This documentation is for a development version. Click here for the latest stable release (v0.2.2).

Getting Started

Things You Need

Installation Quick Reference Guide

First, get the your board NengoFPGA ready using the device-specific board setup documentation. Once your board is set up, do the following steps on the PC connected to the board:

  1. Install NengoFPGA.

  2. Edit the NengoFPGA config file to match your setup.

  3. Test NengoFPGA by running the ID extractor script:

    1. In a terminal on your computer navigate to the root nengo-fpga directory.

    2. Run the ID extractor script with:

      python nengo_fpga/ <board>

      where <board> is the board name as it appears in fpga_config. See the Copy Protection section for more information.

  4. Now with the Device ID available, you are ready to acquire your bitstreams.

  5. Once the bitstreams and supporting files have been delivered, copy these files to the appropriate location as outlined in the device-specific bitstream documentation.

  6. Test NengoFPGA by running an example script:

    1. Navigate to nengo-fpga/docs/examples.

    2. Run the basic example script:

      python <board>

      where <board> is the board name as it appears in fpga_config.

    3. If the script has a successful run you will see a lot of [INFO] printed to the console indicating the status of the NengoFPGA system. Near the bottom you will see the RMSE of the network printed:

      Computed RMSE: 0.00105

      You may get a slightly different value but if your NengoFPGA system is functioning correctly, this should be near 0.001.


    If you run the script and it hangs waiting for the simulation to begin but does not display any errors, then it is likely a firewall issue. Ensure your firewall allows connections to and from the board IP address.

NengoFPGA Software Installation

Download the NengoFPGA source code from github using git:

git clone

or navigate to the repository and download the files manually. Once downloaded, navigate to the nengo-fpga folder in a terminal window and install with:

pip install -e .

FPGA Board Setup

Follow documentation for your particular FPGA device:

The full list of hardware that NengoFPGA supports, and the links to their respective documentation can be found here.

NengoFPGA Software Configuration

NengoFPGA is the frontend that connects to one of many backend FPGA devices. You will need to have a supported FPGA board with access to Applied Brain Research’s designs. Each FPGA board will have it’s own setup and configuration procedure outlined in it’s own documentation, however, the NengoFPGA frontend has its own configuration as outlined below.

The NengoFPGA default config file, fpga_config, is located in the root directory of nengo-fpga and contains example settings for your host machine as well as the FPGA board you are using. You can also create a copy in the directory in which your project files are located. Anything in square brackets (eg. [host]) defines a new entry name and everything below that name up until the name defines parameters of that entry.


First we will look at the host configuration; this is information about your computer and must be called [host]:

ip =

Make sure these lines are uncommented (remove the leading # and space so it appears as above). This is just an example value for ip, you will need to replace this with your computer’s actual IP address, see Finding your IP Address for instructions on finding your IP address.


Your computer IP address will need to be in the same subnet as the board IP address, follow your board specific instructions to get the board IP and setup your computer IP before proceeding.

FPGA Board

The entries that define the FPGA board parameters have more values than the host entry, the name (eg. [pynq]) can be anything, though we recommend using a descriptive name such as [pynq] or [de1].


Every board connected to the same network must have its own entry in the config file.

# Example DE1 FPGA board configuration
ip =
ssh_port = 22
ssh_user = root
ssh_pwd =
# Refer to the online documentation for SSH key configuration options
remote_script = /opt/nengo-de1/nengo_de1/
id_script = /opt/nengo-de1/nengo_de1/
remote_tmp = /opt/nengo-de1/params
udp_port = 0

# Example PYNQ FPGA board configuration
ip =
ssh_port = 22
ssh_user = xilinx
ssh_pwd = xilinx
# Refer to the online documentation for SSH key configuration options
remote_script = /opt/nengo-pynq/nengo_pynq/
id_script = /opt/nengo-pynq/nengo_pynq/
remote_tmp = /opt/nengo-pynq/params
udp_port = 0

For whichever board you are using, make sure the lines in the appropriate sections are uncommented (remove the leading # and space so it appears as above). These default values should be correct unless you’ve modified the settings or installation of your FPGA board. These parameters are described here but modifications of these values will be described in the board-specific documentation.

  • ip: IP address of the FPGA board.

  • ssh_port: The port used to open SSH communications between the host and FPGA board.

  • ssh_user: SSH username to use to login to the board.

  • ssh_pwd: Password for ssh_user to use to login to the board. Note that the fpga_config file supports the use of SSH keys (see Generating and Using SSH keys) as an alternate form of authentication.

  • remote_script: The location of the main communication script on the FPGA board.

  • id_script: The location of the script that extracts the unique device identifier.

  • remote_tmp: Temporary location used to store data as it is transferred between the host and FPGA board.

  • udp_port: The port used for UDP communications between the host and FPGA board.


It should be noted that the FPGA board should be configured such that non-root users do not require a password to perform sudo commands. If you are using the NengoBrainBoard SD image on your board, this should already be done. If not, refer to the respective FGPA board documentation for instructions on how to do this.

Copy Protection

Our hardware design (known as the bitstream) is locked to a specific device. Each bitstream is compiled with your unique board identifier (called Device ID) and therefore you will need to provide this unique ID to us before we can compile and deliver your tailored bitstream.

Reading Device ID

To easily read your Device ID, first ensure you have setup your board to be NengoFPGA ready. Instructions on how to do this can be found in each board’s respective documentation (see Board Setup). Additionally, ensure you have reviewed the NengoFPGA configuration section, and appropriately modified the fpga_config file.

Once done, simply run the script located in the nengo_fpga directory from within the nengo-fpga root folder. This will print the Device ID as well as save it to a file for future reference. The script requires that you provide the name of your board as it appears in the fpga_config file (eg. pynq, de1). From the root directory (nengo-fpga) run:

python nengo_fpga/ <board>

After running this script you will see some information printed to the console indicating the status of the NengoFPGA system. Upon successful execution of the script the final lines should read:

Found board ID: 0X0123456789ABCDEF
Written to file id_<board>.txt

Now that you have your Device ID, you are ready to acquire your bitstreams.


Compiled FPGA designs are binary files that configure the hardware, literally strings of bits, so compiled designs are often called bitstreams. When getting started or updating you NengoFPGA system, you will need to get bitstreams for your device. The NengoFPGA bitstreams are tailored to your specific device.

A NengoFPGA license (available from the Applied Brain Research store) is required to obtain a NengoFPGA bitstream. After purchasing the appropriate device-specific license, follow the instructions below to obtain your tailored bitstream.

Acquiring NengoFPGA Bitstreams

If you haven’t already, you will need to get your Device ID.

To receive your tailored bitstreams, please send us an email at with the following information:

  • The email address tied to your NengoFPGA license. Typically this is the email address provided at the store checkout.

  • Your Device ID. Either the hex string itself or attach the id_<board>.txt file to the email.

  • Which supported hardware device is associated with that Device ID.

  • To help our support team provide a prompt response, please start your subject header with the term “NengoFPGA”.

Updating NengoFPGA Bitstreams

Once you have received your bitstreams, follow documentation for your particular FPGA device for how to copy them to the board and get them running: