2.9. FAQ

Note

Not found what you are looking for? Please contact us. Please include all the relevant information regarding the problem. For easier debugging on OS versions 2.00 and above, please also include the Downloaded system report in the bottom left corner of your Red Pitaya main webpage.

2.9.1. General troubleshooting

Here is a comprehensive guide to troubleshooting common problems with Red Pitaya. If you are experiencing problems with your Red Pitaya, please refer to the following sections:

• Connectivity.

• OS.

• Applications & Web Interface.

• Software.

• Hardware.

• How to report a problem?.

2.9.2. Troubleshooting proceedure

If you are experiencing problems with the Red Pitaya, please follow the steps below to troubleshoot the problem. If you are unable to solve the problem, please contact us.

Red Pitaya Status LED Description:

• Green LED - Power good.

• Blue LED - FPGA image loaded and OS booted.

• Red LED - CPU heartbeat.

• Orange LED - SD card access.

Check the status LEDs

Firstly, you should check the status LEDs as they will give you feedback on the type of error you are experiencing.

1. If the green LED is OFF or blinking. There appears to be something wrong with the power supply or USB cable. Make sure that:

   • You have plugged the USB cable into the correct USB port on the Red Pitaya.

   • Your power supply is capable of delivering 5V/2A (or 12V/1A for SIGNALlab 250-12).

   • Try replacing the USB cable and the USB power supply.

   If none of the above helps, please contact us.

2. If the green LED is turned ON but the blue LED is turned OFF and the orange LED is barely lit. In this case, there is an error loading the Red Pitaya file system from the SD card. Make sure that:

   • You have connected the USB cable to the correct USB port on the Red Pitaya.

   • You have inserted the Red Pitaya SD card correctly and the Red Pitaya OS is installed (Note that Red Pitayas come with a pre-installed OS on SD cards. However, SD cards can become corrupted - in this case follow these instructions to Prepare SD card to properly reinstall the Red Pitaya OS on the SD card).

   • If you have recently upgraded your OS and Red Pitaya was working and now it is not, this is probably due to an incorrect hw_rev number in the EEPROM. Please see this GitHub issue #250. The RMA terms in the GitHub issue will be offered to anyone with this issue, regardless of warranty.

   • Try a different SD card.

   • Try connecting via a serial console and check the boot sequence for feedback:

     1. Red Pitaya should print information about the boot sequence.

     2. Check that the Zynq SoC is booting (message Autoboot will start in 3…2…1… (Hit any key to stop)).

     3. Check that the kernel boot sequence shows no signs of looping.

     4. If the kernel boot reaches the Linux welcome message, then the Red Pitaya is fine. Check that the blue LED is not damaged.

     If the serial console gives no feedback during the boot sequence, please contact us.

   • If you have Pavel Demin’s Alpine Linux OS image installed, this may indicate normal behaviour. The status LEDs are normally off, see the Pavel Demin's Red Pitaya Notes for more information.

3. If both the Green and Blue LEDs are ON, but the Red and Orange LEDs stop flashing a few seconds after booting, only to remain ON for about 2 seconds, and then the cycle repeats. This indicates that the Red Pitaya is in a reboot cycle. Note that the red and orange LEDs will always start flashing approximately 10 seconds after the green and blue LEDs are turned ON.

   • Check your Red Pitaya board model. If you are using an external clock version, check that the external clock signal is correctly connected to the E2 connector. Make sure that the clock specifications match the recommended ones:

     • STEMlab 125-14 External Clock.

     • SDRlab 122-16 External Clock.

Check the network connection

If the status LEDs are working normally, the Red Pitaya is booting correctly. If you are unable to connect, this is most likely a network problem:

1. Make sure your Red Pitaya and computer are both connected to the same local network.

2. Consult the connection guide for advice.

3. Try using the recommended up-to-date Google Chrome browser.

4. Disable any adblockers for the rp-xxxxxx.local website.

5. Try disabling the VPN as it may be preventing the connection.

6. Type arp -a in a command prompt or terminal and look for Red Pitaya’s IP. Then try using the IP instead of rp-xxxxxx.local in the URL window of the browser.

