This Readme supports setting up your RFSoC4x2, where the RFSoC4x2 is connected directly to the internet--Wide Area Network (WAN).
The RFSoC4x2, as shown in the image below, is a board built and sold by Real Digital using AMD’s ZYNQ Ultrascale+ Gen 3 RFSoC ZU48DR chip. While the ZU48DR has eight digital-to-analog converters (DACs) and analog-to-digital converters (ADCs), the RFSOC4x2 only uses four DACs (5 GSa/s) and two ADCs (9.85 GSa/s). Nonetheless, this number of inputs and outputs is nearly perfect for NV and quantum defect control. However, as the RFSOC4x2 is sold, the ADCs have a high frequency 1GHz high-pass balun inline which is typically too high frequency for our measurements and thus must be modified.
In this document we outline the setup for using QICK-DAWG with a RFSoC4x2. Specifically, we show how to:
-
Install QICK-DAWG and other software to your RFSoC4x2
a. Flash your microSD card
b. Clone QICK-DAWG on your RFSoC4x2
c. Install necessary packages on your RFSOC4x2
d. Run the Pyro server to remotely connect to QICK and the RFSoC4x2 -
Setup lab control computer
a. Download/clone QICK-DAWG
b. Install necessary packages -
Setup RFSoC4x2 Hardware
a. Photon counting mode
b. Low frequency analog modification
c. Connect PMOD digital outputs
d. Assemble and power on your RFSoC4x2
e. (Optional) Full enclosure
- RFSoC4x2 (with 12 volt 50 watt power supply)
- Ethernet cord
- Micro SD card reader (DC Mode)
- Low frequency differential amplifier Texas Instruments LMH5401EVM
- 3 x DC output voltage supply (+3.2, +0.7, -1.8V for biasing the differential amplifier)
- SMA cables
- Win32DiskImager for Windows or Disk Manager on MacOS
- Dependent packages (follow
Installing Necessary Packagessection--included in the setup batch file)
(Getting started directions adapted from QICK ZCU111 quick-start-guide)
- First, you will need to flash the micro SD card with the RFSoC4x2 PYNQ v3.0.1 image found here. Download the RFSoC4x2 PYNQ image and unzip the file if it is a .zip file.
(Windows)
- With your micro SD card plugged in to your computer, open Win32DiskImager. Select the PYNQ file as your image file and select your micro SD card as the device. Double check you are not flashing the image file to the wrong drive (not your computer hard drive)! To execute, click
Write.
Once the image is written to the microSD card, put the microSD card into the RFSoC4x2, connect to the internet via ethernet, and turn the board on. The LED screen on top of the board will have your ip address which you will need for further steps.
SSH directly into the board via windows cmd.exe with the command
ssh xilinx@{ip address}
Where the ip address is the value shown on the LED screen on top of the board. You will then be prompted for the password, which is also xilinx and asked to store the ssh footprint, for which you should respond yes.
Now you'll have remote, terminal control of the board. From here type
cd ./jupyter_notebooks
git clone https://github.com/sandialabs/qick-dawg
This will download the qick-dawg repository to the default directory of the jupyter notebook server run by the RFSoC4x2.
With the required files copied to your RFSoC4x2, we will now install the required packages by running an .ipynb though the RFSoC4x2's Jupyter Notebook server. To connect to the jupyter notebook server:
In a browser window type your RFSoC4x2 IP address as shown on the board's LED screen and use password xilinx as shown in the graphic below
From the home page, navigate to the installation folder, open install_packages.ipynb and run all of the cells to install the packages. This doesl three things:
- installs pyro4 for remote control of the board
- downloads and installs qick
- moves some files around
With all of the packages installed, you can now run your Pyro server to connect to an instance of QICK. This is accomplished by running two jupyter notebooks.
- First we run
run_server/name_server.ipynbwhich starts a Pyro server. In this notebook, you need to change the IP address to the IP address of your board.
- Second, we run the
run_server/qick_daemon.ipynbnotebook, which uploads firmware to the RFSoC4x2 and creates a python socket to communicate with the board. This notebook has a string which contains the path to our alternative firmware and has ans_hostvariable which needs to be assigned to the IP address of your RFSoC4x2 board.
With these two notebooks running you can now start communicating with your RFSoC4x2 from a python kernel on your main computer. From here, we recommend running through qickdawg/jupyter_notebooks/NVDemo_RFSoC4x2.ipynb which contains significant documentation on how to run our basic NV characterization notebooks.
Note that the qick_daemon notebook specifically points to a firmware made for qick-dawg.
You need a local copy of QICK-DAWG on your lab control computer. There are two options for obtaining a local copy of QICK-DAWG
- use a git manager to clone QICK-DAWG, found at
https://github.com/sandialabs/qick-dawg(on windows VSCode is nice for this) - download QICK-DAWG as a .zip file from the GitHub repository and unzip it.
To run your RFSoC4x2 from your lab computer you need to install QICK-DAWG. To install QICK-DAWG, on your lab computer:
- In the command prompt navigate to
*\qick-dawg - Enter
pip install -e ./
This will install QICK-DAWG and it's dependent packages.
With the remote pyro4 server running on the RFSoC4x2 and qick-dawg installed on your local computer you should now be able to connect to the demo notebooks in the /qick-dawg/jupyter_notebooks folder.
