A small node app that is meant to run on a single-board computer and securely connects a physical lab device to a remote bionet node. Currently only 2D barcode label scanners and printers are supported.

Specifically, the following device-types are supported:

• USB barcode scanners that show up as a keyboard
• Plain USB webcams (for scanning DataMatrix codes only)
• USB thermal label printers (Brother QL-570 or QL-700)

For printers this allows printing from the bionet web app to in-lab thermal printers.

For scanners this makes it possible to show scan results in the bionet web app when scanning on in-lab barcode scanners.

Connections are made using ssh2.

Supported barcode scanners

• Any USB scanner that shows up as a USB keyboard (e.g. Kercan KR-201)
• Any USB scanner that shows up as a webcam (e.g. SUMLUNG scanners from ebay/aliexpress)

Supported shipping label printers

• Dymo LabelWriter 4XL

Supported QR-code label printers

• Brother QL-570
• Brother QL-700

Other similar models may work but have not been tested.

Dependencies

installing node.js

You might already have node.js installed. If so, ensure it is a recent version. If not, first log in as the non-root user you intend to run this application, then install nvm (node version manager):

curl -o- https://raw.githubusercontent.com/creationix/nvm/v0.31.2/install.sh | bash

Log out, then log back in, then use nvm to install node:

nvm install 6.10 # or whatever the latest LTS release of node is

Now clone this repository into the user's homedir:

cd ~/
git clone https://github.com/biobricks/bionet-labdevice

To install the node dependencies do:

cd bionet-labdevice/
npm install

bluetooth dependencies

For bluetooth support install:

sudo apt install bluetooth bluez libbluetooth-dev libudev-dev libcap2-bin

Then grant your node.js binary the cap_net_raw privilege to allow it to control the bluetooth chip without being run as root. As the user that will be running this program, run:

which node

and ctrl-c the output.

Then as root run:

setcap cap_net_raw+eip $(eval readlink -f <node_path>)

where <node_path> is the output from the which node command.

printer driver dependencies

If you're using this with a printer install the C program that talks to the printer, fetch the ql-printer-driver repository:

git clone https://github.com/biobricks/ql-printer-driver

and follow the instructions in the included README.md

webcam scanner dependencies

If you're using this with a webcam-based barcode scanner, install these packages:

sudo apt install streamer dmtx-utils v4l-utils

The streamer utility captures single frames from the webcam. dmtx-utils provides the dmtxread command that decodes DataMatrix codes from the captured image and v4l-utils sets the brightness and contrast of the webcam.

HID/keyboard scanner dependencies

If you're using this with a USB barcode scanner that pretends to be a USB keyboard (most hand-held type USB barcode scanners are like this) then you might need:

sudo apt install build-essential git gcc-4.8 g++-4.8 libusb-1.0-0 libusb-1.0-0-dev

Generate key pair

cd /home/bionet/bionet-labdevice # ensure you are in the app directory
ssh-keygen -t rsa -f mykey -N ""

Setup

Copy the examples settings file:

cp settings.js.example settings.js

and edit to taste.

You get the correct hosthash by running this with the wrong hosthash and the correct hostname and port.

Permissions

If you're using a printer or webcam type device, ensure your user has write access to the device defined in the settings file. On ubuntu/debian systems you can do this using:

sudo usermod -a -G lp myUser # for printers
sudo usermod -a -G video myUser # for webcams

Where myUser is the username of the user that will be runnning this program. You will have to log out and log back in for the change to take effect.

Finally, ensure that the generated private key is only readable by root and the user that will be running the this program.

Running

Then run:

npm start

Testing

For printers you can test this client using bin/print_server_test.js from the main bionet app.

Setting up for production

The bionet-labdevice software should be installed under a non-root user account, so as root add a user account, e.g:

adduser bionet

Then log in as that user, ensure you are in the user's homedir and follow the instructions at the top of the README for installing this application and its dependencies.

Now for making the app auto start when the computer boots and auto restart when it crashes.

First install the psy process monitor globally:

npm install -g psy

Then as root:

sudo cp production/bionet-labdevice.initd /etc/init.d/bionet-labdevice
chmod 755 /etc/init.d/bionet-labdevice

If you used a different username than bionet then you'll need to change the runAsUser line in the init.d file.

Test that it works. As root do:

systemctl daemon-reload # only if using systemd
/etc/init.d/bionet-labdevice start

If it's working make it auto-start on reboot:

update-rc.d bionet-labdevice defaults

ToDo

• Start as root, read private key, then drop permissions
• Report USB connection status
• Hook BLE scanning into the RPC system
• Implement remote software update

License and Copyright

License is GPLv3

• Copyright 2016, 2017, 2018 BioBricks Foundation