7. Check that DHCP is enabled on your router.

8. If you are a Windows user, please see the note below.

   Note

   Windows 7/8 users should install Bonjour Print Services, otherwise access to *.local addresses will not work.

   Windows 10 or higher already supports mDNS and DNS-SD, so there is no need to install any additional software.

9. Try connecting to the board from a different computer and router. Some networks may have security restrictions that prevent you from connecting (for example, university networks require all devices to connect through a special web page to confirm a person’s identity).

Advanced Troubleshooting

1. If you are a Linux or MacOS user and the Red Pitaya is connected directly to the computer (via the Ethernet cable), check the Ethernet port settings to see if they are set to DHCP and Local Only. Alternatively, try connecting to the Red Pitaya through your router.

2. If a MAC computer will not connect to the Red Pitaya, it is possible that Content and privacy settings are blocking websockets. After updating the settings you will need to log out and log in again.

   

   

   It may be necessary to completely disable content and privacy settings.

   

3. If you have updated from 1.04 (or older) to 2.00 OS version, check GitHub issues #250 and #254.

4. For STEMlab 125-14 Gen 1 board models, check if the UART TX pin on the E2 connector is driven high (3V3) before or during the boot sequence, this can prevent you from logging into the unit.

5. Try connecting via serial console. Check the boot log and see if you can access the built-in Linux terminal.

6. Check the nightly builds changelog for any relevant updates.

7. Check the known hardware issues for Gen 1 and :Gen 2 boards and known software issues in the software section.

Extremely rare cases

1. If the board works normally but the blue LED is OFF, check that the LED is not damaged. If the board is under warranty, we will replace it.

2. Check that one of the pins of the SD card holder is bent upwards and not in contact with the pins of the SD card. Remove the SD card and push it into the normal position.

2.9.3. Connectivity

How to get started with Red Pitaya?

• Quick start.

How to connect to Red Pitaya in a few simple steps?

• Connected to router.

• Direct connection to computer.

Red Pitaya not booting anymore?

• A possible cause could be a corrupted card, and the recommendation is a manual OS re-write: Prepare SD card.

• Please check troubleshooting guide for status LED description.

• Was the OS updated recently?.

Red Pitaya is constantly rebooting?

• A board reset during boot-up is indicated by the green and blue LEDs lighting up, followed by the orange and red LEDs pausing their blinking to remain ON for about 2 seconds, then the cycle repeats. Repeated board resets suggest an external clock signal is missing (not connected) on the external clock board variations. Check the external clock specifications and instructions for your Red Pitaya board model:

  • Gen 2 STEMlab 125-14.

  • Gen 1 STEMlab 125-14 External clock.

  • SDRlab 122-16 External clock.

How to connect the external clock to RP?

• Gen 2 STEMlab 125-14.

• Gen 1 STEMlab 125-14 & STEMlab 125-14-Z7020 External clock.

• SDRlab 122-16 External clock.

How can I make sure that my Red Pitaya has access to the internet?

1. Connect to your Red Pitaya over SSH.

2. Make sure that you can ping google.com website:

   root@rp-f03dee:~# ping -c 4 google.com
   PING google.com (216.58.212.142) 56(84) bytes of data.
   64 bytes from ams15s21-in-f142.1e100.net (216.58.212.142): icmp_seq=1 ttl=57 time=27.3 ms
   64 bytes from ams15s21-in-f142.1e100.net (216.58.212.142): icmp_seq=2 ttl=57 time=27.1 ms
   64 bytes from ams15s21-in-f142.1e100.net (216.58.212.142): icmp_seq=3 ttl=57 time=27.1 ms
   64 bytes from ams15s21-in-f142.1e100.net (216.58.212.142): icmp_seq=4 ttl=57 time=27.1 ms
   
   --- google.com ping statistics ---
   4 packets transmitted, 4 received, 0% packet loss, time 3004ms
   rtt min/avg/max/mdev = 27.140/27.212/27.329/0.136 ms
   

How can I make sure that Red Pitaya is connected to the same network as my computer/tablet/smartphone?

The most common answer would be: just make sure that your Red Pitaya and your PC/tablet/smartphone are both connected to the same router or your smartphone hotspot.

In order to test it, you can use a PC that is connected to the same local network as your Red Pitaya and try the following:

1. Open the terminal window.

   • Windows: Go to RUN, type in cmd and press enter.

   • Linux: Click on the application button, type in the Terminal and press enter.

   • macOS: Hit cmd + space, type in the Terminal and press enter.

2. Enter the arp -a command to get a list of all devices in your local area network and try to find your Red Pitaya MAC address on the list.

   $ arp -a
   ? (192.168.178.117) at 00:08:aa:bb:cc:dd [ether] on eth0
   ? (192.168.178.118) at 00:26:32:f0:3d:ee [ether] on eth0
   ? (192.168.178.105) at e8:01:23:45:67:8a [ether] on eth0
   

   Note

   If you have a cable connection, then your MAC address is written on your Red Pitaya LAN connector.

   

   Note

   If you have established a wireless connection, then you should check the MAC address of your wireless USB dongle. The MAC addresses are typically written on the USB dongles.

3. Type your Red Pitaya IP into your WEB browser and connect to it.

   

If your Red Pitaya is not listed on the list of your local network devices on the local network, then it is necessary to check that your Red Pitaya is connected to your local network.

Is Red Pitaya connected to my local network?

1. Connect your Red Pitaya to a PC over a Serial Console.

2. Type ip a and hit enter to check the status of your ethernet connection on Red Pitaya.

   1. If you have connected to your Red Pitaya over a wireless connection, you should check the status of the wlan0 interface.

   2. If you have connected to your Red Pitaya over a cable connection, you should check the eth0 interface.

3. Type Red Pitaya IP into your web browser to see if you can connect to it.

   

How to find the Red Pitaya URL if it is not written on the sticker?

The Red Pitaya URL is rp-xxxxxx.local where xxxxxx must be replaced with the last 6 digits of the MAC address that is written on the sticker.

If the RP MAC address is 00:26:33:F1:13:D5, the last 6 digits are F113D5 and the URL is rp-f113d5.local.

Slow Wi-Fi connection?

If your wireless connection with Red Pitaya works very slowly and all the applications seem very unresponsive and not running smoothly, please check the following:

1. Check the Wi-Fi signal strength on your PC/tablet/smartphone.

2. Check the Wi-Fi signal strength of your Red Pitaya.

   1. Connect to your Red Pitaya via an SSH connection.

   2. Enter the cat /proc/net/wireless command to get information about link quality and signal strength.

      

      Link quality measures the number of packet errors that occur. The lower the number of packet errors, the higher this will be. Link quality goes from 0-100%. Level, or signal strength, is a simple measure of the amplitude of the signal that is received. The closer you are to the access point, the higher this will be.

3. If you are in an area with many routers around you, more of them might operate on the same Wi-Fi channel, which drastically decreases data throughput and slows down connection. Here are the instructions on how to change your wifi router channel in order to optimize your wireless signal. For MAC users, we recommend using the Scan feature of the Wireless Diagnostic Tool in order to find the best Wi-Fi channel.

Note

For full performance, a wired connection is preferred.

Wi-Fi dongle not detected?

Please note that not all are compatible. A list is in the documentation: Supported USB Wi-Fi adapters.

2.9.4. OS

How to update & upgrade OS?

• OS update options.

Is Red Pitaya not booting even after OS update?

• Please use the Balena Etcher application to rewrite the OS manually.

• Upgraded from an older Red Pitaya OS to the 2.00 Unified OS? Please try #250 and #254.

Is Red Pitaya failing to update?

There are two possible solutions to this problem:

• If the Software update tool reports that your Red Pitaya is offline, please connect the Red Pitaya into an ethernet socket with internet access. Internet connection is not shared with the directly connected devices without some setting configurations.

• Please use the Balena Etcher application to manually rewrite the Red Pitaya OS on the SD card.

2.9.5. Applications & Web Interface

How can I start using RP measurement applications?

• Connect to Red Pitaya.

My device shows the wrong measurements. How can I calibrate it?

