> For the complete documentation index, see [llms.txt](https://weenslab.gitbook.io/pages/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://weenslab.gitbook.io/pages/fpga-tutorials/fpga-boards-getting-started/getting-started-with-pynq-on-red-pitaya-stemlab-125-14.md).
# Getting Started with PYNQ on Red Pitaya STEMlab 125-14
## Red Pitaya STEMlab 125-14
Red Pitaya is a project that aims to provide an alternative to numerous expensive laboratory measuring and control instruments. It is classified as open-source, but the hardware design is proprietary. This board uses the **Xilinx Zynq 7000 (XC7Z010-1CLG400C)**.
This board has its own Linux image that comes with web-based measurement applications, but in this case I don't do measurement, so I want to try to use the PYNQ image.
## MicroSD Setup
Red Pitaya STEMlab 125-14 is not officially supported by PYNQ. Thankfully, someone has already built the PYNQ image for this board. So, I just use the PYNQ image from this [repository](https://github.com/dspsandbox/Pynq-Redpitaya-125).
#### Required programs:
* Win32DiskImager ()
* PuTTY ()
#### How to write the image to a microSD card:
1. Download the image file **Pynq-Redpitaya-125-14-3.0.1.img** from the repository.
2. Write the image file to the microSD card with the **Win32DiskImager** program.
#### How to boot the board:
1. Insert the microSD card into the board, connect the micro USB cable to the PC, and connect the power supply.
2. Open the **PuTTY** program and set up a serial connection. Select the appropriate COM port by looking at Device Manager (Windows).
* Baud rate = **115200**
* Data bits = **8**
* Stop bits = **1**
* Flow control = **None**
* Parity = **None**
3. The system is automatically logged in, but if you want to connect to the board from an SSH terminal, then we have to enter the username and password.
* Username: **xilinx**
* Password: **xilinx**
{% hint style="info" %}
**Important**
If you want to turn off the board, you should shutdown it; don't immediately remove the power supply. This is done to avoid corrupted microSD, which can cause boot failure.
{% endhint %}
#### How to turn off the board:
Run this command.
```sh
sudo shutdown -h now
```
## USB Wi-Fi Dongle Setup
I use an **Edimax EW-7811Un** USB Wi-Fi dongle that uses the **Realtek RTL8188CUS** chipset. The driver for this Wi-Fi dongle is already installed.
We can use this command to display information about USB buses and the devices connected to them. We will see the USB Wi-Fi dongle detected.
```sh
lsusb
```
Next, we can use this command to connect to a Wi-Fi access point.
```sh
sudo wpa_passphrase "YourSSID" "YourPassword" > wpa_supplicant.conf
sudo wpa_supplicant -c wpa_supplicant.conf -i wlan0 -B -Dnl80211
```
Then, use this command to configure a static IP address.
```sh
sudo nano /etc/network/interfaces.d/wlan0
```
```
allow-hotplug wlan0
iface wlan0 inet static
address 192.168.1.99
netmask 255.255.255.0
gateway 192.168.1.1
wpa-conf /etc/wpa_supplicant/wpa_supplicant.conf
```
Finally, we can reboot the board to see the changes.
```sh
sudo reboot
```
Now, we can login to the Jupyter Notebook via web browser by entering the IP address of the board:
* URL: **192.168.1.99:9090**
* Password: **xilinx**
## Wi-Fi Connection with PEAP
We can also connect to a Wi-Fi access point that uses PEAP, which is commonly used in enterprise wireless and wired networks. This is the configuration for the `wpa_supplicant.conf`.
```sh
sudo nano /etc/wpa_supplicant/wpa_supplicant.conf
```
```
network={
ssid="YourSSID"
scan_ssid=1
key_mgmt=WPA-EAP
identity="YourUsername"
password="YourPassword"
eap=PEAP
phase1="peaplabel=0"
phase2="auth=MSCHAPV2"
}
```
This configuration is used to configure the board with a dynamic IP address.
