Meeting room displays

Bluetooth mesh based long lasting meeting room displays.

This repository provides the code for the displays as well as the server application that fetches the meeting room appointments from an office 365 calendar and sends the information to the configured displays. The server application will use a usb dongle to send the data to the displays.

Hardware

The dongle used for the server application is the Nordic nRF52840 Dongle: https://www.nordicsemi.com/Software-and-tools/Development-Kits/nRF52840-Dongle

The displays use the Nordic nRF52840 DK: https://www.nordicsemi.com/Software-and-Tools/Development-Kits/nRF52840-DK

and the waveshare 7.5 inch e-paper HAT: https://www.waveshare.com/wiki/7.5inch_e-Paper_HAT

please note that at the moment only revision 1 of the e-Paper HAT is working.

Checkout and init

The project is based on zephyr RTOS. To clone this repository as well as everything needed call:

west init -m https://github.com/TobiasSchaffner/meeting_room_displays.git
west update

Udev rule

To make it easier to flash the dongle it is recommended to apply the provided Udev rule. It will create a symlink which will always have the same name no matter which ttyACM enumeration it got.

sudo cp meeting_room_displays/20_DiplayDongleUDev.rules /etc/udev/rules.d/
sudo udevadm control --reload-rules && sudo udevadm trigger

Installing Zephyr SDK

To install the SDK follow the steps provided in the official Zephyr documentation.

Installing nrfutil

In order to flash the Nordic dongle the nrfutil package is required. Install it via pip:

pip install nrfutil

Install nrfjprog

nrfjprog is required to flash/debug the nRF52840 development kit (in this case: the display). Download the tool here. Debian based systems may install the .deb package via

sudo dpkg -i <nrf-debian-package-name>.deb

nrfjprog requires SEGGER's JLink Software in order to run. Download the appropriate installer for your system here. As in the previous step, Debian based systems may use the .deb and install it the same way as above.

Adding the user to the dialout group

Make sure to add the user who is working on this project to the dialout group so that she can access /dev/<tty-device> (eg. the dongle):

sudo usermod -a -G dialout <username>

Do not forget to start a new terminal afterwards.

Build

To build one of the components use the provided make file in meeting_room_displays/app/

E.g. to build and flash a display call:

make display

To build and flash the dongle: Insert the dongle into a USB port and press the reset button. A red LED will light up. Then call:

make dongle

Issues

Sometimes the udev rule won't work and ttyDisplayDongle won't show up in /dev/. In that case uncomment the section at the very bottom in app/Makefile.