The Red Pitaya can be calibrated using the Calibration Tool.

I am not getting any signal on the inputs or outputs of my Red Pitaya?

If you are not getting any signal on the inputs or outputs of your Red Pitaya, please check the following:

1. Check the input jumpers. Sometimes the jumpers have poor contact and need to be removed and replaced. If the jumpers are loose or missing, please replace them.

2. Check the calibration settings in the web interface. A bad calibration can cause Red Pitaya to display incorrect measurements or even appear to detect no signal at all. This applies to both the inputs and outputs of the Red Pitaya. Both the DC and frequency calibration settings should be checked and reset to factory defaults if necessary.

Problems with OS update application, and accessing the marketplace?

1. Make sure your Red Pitaya has access to the internet.

2. Force a refresh of the Red Pitaya application page. Here is a link to the Wiki How page.

3. The OS update application can take a long time to update the OS on Red Pitaya. The quickest way to update the OS is to manually rewrite the OS on the SD card.

Web interface not functioning properly, or freezing?

Please ensure that your browser’s ad blockers are turned off for the rp-xxxxxx.local webpage and that your proxy settings are correct. For local connections to the Red Pitaya unit, proxy settings should not be required. A VPN may also be preventing the connection.

Here are a few things you can try:

• Update the Google Chrome browser.

• Disable ad blocker’s for the rp-xxxxxx.local website.

• Disable VPN.

• Clear cookies for the rp-xxxxxx.local website.

• Try incognito mode.

• Update the Red Pitaya OS to the latest version.

Undesired disconnections?

We recommend connecting the Red Pitaya to a router (or an ethernet port that is connected to it) and testing the setup again. If the problem persists, please test the setup on a different computer and a different network. Also check the state of the Ethernet cables and power supply, proxy settings, and re-writing the OS.

An application is not working?

We suggest upgrading to the latest OS and trying again. Otherwise, please report a problem.

Note

It is important to note that applications developed by the Red Pitaya community are not distributed or tested by the Red Pitaya team and that our team accepts no responsibility. If you’d like to share feedback, report bugs, or need help on contributed projects, apps, or software, we highly recommend contacting the project authors.

Note

With the 2.00 Unified OS, we also updated Ubuntu to 22.04 LTS, which introduced registry changes implemented by AMD Xilinx in the way the FPGA bitstream image is loaded into the FPGA. As a result, we had to update all official applications to work with the new structure. Unfortunately, not all 3rd party applications have been updated, so they may not work with the latest OS versions. In this case, we recommend either downgrading the Red Pitaya OS version to 1.04 or using an alternative application.

Lock-in PID applications not working?

Depending on the Red Pitaya OS version you are currently using, some of the Lock-In PID applications may not work. Here is a compatibility table:

Lock-in PID application	Application type	Compatible Red Pitaya OS	Red Pitaya board compatibility	Link to documentation
Linien	3rd party	2.00-15 and above 1.04 (Limited compatibility)	STEMlab 125-14 (LN, Ext. clk)	Linien GitHub
Lock-in+PID (Marcelo Luda)	3rd party	1.04-28 or older	STEMlab 125-14 (LN, Ext. clk) STEMlab 125-10 (discontinued)	Lock-in+PID GitHub
PyRPL	3rd party	2.00 or higher (check our docs) 1.04-28 or older (from PyRPL docs)	STEMlab 125-14 (LN, Ext. clk) STEMlab 125-10 (discontinued)	PyRPL documentation

Note

Using other board models is possible, but requires a change in the FPGA to account for a different FPGA (Zynq 7020 instead of Zynq 7010).

The PyRPL executables for 2.00 are available here.

Note

With the 2.00 Unified OS, we also updated Ubuntu to 22.04 LTS, which introduced registry changes implemented by AMD Xilinx in the way the FPGA bitstream image is loaded into the FPGA. As a result, we had to update all official applications to work with the new structure. Unfortunately, not all 3rd party applications have been updated, so they may not work with the latest OS versions. In this case, we recommend either downgrading the Red Pitaya OS version to 1.04 or using an alternative application.