The ADC inputs on the RFSoC4x2 have baluns inline which act like long pass filters. When we first made QICK-DAWG we had to bypass these for photodiode readout. However, for single photon countings from a single photon detector module, the TTLs generate by each photon arrival can pass through the balun with sufficent signal to be counted. Thus a single photon detector can be directly plugged into an ADC for counting mode as demo'd in coutning_demo_RFSoC4x2.ipynb.
To setup for this demo, plug your microwave amplifier into DAC_B and your single photon detector into ADC_D. Additionally, connect your laser gate into PMOD 0 (section 3c).
The ADCs on the RFSoC must be modified because ~1MHz signal measured by the photodiodes cannot be directly connected to the ADCs on the board. The ADCs on the RFSoC4x2 have baluns and capacitors that act as high pass filters. When using photodiodes for photoluminesence detection, the signal is low frequency, therefore unmodified ADCs do not let the signal from the photodiodes pass. Given this, the balun must be removed and the capacitors bypassed to readout the signal from the photodiodes with the ADCs. Furthermore, as the ADCs take in a differential voltage signal, we have to add a differential amplifier which takes the signal from the photodetector in and outputs a biased signal to the ADCs for digitization (see section 1.b below).
The input electronics for one ADC channel on the RFSoC4x2 is shown in the figure below.
The combination of the balun (MABA-801111) and the two 100nF capacitors (C302 and C303) result in a high pass filter. In order to collect the signal, we need to remove the balun and bypass the capacitors. Our clumsy method is to pull off the balun (under an RF shield) and solder input wires on the down current side of the capacitors.
To properly condition our signal for digitization, we use a Texas Instruments Texas Instruments LMH5401 EVM evaluation board. This board takes in one or two signals and outputs two voltages above (Vp) and below (Vm) a common voltage (Vcm). For full scale, the RFSoC4x2 requires an offset voltage of Vcm = 0.7V (note that this is also true for the ZCU216 evaluation board, but the ZCU111 evaluation board requires Vcm = 1.2 V). Additionally, the differential amplifier requires two voltages for power, which are optimally set to (Vcm + 2.5) = 3.2V and (Vcm - 2.5 )= -1.8. A labeled diagram of the LMH5401EVN is shown in the figure below.
To connect the low frequency differential amplifier to the RFSoC4x2,
- solder a 3.3 V input wire to the red V+ post on the low frequency differential amplifier;
- solder a -1.8 V input wire to the yellow V- post on the low frequency differential amplifier;
- screw a 0.7 V SMA wire to the Vcm (V common) SMA head on the top of the low frequency differential amplifier;
- cut a semi-flexible SMA cable in half and strip the insulation off of both ends to expose the center conductor ;
- screw the SMA heads of the cut SMA cable to Vp and Vm SMA heads on the low frequency differential amplifier--screwing on the SMA cables now will limit the torsion on our delicate soldering in the next steps;
- take the SMA cables attached to the low frequency differential amplifier and solder them to the RFSoC4x2.
- Vp should be soldered to the far side of the top capacitor
- Vm should be soldered to the far side of the bottom capacitor
The image below is an image of the diff amp wired to the capacitors and the balun removed for a working RFSoC4x2 with DC inputs.
RFSoC4x2 Schematic 1
Note if you are worried about removing the balun from your RFSoC4x2, marketplaces such as Digikey sell replacement baluns which can be used to restore the functionality of modified ADCs in the future.
To control the laser with TTLs you must connect your laser to the PMOD located on the corner of the board. To connect, we cut the female head off a PMOD cable and soldered on a female BNC head instead. PMOD A 0-7 are enabled for QICK-DAWG (in the demo we use PMOD 0). The image below provides a schematic of the PMOD on the RFSoC4x2.
With the hardware modified and differential amplifier connected, the RFSoC4x2 can be assembled to be connected to your computer. This connection is made with a WAN connection and a router. To do so:
- slide your micro SD card into its slot on the RFSoC4x2 board and check that the BOOT switch is on SD mode;
- connect an Ethernet cable from the board to the router;
- and connect the RFSoC4x2 to its power supply and turn it on.
You should hear the fan above the RFSoC chip begin to whir and you should see green LED lights blinking all over the board. After about 30 seconds the boot light should turn green and the LED screen will display the board's IP address. Your setup should resemble the schematic below.
In our lab, we have assembled all the necessary components into a custom rack box (Bud Industries CH-14404 Enclosure) with screw holes and 3D printed cages for fastening components. Hardware setup instructions for the enclosure can be found on our QICK-DAWG Read the Docs site. The following CAD files for the enclosure are found in qickdawg/installation/enclosure:
- Enclosure_Front.SLDPRT, CAD for custom enclosure front panel holes for SMA and BNC pass through
- Enclosure_Main.SLDPRT, CAD for custom enclosure drill holes to secure components
- Low_Freq_Diff_Amp_Base.SLDRT, CAD for 3D printable differential amplifier support for mounting the differential amplifier near the RFSoC 4x2 board
- Low-Freq_Diff_Amp_Top.SLDPRT, CAD for 3D printable differential amplifier top
- Router_Holder.SLDPRT, CAD for 3D printable router cage for holding the router in the enclosure
While this is listed as optional, for DC mode it is really required to sabilize the differential ampifier relative to the RFSoC4x2.