Sniffer) will have their serial port listed in the serial port drop-down.

In case your device connects via Ethernet, you must supply the IP address and port. You are also given the option to choose between raw TCP access and using the VXI protocol. VXI is an industry standard which is mainly used in professional equipment and the device will most likely let you know that it supports VXI. If your device however is more of a hobbyist grade device, it’s more likely that using raw TCP will be the correct choice.

After you selected the appropriate options, clicking the scan button will make PulseView try to connect to the device with the given settings. If successful, any device(s) found will be shown in the list box.

You may then change the device configuration and/or start the data acquisition by clicking the "Run" button on the top left.

When you run the acquisition, you’ll notice that the newly captured data goes off-screen. This is to improve performance and let PulseView acquire the data without bogging down your CPU too much. If you find this inconvenient because you’d like to see what kind of data is coming in, you have three options:

Which method suits you best is up for you to decide.

In PulseView, the device configuration is done using these buttons:

The values offered for those four elements depend on your device. Which settings you should choose depends on several factors: the needs of your measurement, the device you use to capture the data and the capabilities of your computer.

The sample rate you choose must at least be twice that of the highest frequency you want to capture - ideally 3 to 5 times as much so that you have some margin. That way, a jittering signal won’t ruin your measurements.

The signal labels on the left side of the view (D0, D1 and so on in the picture above) allow you to configure certain aspects of these signals. If the device supports it then the trigger that will be used for this signal will be among them.

As of now, the trigger system is awaiting extension for advanced and complex trigger types, meaning that the only triggers available to you are:

Once you choose a trigger, the icon for the type you chose becomes visible on the right side of the trace view.

When you click "Run" with a trigger configured, PulseView will wait for the device to trigger and send data before it can show anything. There is currently no frame limit, so if the device driver supports it, PulseView will continue arming the trigger and collecting data until you either click "Stop" or it runs out of memory.

Some devices share certain settings between a group of channels, which is why PulseView may show the channels your device offers in groups. You can see which channels are grouped by looking at the dark gray bar on the left. If there is none, no channels are grouped.

Currently, the grouping is only done for your convenience and there’s no direct functional impact. This means that you’re free to ungroup and group channels as you please. To do so, right-click on the dark gray bar and select "Ungroup". If you want to create a new group, select the signals you want to group by holding down CTRL and clicking on the signal labels. Once you have selected the ones you want to be grouped, right-click on one of the labels you selected and choose "Group".

Just looking at the signal data however is usually not sufficient. A lot of times, you’ll want to make sure that timings are honored and the bit times are like what you’d expect. To do so, you’ll want to use cursors and markers.

In the picture above, you can enable the cursor by clicking on the cursor button. You can move both of its boundaries around by clicking on the blue flags in the time scale area. The area between the two boundary lines shows the time distance, its inverse (i.e. the frequency) and/or the number of samples encompassed. If there’s not enough space to see these, you can either zoom in until it shows, hover the mouse cursor over the label in the middle or right-click on the label to configure what you want to see. You can also move both boundaries at the same time by dragging said label.

Markers are movable indicators that you can create wherever you like on the time scale - just double-click on it and it’ll create one for you where your mouse cursor is at the time, or use the context menu when right-clicking on the ruler or a signal trace. You can click on its label and you’ll have the option to change its name, or drag it to reposition it.

When you have multiple markers, you can have PulseView show you the time difference between the markers by hovering over one of them, like so:

This works on the cursor, too.

Speaking of which - if you want to place or move the cursor ranges quickly, you can also press 1 and 2 on your keyboard to attach either side to your mouse cursor. They will stay put when you either press Esc or click with the left mouse button. This also works when the cursor isn’t even showing, so using this method allows you to place the cursor quickly without having to enable it first.

There are some decoders available that analyze the data instead of decoding it. You can make use of them to examine various properties of the signals that are of interest to you.

Among them are:

Another one of the protocol decoders available to you is the I²C decoder. It takes the two I²C signals SCL and SDA (serial clock / serial data) and shows you the details of the I²C communication without the need to evaluate the signal bit by bit yourself.

As an example, let’s have look at one of the sample .sr files we keep around for validation of the PD code base: rtc_ds1307_200khz.sr. It contains the capture of an I²C master interacting with a Dallas DS1307 I²C Real-Time Clock where the master repeatedly sets and queries the time of day. After loading and using "zoom-to-fit", it looks similar to this:

Adding the I²C decoder by clicking on ➊ and selecting I²C from the list adds a new decode signal to the view. PulseView tries to match existing signals to the signals that the newly added protocol decoder needs to function, which is what happened here - SCL and SDA have been automatically assigned and the PD has decoded the communication with the default parameters. If you need to change the signal assignment or change the decoding parameters, you can click on ➋ to do so.

When you zoom in, you now see that PulseView has decoded the I²C messages and displays these annotations as part of the decode signal (note that we have zoomed in so far that PulseView shows you the individual samples):

This is already very useful, and a massive improvement over counting out pulses on an oscilloscope screen. However, sigrok allows us to go one step further with the use of so-called stacked decoders.

To add a stacked decoder we open the settings of the decode signal, go to the Stack Decoder menu ➊, and select the DS1307 decoder:

With the stacked decoder added, we can now see that PulseView has decoded the meaning of the I²C commands, so that we don’t need to bother searching the reference manual. In this view, we can see that the I²C packet was a command to read the date and time, which was then reported to be "10.03.2013 23:35:30".

In this example, we added the I²C and DS1307 decoders separately. However, when opening the decoder selector window, you can also double-click on the DS1307 decoder and PulseView will try to auto-resolve the dependencies needed to use this decoder. In case there are ambiguities (e.g. when several different protocol decoders offer uart output), it will ask you to choose which one to use.

