# Ledger

Most of the time, the Ledger hardware devices work quite smoothly when connecting them to your computer.

For MacOS and Windows systems, the Ledger hardware devices should work smoothly out of the box. If not refer to the troubleshooting section just below.

If you are using a Linux-based system, please be sure that the udev rules are setup properly:

wget -q -O - https://raw.githubusercontent.com/LedgerHQ/udev-rules/master/add_udev_rules.sh | sudo bash

If you are experiencing connection problems with the Ledger device, it is worth trying a few things:

• Run the application as administrator (Windows)
• Enable full disk access (MacOS)
• Try a different USB cable or USB port (the originally packaged cable is best)
• Turn off any Anti-virus software or VPNs

The public repository for the IOTA Ledger app lives here. This can be used for...

• Running a Ledger Nano S or X hardware simulator
• Compiling and loading the app onto a Ledger Nano S

Additionaly, there is a legacy app, which is useful to test migrations. It lives here.

It is first necessary to install Docker (please see instructions). Alternatively, you can use these commands:

# MacOS
brew install docker

# Linux
sudo apt install docker docker.io

Next, clone the IOTA Ledger app repository:

git clone https://github.com/iotaledger/ledger-iota-app.git

In case of the Legacy app clone the following repository and check out the correct branch:

git clone https://github.com/shufps/app-iota-legacy.git
git checkout tmp_backport_docker

information_source: Pick a mnemonic from this spreadsheet and replace in app-iota-legacy/run_simulator.sh#64 after --seed (note the account index corresponds to the ledger index). Write your used seeds and ledger indexes here: https://hackmd.io/5MQxPS1jT6Cymtmpe6Sq_g?view If we run out of seeds, we have to ping Thomas to restart the network (and the used seeds should be cleaned up in the hackmd)

Change the following lines to use the simulator:

1. Under desktop/electron/lib/Ledger.js to await this.iota.setActiveSeed(`44'/4218'/${508396330 + index}'/${page}'`, security || 2)
2. Under desktop/electron/lib/Ledger.js to const USE_SIMULATOR = true

For using the simulator with migrations, change the following lines as well.

4. Under shared/lib/migration.ts to export const MIGRATION_NODES = ['https://api-legacy.migrator.h.potonet.if4testing.rocks']
5. Under shared/lib/migration.ts to return ['https://api.migrator.h.potonet.if4testing.rocks'])
6. Under shared/lib/migration.ts to export const ledgerSimulator = true

Rebuild desktop to apply the changes yarn build && yarn start

Once cloned, change directories, initialize Git submodules, and run the build script.

# initialize Git submodules
git submodule init
git submodule update --recursive

# run build script
sudo ./docker/build_docker.sh

After the Docker container is built, the simulator can be run with the following command:

sudo ./run_simulator.sh [-m (nanos|nanox)]

The -m argument is used to specify between the Ledger Nano S and Nano X (default is nanos).

After running, the simulator listens on port 9999 and can be used without restrictions with the ledger-iota.rs library.

ℹ️ When needing to change the mnemonic phrase used for the simulator, please adjust the line here after the --seed argument.

ℹ️ Only one simulator can be run at a time.

To compile and load the IOTA app on a real Ledger Nano S device, please use the following command:

sudo ./load_nanos.sh