2.9.6. Software

For establishing an SSH connection, creating a custom FPGA image, custom ecosystem, and/or custom web applications, please refer to Developers guide Software.

How can I acquire data with Red Pitaya?

• Introduction to data acquisition and generation with Red Pitaya.

How can I generate data with Red Pitaya?

• Introduction to data acquisition and generation with Red Pitaya.

How to control Red Pitaya remotely using LabVIEW, MATLAB, and Python?

• Remote control.

Where can I find the ecosystem, software, and FPGA images?

• Red Pitaya ecosystem - please check the specific branches for older ecosystem versions.

• Red Pitaya FPGA.

• Red Pitaya archive - software archive (some images may require separate ecosystem and Linux OS installation). Check the nightly build installation instructions.

Note

Impossible. Perhaps the archives are incomplete.

If you need a specific old version of the ecosystem or the OS that is missing from the archives, we suggest you ask the community on the Red Pitaya Forum. There is a chance someone has it lying around on the disk.

How to start with FPGA development?

• Software.

• FPGA tutorials.

Are there any restrictions on installing Python packages?

No, there are no restrictions on installing Python packages. Any package that can be installed on Ubuntu Linux can be installed on Red Pitaya. If you are facing issues with the installation, they are most likely caused by one of the following reasons:

• Not enough space on the SD card. Ensure there is enough space on the SD card as some packages may require a lot of space.

• Not enough memory. If the package installation requires a lot of memory, it may not be possible to install it on Red Pitaya (512 MB RAM).

Enabling swap does not help with this issues.

Building packages from source tarball may help circumvent these issues.

2.9.7. Hardware

For hardware schematics, step models, and specifications, please refer to Developers guide Hardware.

Where can I find Red Pitaya schematics, 3D models (.step), and important componetns?

Please take a look at Developers guide Hardware => board model => Schematics, Mechanical Specifications and 3D Models. See the general link above, or board-specific links below.

• STEMllab 125-14 Gen 2.

• STEMlab 125-14 Gen 1.

• SDRlab 122-16.

• SIGNALlab 250-12.

• STEMlab 125-10.

Is there a hardware difference between the STEMlab125-14 and the ISO17025 versions?

No, the hardware is identical. The only difference is that the latter would have been sent to a certification lab and the appropriate measurements would have been made.

Is there a hardware difference between between normal boards and OEM versions?

No, the hardware is identical. The OEM board comes without the additional accessories (power supply, SD card, etc.) that are present in the starter kit.

What is the difference between STEMlab 125-14 and STEMlab 125-14 Low Noise?

STEMlab 125-14 Low Noise has additional linear power regulators that reduce the noise on the fast analog outputs. This is the only difference between the two boards. You can find more information in the STEMlab 125-14 Low Noise documentation.

Is the STEMlab 125-14 board in the “Calibrated kit” calibrated?

Yes, the STEMlab 125-14 board in the “Calibrated kit” is factory calibrated. Please keep in mind that all Red Pitaya boards regardless of the kit are calibrated in the factory. Recalibration, if necessary, can be performed by the user via the Calibration Tool. If you are looking for a board with a calibration certificate, please check the ISO17025 version of the STEMlab 125-14 board.

What are the main differences between different Red Pitaya boards?

Take a look at the board comparison tables:

• Gen 1 board comparison table.

• Gen 2 board comparison table.

What is the bandwidth of the Red Pitaya boards?

All Red Pitaya boards operate in the base band (DC to approximately 60 MHz). The SDRlab 122-16 (core clock frequency 122.88 MHz) has AC coupling that limits the lower frequency to 300 kHz and has an ADC that can downsample signals from 550 MHz into the base band. To reach higher frequency ranges, additional analog fronted modules are required (for example, frequency mixers).

2.9.8. How to report a problem?

Please email us at support@redpitaya.com with the following information

• The model of Red Pitaya you are using.

• The version of Red Pitaya OS.

• Information about the problem you are experiencing and any additional information that may be relevant.

• Any visual material showing the status LEDs or the state of the board is welcome.

• Clear instructions on how to reproduce the problem.