For a list of available and planned protocol decoders, you can check the wiki.

If you’re capturing data using an oscilloscope or import analog signal data from a file, you’ll quickly notice that protocol decoders don’t give you the option to select analog channels as inputs. That is because as of now, decoders only work on logic signals. You can however convert analog signals into logic signals by choosing a conversion setting from the signal setting popup.

Here, A1 has been converted using a threshold (with default settings) and A2 has been converted using a Schmitt-Trigger emulation (also with default settings). Additionally, the conversion threshold display mode has been set to Background in the Views settings dialog. This way, you can tell how PulseView decided to change the logic signal level as you can now visually understand where the ranges for high and low are placed.

Aside from the default conversion threshold(s), you can choose from a few common presets or enter custom values as well. They take the form "0.0V" and "0.0V/0.0V", respectively.

Sometimes, you don’t want to see all protocol decoder rows or all of the annotation classes available in a row. To do so, simply click on the arrow or label of the row you want to customize.

From that menu, you can either show/hide the entire row or choose the annotation classes you want to see. Everything is visible by default but if you want to focus on specific protocol messages or status annotations like warnings or errors, this should help.

Also, if you are examining really long traces, disabling annotations for the most-often occuring class (e.g. bit annotations for SPI) then drawing performance will increase, too.

While all protocol decoders create visible annotations, some of them also create binary output data which isn’t immediately visible at the moment. However, you can examine it by opening the Binary Decoder Output View as shown below.

Once opened, you need to select a decoder with binary output for it to show anything - among which are I2C, I2S, EEPROM24xx, SPI and UART. Having acquired some I2S data and using the I2S protocol decoder lets you have the sound data as raw .wav file data, for example:

Using the save icon at the top then lets you save this data either as a binary file (in this case creating a valid .wav file) or various types of hex dumps. If you want to only save a certain part of the binary data, simply select that part before saving.

You may have noticed that the bytes are grouped by color somehow. The meaning behind this is that every chunk of bytes emitted by the protocol decoder receives one color, the next chunk another color and so on. As there are currently three colors, the cycle repeats. This makes it easier to visually organize the data that you see - in the case of the I2S decoder, the header has one color because it’s sent out in one go and following that, every sample for left/right consists of 4 bytes with the same color since they’re sent out one by one.

In case a protocol decoder doesn’t provide the expected result, there are several things you can check.

The first check you should perform is whether the time unit in the ruler is given as "sa". This is short for "samples" and means that the device didn’t provide a sample rate and so PulseView has no way of showing a time scale in seconds or fractions thereof. While some decoders can run without timing information, or only optionally make use of it, others may not be able to interpret the input data since timing information may be an essential part of that protocol.

Another issue to remain aware of is that decoders need enough samples per protocol step to reliably interpret the information. In typical cases the minimum sample rate should be 4-5 times the rate of the fastest activity in the protocol (e.g. its clock signal).

If a protocol decoder runs but shows you annotations that don’t seem to make any sense, it’s worth double-checking the decoder settings. One common source of error is the baud rate. For example, the CAN protocol decoder doesn’t know what baud rate is used on the bus that you captured, so it could be that a different baud rate is used than the one you set. If this is still not the reason for the malfunction, it’s worth checking whether any of the signals have been captured inverted. Again using the CAN bus as an example, the decoder will decode the signal just fine if it’s inverted but it’ll show data even when the signal looks "idle".

When a protocol decoder stops execution because of an unmet constraint (required input not connected, essential parameter not specified) or a bug in the decoder itself, you will be presented a static red message in the protocol decoder’s display area. In that case, you can check the log output in the settings menu. There you’ll find the Python error description which you can use to either adjust the configuration, debug the decoder (and let us know of the fix) or create a bug report so that we can fix it.

Further helpful knowledge and explanations on logic analyzers can be found in our "Learn about logic analyzers" FAQ item.

If you want to postprocess annotations that were generated by a protocol decoder, you can do so by right-clicking into the area of the decode signal (not on the signal label on the left). You are shown several export methods to choose from, with the last one being only available if the cursor is enabled.

After you chose a method that suits your needs, you are prompted for a file to export the annotations to. The contents of the file very much depend on the option you chose but also on the annotation export format string that you can define in the Decoders menu of the settings dialog. If the default output isn’t useful to you, you can customize it there.

For example, the string "%s %d: %1" will generate this type of output for the DS1307 RTC clock protocol decoder: "253-471 DS1307: Read date/time: Sunday, 10.03.2013 23:35:30"

Protocol decoders are written in Python and can be created using nothing more than a text editor. You, too, can write one!

To find out how to go about it, please see our Protocol Decoder How-To and the Protocol Decoder API Reference.

If you do write one, we’d appreciate if you’d contribute to our project so that everyone can benefit from your work.

The first step to importing data from a file is to know what format the data in the file is encoded in. There are common, not-so-common and outright exotic ways to represent data and sigrok tries to suit as many needs as it can. To see which formats your version of PulseView supports, just click on the small arrow next to the Open button:

After choosing the format that you want to use, PulseView will ask for the file name to open. Once you picked the file, you may be asked to specify the details of the format, if the input module requires them.

For example, the VCD import will ask you for these:

The detailed description of each item can also be seen when clicking on the help icon on the right or hovering your mouse over it. A click on OK then loads the data from the selected file and you can work with it.

Export works just the same as the import: clicking on the small arrow next to the Save button brings up the export menu. Simply choose the format you want to use and proceed.