Lamp-Da

A compact lantern project.

This repository contains the software and PCB files to create a compact lantern, composed of a led strip wrapped around a 50mm cylinder.

The code is not designed to be the most readable but to be robust, so it can be quite tricky to understand, sorry !

Behavior

base behavior:

• The lamp starts and stops with one click.
• The luminosity can be raised by clicking than holding, and diminished by double-clicking than holding.

The battery level is displayed as a color gradient from green (high) to red (low).

Error and alerts are displayed as blinking animations:

• low battery: slow red blinks
• critical battery: fast red blinks, emergency shutdown
• charging: breeze animation, changing color to reflect battery level
• incoherent battery readings: fast green blinks
• main loop too slow: fast fushia blinks
• temperature too high: fast orange blinks
• temperature extreme: emergency shutdown
• bluetooth advertising: blue breeze animation
• unhandled: fast white blinks

User defined behaviors

The user MUST define the target behavior for the target uses.

Some functions are defined in functions.h files, and must be implemented in functions.cpp They allow the user to program the exact desired behavior.

Some user types are available for base models, in the user folder:

• cct: Program designed for a constant color temperature led strip.
• indexable: program designed for an indexable led strip wrapped around the lamp body
• simple: Program designed for a constant color led strip

Above: simple, cct, indexable

File details

• Lamp-Da.ino: main class of the program, containing the setup and loop functions

Physical build and architecture :

The electrical circuit and build files can be found in the electrical folder.

The PCB can be ordered directly assembled from JLC PCB, for a total cost of around 270$ for the minimal 5 pieces command (price drops with a more commands, until around 11$/circuit).

The circuit is 4 cells li-ion USB C charger, that is also programmable via the same USB port. It features a constant current strip that can be as high as continuous 2.3A, controlled by PWM.

The circuit features:

• USB-C 4S li-ion charger, based on BQ25703A ic.

• USB short circuit and EC protection, based on TPD8S300 ic.

• USB-C power negotiation, base on FUSB302 ic.

• Constant current led driver, that can maintain stable up to 2.3A, based on LM3409HV ic.

• 9 programmable IO pins (4 of which can be analog inputs, 4 can be pwm outputs). Based on nRF52840 ic.

• MEMS Microphone, placed away from parasitic ringing components.

• LSM6DS3TR IMU, placed on the exact center so the axis alignment is easy.

• Bluetooth 5.1 low power, with correct 5/10m range.

• Multiple protection features (ESD spikes protection, USB voltage snubber, USB voltage limitation, ...)

Be careful:

• NO REVERSE VOLTAGE PROTECTION FOR BATTERY: it will blow the circuit right up
• IO are 3.3V max, any voltage greater will destroy the system

How to program

Out of factory, the system will miss a bootloader.

You can flash a bootloader using the IO | CL pads on the board, with a JTAG probe, or an open source solution described below:

Once the bootloader is written, the microcontroller can be programmed via USB, using the Arduino IDE or any flashing program.

Bootloader flash

• Use a raspberry of any other linux system with gpios
• Use the open source program openocd as described in this post

Building the project

The supported platform to work with the project is:

• Linux (Debian/Ubuntu/Archlinux/etc) with Arduino 2.0 or later

Installing dependencies

You will need to:

• Install the Arduino IDE and verify that arduino-cli is accessible in path
• Install the Adafruit nRF52 board support (version 1.6.1) as described here
• Replace the content of the $HOME/.arduino15/packages/adafruit/hardware/nrf52 by the content of the above repository
• Install adafruit-nrfutil from PyPI
• Install the Adafruit Neopixel and arduinofft libraries

Alternatively, at the cost of some additional disk space, you may use the provided Makefile to install all dependencies:

git clone "https://github.com/BaptisteHudyma" LampColorControler
cd LampColorControler
make mr_proper arduino-cli-download safe-install

This will install everything in the $SRC_DIR/_build/arduino-cli/ directory.

Quick setup

First clone the repository:

git clone "https://github.com/BaptisteHudyma" LampColorControler
cd LampColorControler
make

As highlighted above, this project uses Arduino platform, you will need to install Arduino before continuing to the next step.

Then, check that arduino-cli is available in path:

arduino-cli version

If arduino-cli is available and you find yourself in trouble installing the dependencies by hand, you can use:

# download+install all dependencies (~1.4Go) in $SRC_DIR/_build/arduino-cli/
cd LampColorControler
make safe-install

If your system does not package arduino-cli or if you're not satisfied with its packaging, you may try:

# also download+install arduino-cli in $SRC_DIR/_build/arduino-cli/
cd LampColorControler
make arduino-cli-download safe-install

You will then be able to build the project as follows:

# build project assuming {simple,cct,indexable} lamp type
cd LampColorControler
make simple

After plugging your board, you should be able to upload as follows:

# upload to board using the upload-{simple,cct,indexable} target
cd LampColorControler
make upload-simple

If you need to configure the serial port of the board before upload, use:

# by default LMBD_SERIAL_PORT is /dev/ttyACM0
cd LampColorControler
LMBD_SERIAL_PORT=/dev/ttyACM1 make upload-simple

Once your board is running, to connect to its serial monitor, use:

# use LMBD_SERIAL_PORT as above to configure the serial port
cd LampColorControler
make monitor

To build the documentation, you must have doxygen installed:

# use "make clean-doc doc" to force documentation rebuild
cd LampColorControler
make doc

When changing lamp type or adding a new file to the sketch, use:

# use "make clean-artifacts" to remove the output binary artifact
cd LampColorControler
make clean
make indexable

If you have a virtualenv somewhere with adafruit-nrfutil already installed, you may setup a link to explicitly use it:

# the Makefile will source $SRC_DIR/venv/bin/activate
cd LampColorControler
ln -s venv path/to/other/virtualenv
make clean-artifacts upload-indexable

If you want simulate a view of an "indexable mode" animation and have the SFML installed:

cd LampColorControler
make simulator
./_build/simulator/*-simulator

If you want to work with "indexable mode" simulator, add your custom $NAME simulation in $(SRC_DIR)/simulator/src/$NAME-simulator.cpp then build with:

cd LampColorControler
make clean-simulator $NAME-simulator
./_build/simulator/$NAME-simulator

Once you're finished with your work on the project:

# this removes build artifacts AND all local dependencies
cd LampColorControler
make mr_proper

How the build system works?

We are relying on Arduino and Adafruit's integrations to do a lot of things. We want to use modern compiler features and some customization to our setup, while we don't want to modify how Adafruit's platform core and libraries are build.

On first build, we will thus first:

0. compile a "clean" build-clean target later used to detect how Arduino builds our sketch

Then, on all subsequent builds:

1. compile a "dry" build-dry target which will build core+libraries with the default setup
2. rebuild the sketch objects using our own custom setup (C++17, other flags)
3. compile a "final" build target which will let the arduino-cli reuse all the already-build objects, to produce a final artifact

This is a hack and sanity checks are in place to verify that the sketch have been properly build (see make verify-canary)