```sh
sudo nano /etc/network/interfaces.d/wlan0
```
```
allow-hotplug wlan0
iface wlan0 inet dhcp
wpa-conf /etc/wpa_supplicant/wpa_supplicant.conf
```
## DNS Configuration
For some reason, when I try to install a Python package using `pip`, an error occurs, and I find that the error is related to the DNS configuration. So, I set the DNS permanently in the `resolv.conf` file.
```
WARNING: Retrying (Retry(total=4, connect=None, read=None, redirect=None, status=None)) after connection broken by 'NewConnectionError(': Failed to establish a new connection: [Errno -3] Temporary failure in name resolution')': /simple/yfinance/
WARNING: Retrying (Retry(total=3, connect=None, read=None, redirect=None, status=None)) after connection broken by 'NewConnectionError(': Failed to establish a new connection: [Errno -3] Temporary failure in name resolution')': /simple/yfinance/
WARNING: Retrying (Retry(total=2, connect=None, read=None, redirect=None, status=None)) after connection broken by 'NewConnectionError(': Failed to establish a new connection: [Errno -3] Temporary failure in name resolution')': /simple/yfinance/
WARNING: Retrying (Retry(total=1, connect=None, read=None, redirect=None, status=None)) after connection broken by 'NewConnectionError(': Failed to establish a new connection: [Errno -3] Temporary failure in name resolution')': /simple/yfinance/
WARNING: Retrying (Retry(total=0, connect=None, read=None, redirect=None, status=None)) after connection broken by 'NewConnectionError(': Failed to establish a new connection: [Errno -3] Temporary failure in name resolution')': /simple/yfinance/
ERROR: Could not find a version that satisfies the requirement yfinance (from versions: none)
ERROR: No matching distribution found for yfinance
```
First, we install the `resolvconf` package.
```sh
sudo apt install resolvconf
```
Then, we activate and run the `resolvconf` service.
```sh
sudo systemctl enable resolvconf
sudo systemctl start resolvconf
sudo systemctl status resolvconf
```
Next, we enter the nameserver IP address in the **head** `resolvconf` configuration file.
```sh
sudo nano /etc/resolvconf/resolv.conf.d/head
```
```
nameserver 8.8.8.8
nameserver 8.8.4.4
```
After that, we run the `resolv.conf` update.
```sh
sudo resolvconf --enable-updates
sudo resolvconf -u
```
If an error like this occurs, then run the following command.
```
/etc/resolvconf/update.d/libc: Warning: /etc/resolv.conf is not a symbolic link to /run/resolvconf/resolv.conf
```
```sh
sudo dpkg-reconfigure resolvconf
```
Finally, we can verify by displaying the contents of the `resolv.conf` file.
```sh
cat /etc/resolv.conf
```
## Hardware Design
Now that we have configured the board, the next step is to try to create a basic hardware design. My hardware design consists of an AXI GPIO and an AXI DMA. The AXI GPIO is connected to 8 LEDs. The AXI DMA is connected to a looped-back AXIS FIFO.
The following figure shows the Zynq IP high-performance port configuration. The **S AXI HP0** and **S AXI HP2** interfaces are enabled.
The following figure shows the AXI DMA IP configuration.
The following figure shows the AXI GPIO IP configuration.
## Upload Design Files
To upload files, such as bitstreams, from the laptop to the board, you can use FileZilla via the Ethernet connection.
Required programs:
* FileZilla ()
The connections required are:
* Host: **192.168.1.99**
* Username: **xilinx**
* Password: **xilinx**
* Port: **22**
To upload the hardware design to PYNQ, you need to upload three files: `.bit`, `.tcl`, and `.hwh`.
## Python Program
The following notebook is used to test the hardware design. It consists of a Python program to test the AXI GPIO and the AXI DMA.
{% embed url="" %}
The results show that the AXI GPIO and AXI DMA can be accessed successfully.
## References
* Red Pitaya STEMlab 125-14,
* PYNQ for Redpitaya-125-14,
* Connect to your WiFi using Linux command line,
* How to Set Permanent resolv.conf on Ubuntu,
* Tutorial: PYNQ DMA (Part 1: Hardware design),
* Tutorial: PYNQ DMA (Part 2: Using the DMA from PYNQ),
