Guide for Raspberry Pi

Setup for "Bookworm"64/32bit, "Bullseye" 64/32bit and legacy "Buster" 32bit

The Raspberry Pi is a single board computer, which is very popular today. It is reliable and user friendly. It's electricity consumption is 5~7W depending on the setup and model. For staking is recommended to use the latest model Pi 5 or Pi 4b with at least 4GB RAM. Of course the previous Pi 3b+ still can be used, but in light of the upgrade of HYDRA blockchain to decreased block times a more powerful device will work much better.

What is more important, the native Operating System for the Pi is well supported and maintained by the Raspberry Pi Foundation and there are lots of materials online explaining how to setup the Pi and make different projects.

Our recommendation is to use the latest "Bookworm" 64 bit Pi OS or "Bullseye" 64 bit Pi OS.

Step 1 - Download the Pi OS and burn an image on a SD card.

Here is the link where you can get the official Raspberry Pi Operating Systems:

https://www.raspberrypi.com/software/operating-systems/

You can burn an image with the OS on a SD card (at least 32GB) using the Raspberry Pi Imager.

In case you plan to stake HYDRA, it is recommended to use the HYDRA Staking Wallet with GUI. Even advanced users can benefit from the GUI, because it is light and has useful features unavailable on the daemon version. If you intend to use the Staking Wallet with GUI then you will need a Raspberry Pi OS with desktop. The desktop can be viewed remotely using RealVNC server, which is installed on the Pi OS by default. RealVNC viewer can be downloaded from here.

If you are a developer and need to run a node for your app or you are a very experienced user, then you might want the daemon version of the HYDRA Staking Wallet, for which the Rapberry Pi Os Lite is appropriate.

It is highly recommended instead of a SD card to set up your Pi with a SSD. Then your HYDRA Staking node will be much faster and more reliable.

Brief instructions how to add a SSD to you Pi for new Bullseye OS installations:

1. Use the Raspberry Pi Imager to directly burn the latest OS Bullseye on a SSD using your desktop or laptop;

2. Remove the SD card from the Pi, plug in the SSD into a USB port and power on the Pi. The OS will load from the SSD;

3. Delete any partitions on your SD card with Mini Tool Partition Wizard. Power off the Pi, insert the SD card (the SSD stays plugged in) and turn on the Pi. The system will boot from the SSD and will be no longer trying to boot from the SD card. Done!

Adding a SSD for Bookworm OS installations is a bit more complicated. Here is a good guide how to do that: https://wiki.geekworm.com/X1002

A swap file is necessary even with 4GB RAM on the Pi, especially when syncing the blockchain. The syncing process is resource demanding. The recommendation is to set the swap file to 2048 MB size and swappiness to 10%

A proven guide how to set up the swap file and swappiness can be found in this article (Chapter 10): Raspberry Pi 4b - basic setup with Raspbian Buster and getting ready to install the staking wallet.

Step2 - Prepare the environment for running the wallet

• RaspberryPi OS Bookworm and Bullseye, 64 bit and 32 bit.

You may need to add the Berkeley database v4.8 libraries:

sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 8842CE5E
echo "deb http://ppa.launchpad.net/bitcoin/bitcoin/ubuntu artful main" | sudo tee -a /etc/apt/sources.list.d/bitcoin.list
sudo apt update
sudo apt install libdb4.8 libdb4.8++

Now skip the rest and go directly to Step 3 below.

• RaspberryPi OS Buster 32 bit.

It is necessary to add some missing dependencies, just follow the lines of code below:

First, add these libraries with this one single line:

sudo apt install libboost-system1.67.0 libboost-filesystem1.67.0 libboost-program-options1.67.0 libgmpxx4ldbl libboost-thread1.67.0 libboost-chrono1.67.0 libboost-random1.67.0 libprotobuf17 libevent-pthreads-2.1-6

Second, add the Berkeley DB ver 4.8 which is the recommended database to run for the wallet:

Add the missing repository using the nano editor:

sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 8842CE5E
sudo nano /etc/apt/sources.list.d/bitcoin.list

The last command from above will open the nano editor. Paste the following line inside the editor:

deb http://ppa.launchpad.net/bitcoin/bitcoin/ubuntu artful main

Now save the file with Ctrl-O and exit the nano editor with Ctrl-X

Add the Berkeley database v4.8 libraries:

sudo apt update
sudo apt install libdb4.8 libdb4.8++

Alternative way to add the Berkeley DB without using nano editor:

sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 8842CE5E
echo "deb http://ppa.launchpad.net/bitcoin/bitcoin/ubuntu artful main" | sudo tee -a /etc/apt/sources.list.d/bitcoin.list
sudo apt update
sudo apt install libdb4.8 libdb4.8++

Step 3 - Download the wallet

The latest release of the HYDRA Staking Wallets can be found on github here:

https://github.com/Hydra-Chain/node/releases

hydra-0.20.18-aarch64-linux-gnu.zip is for "Bookworm" 64 bit and "Bullseye" 64 bit;

hydra-0.20.18-arm-linux-gnueabihf.zip is for "Bookworm" 32 bit and "Bullseye" 32 bit.

The legacy file hydra-0.20.xx-raspberry-pi-legacy-32bit.zip for "Buster" 32 bit is not provided anymore. It's recommended to switch to the newest "Bookworm" 64bit or Bullseye" 64 bit Pi OS and use the correspinding HYDRA Staking Wallet file from above. More on the legacy OS version - here.

Create a directory called Hydra and download the zip file to it:

mkdir Hydra
cd Hydra
wget -N https://github.com/Hydra-Chain/node/releases/download/hydra_v0.20.18/hydra-0.20.18-aarch64-linux-gnu.zip

Replace the above link with the correct version for the Pi OS you use.

Step 4 - Unzip

Extract the archive

unzip -o hydra-0.20.18-aarch64-linux-gnu.zip

Your file may be named differently, depending on the OS version you use.

Step 5 - Run

The binaries will then be in ~/Hydra/bin/ where you can cd into with

cd ~/Hydra/bin/ 

Either run the command-line daemon (add '-testnet' if you wish to connect to testnet):

./hydrad -daemon

Call the daemon using (add '-testnet' if you are connected to testnet):

./hydra-cli getinfo

Or you can run the wallet with GUI (add '-testnet' if you are connecting to testnet):

./hydra-qt

The node runs on port TCP 13333 for testnet and TCP 3338 for mainnet. You may need to open these ports on the router and operating system firewall. For additional information please see this article about how to use the UFW (Uncomplicated Firewall) for Raspberry Pi.

Update the wallet on Raspberry PI

Please follow these steps:

• Close the wallet (./hydra-cli stop or clicking X in the Hydra gui)

• Ensure that you have a backup copy of your wallet.dat file and data folder (.hydra) before you proceed. Updating the client generally does not touch the wallet or blockchain data but it is good practise to always have the latest backup in case something goes wrong.

• Download the latest version for your operating system from https://github.com/Hydra-Chain/node/releases and replace the files in the corresponding folders.

• Voila! you've updated Hydra to the latest version available!

If you are updating your node and experience issues try starting with these flags to rebuild:

 -rescan -reindex

Links

The Webwallet can be found at: https://webwallet.hydrachain.org/

The Testnet Explorer can be viewed at: https://testexplorer.hydrachain.org/

The Testnet Faucet is at: https://faucet.hydrachain.org/

The Mainnet Explorer can be viewed at: https://explorer.hydachain.org/

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