HowTo: Monero node behind Tor with Oled display on a Raspberry Pi

I wanted to build a birthday present and what better than a plug and play Monero node on a Raspberry Pi. Right?

Disclaimer: I am a Linux noob and just fought my way through tutorials that i found on sites like http://pinode.co.uk/ (helped a lot. Thanks!) and similar. Encountered some bugs on the way, that is why i started this HowTo. For me to remember how i did it. And maybe it helps you over some bumps. If you want to follow my journey you will need rudimentary knowledge of the command line and javascript plus some patience. If you need a birthday present for next week, no chance.

List of components

• Raspberry Pi 3 (case + cooling etc. if you fancy)
• Power Source
• OLED display with i2c adapter like this
• MicroSD for Pi
• USB data storage with enough space for the Monero blockchain (i used a 256GB stick that i had spare)

Costs around 0.4 XMR.

End result

Setup Raspberry Pi

Follow the easily get started tutorial until you created the ssh file.

Connect over ssh

Look up ip on your network.
Start it headless with putty or ssh pi@{ip}.

Config

sudo raspi-config

Set new password for pi user!
Expand filesystem!

Update OS on Pi

sudo apt-get update
sudo apt-get upgrade

Move eveything to USB

I read that lot of read/write might destroy your card in the long run. Not 100% if this is needed but anyway:

Git is useful no matter what.

sudo apt-get install git

Plug in your device and find out where or what it is.

sudo lsblk

It's going to be /dev/sda, else you probably don't need this tutorial. Be sure you want the next step. Loss of data might occur.

sudo fdisk /dev/sda

d -> gone

w -> back

Ready for a helpful script from adafruit, i personally put it in a new folder called setup, just to keep an overview:

mkdir setup
cd setup
git clone https://github.com/adafruit/Adafruit-Pi-ExternalRoot-Helper.git
cd Adafruit-Pi-ExternalRoot-Helper
sudo ./adafruit-pi-externalroot-helper -d /dev/sda

Ahh the first error. Something something file system.

Got around it by reading https://github.com/adafruit/Adafruit-Pi-ExternalRoot-Helper/issues/5
and then using nano to edit the script and add that 5 second sleep. Do the same if you have the same error.

sudo nano adafruit-pi-externalroot-helper

106 info "fs create" "Creating ext4 filesystem on ${target_partition}"
107 + sleep 5
108 mkfs -t ext4 -L rootfs "${target_partition}"

sudo ./adafruit-pi-externalroot-helper -d /dev/sda again and yep it gives you a second chance to abort, but if you accept, it starts doing something without telling you exactly what.

Took 2 min for me, but be patient on older devices.

sudo blkid -o export /dev/sda1 to check out the PARTUUID.
sudo nano /boot/cmdline.txt​ and the root=PARTUUID= ... could show the one you just found. Else copy paste.

sudo reboot

Bäämmm the external devices blinks.

Run stuff without shutting it down when closing (screen)

Search online for an introduction to "screen" if you want to know more. There are lots. This one is not bad.

sudo apt-get install screen

then start a new screen

screen bash

and you can rejoin with

screen -r

screen is really useful and we will need it later.

Increase size of swapfile

sudo nano /etc/dphys-swapfile

edit the size of the swapfile from 100 to 1000

sudo dphys-swapfile setup
sudo dphys-swapfile swapon

Ready.

Finally Monero

A dependency we need:

sudo apt install libboost-all-dev

mkdir ~/bin
cd ~/bin

quick check if your OS is running 32 bit and make sure we need the ARMv7 Monero version:

lscpu

Output should look like

Model name: ARMv7 Processor rev 4 (v7l)

wget https://downloads.getmonero.org/cli/linuxarm7
tar -vxf ./linuxarm7

i found out, that if i start the monero daemon behind tor on a raspberry pi it will take a week or longer to sync. It is nice if you already have a raw blockchain from trusted source to import, else you can do

wget https://downloads.getmonero.org/blockchain.raw if you trust that source.

this is going to take a while ... depending on your download speed. Then:

./monero-blockchain-import --verify 0 --input-file ./blockchain.raw

now this is going to take around 4-5 days.

And then you could delete the raw blockchain:

rm -rf ./blockchain.raw

Some privacy please (TOR)

sudo apt-get install tor
sudo apt-get install tor-arm

sudo service tor status

looks goood. Let's create a password to monitor TOR later. And do not use PASSWORD pls.

tor --hash-password PASSWORD

Copy hash for pasting.

sudo nano /etc/tor/torrc

Big file, use ctr-w to find: #ControlPort 9051 - and remove the hashtag to activate it.
Same with HashedControlPassword and also paste your hash there.

sudo systemctl restart tor.service

this does what it says.

If you want to connect a local PC you can temporarily allow until next reboot with

sudo iptables -I OUTPUT -p tcp -d 127.0.0.1 -m tcp --dport 18081 -j ACCEPT

(add this to some startup routine if you need it permanently)

ARE YOU READY

Have your pi ip to fill out the xxx.xxx.xx in the next command and go for it.

DNS_PUBLIC=tcp TORSOCKS_ALLOW_INBOUND=1 torsocks ./monero-v0.11.1.0/monerod --p2p-bind-ip 127.0.0.1 --no-igd --rpc-bind-ip 192.xxx.xxx.xx --rpc-bind-port=18081 --confirm-external-bind --block-sync-size 10

Wait a little and shortly you will be happy to use ctr-a, release a and press d, and have the screen detached. screen -r to get back into it. (screen introduction already told you that, and similar tricks).

The sync from here will still take a couple of hours to days depending on how deep the raw blockchain went. If you are synching without blockchain import it could take forever. But i gave up on my first try after a few days.

Status

./bin/monero-v0.11.1.0/monerod --rpc-bind-ip 192.xxx.x.xx --rpc-bind-port 18081 status

with your ip to check on the status.

arm

to check on tor's status.

Shutdown

./bin/monero-v0.11.1.0/monerod --rpc-bind-ip 192.xxx.x.xx --rpc-bind-port 18081 exit

to shut monero down. And

sudo service tor stop

to shut tor down.

Start on boot

I tried different approaches but the boot process on raspberry has me suprised every time. Let's try this one that i found having regular success:

Create a startup script:

sudo nano ~/startup

and feed it our monerod on torsocks line:

DNS_PUBLIC=tcp TORSOCKS_ALLOW_INBOUND=1 torsocks /home/pi/bin/monero-v0.11.1.0/monerod --p2p-bind-ip 127.0.0.1 --no-igd --rpc-bind-ip 192.xxx.x.xx --rpc-bind-port=18081 --confirm-external-bind --block-sync-size 10

and do not forget to change it to match your ip.

Now we can start that script detached with screen from the rc.local (runs at the end of the boot process).

sudo nano /etc/rc.local

to do stuff on boot. Before exit 0 add:

... sleep 10 su - pi -c "screen -dm -S monerodscreen ~/startup" exit 0

The 10 second sleep is to give the raspberry time to finish some network duties before running torsocks. We run it in a screen named monerodscreen on a user called pi. Bingo.

Install and Config OLED display

Solder or wire up the OLED display as in instructions. I then glued the display to the transparent case from the inside.
Then you can follow this i2c tutorial.

After runnind the i2c-detect it looks like the OLED or something else is on:

 0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f

00: -- -- -- -- -- -- -- -- -- -- -- -- --
10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
30: -- -- -- -- -- -- -- -- -- -- -- -- 3c -- -- --
40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --

-> cx3c

cool.

Nodejs

i am not versed enough on linux to figure nodejs installation out by hand myself. But the awesome nodesource helps out with the oneliner:

curl -sL https://deb.nodesource.com/setup_9.x | sudo -E bash -

after that it is easy to install and you even get some info what you are doing:

sudo apt install nodejs

and then a quick

node -v

-> 9.4.0 (at the time of my installation)

A fancy nodejs with everything you need!

Monerod blockheight on the display

I was hoping to get the display to run on the oled-js-pi driver, but there were some bugs and i decided to fork the repository because there is no activity around it. Here is my repository with different bugs, but a script added to show height and status. It just requests the monerod rpc endpoint for height and shows this and the date, to make sure we are did not crash. If you have good ideas to improve this - please.

git clone https://github.com/nashequilibro/pi-oled-monero
cd pi-oled-monero
npm install

Now we are able to run it and the display should be showing the time and after successfully connecting to the daemon a status and blockheight. Those do update once a minute.

It takes one argument. The ip of the monero daemon running device.

node index xxx.xxx.xxx.xx

Add this to a new startup script if you wish (i called it startupmon), including the path to the index.js:

sudo nano ~/startupmon

add the line:

node /home/pi/pi-oled-monero/index xxx.xxx.xxx.xx

and then add the script to our startup routine:

sudo nano /etc/rc.local

and enter this line before exit 0:

su - pi -c "screen -dm -S oledscreen ~/startupmon"

and you have a monero node behind tor with a tiny little display. Both the display process and monerod run on screens in the background after startup. Check it out with screen -ls.

There was some heavy lifting necessary, but what i learned about the pi and monero was worth it. Took me around three weeks from scratch. Happy birthday!