Simple PWM controller
=====================

`https://bues.ch/cgit/simplepwm.git/ <https://bues.ch/cgit/simplepwm.git/>`_

Simplepwm is a small PWM brightness controller for LED lamps.


Microcontroller
===============

Simplepwm supports these microcontrollers:

Atmel/Microchip ATTiny 25/45/85:

* Full feature set.

Atmel/Microchip ATTiny 13:

* Reduced feature set.
* No battery power saving.
* No battery voltage monitoring.


Hardware schematics
===================

See `schematics/simplepwm.pdf <schematics/simplepwm.pdf>`_


Prebuilt firmware images
========================

The release archives of simplepwm contain prebuilt `.hex` files for all supported microcontrollers in the `hex` directory. These hex files can be flashed directly to the microcontroller with a any tool of your choice (e.g. Atmel Studio or avrdude).

The corresponding fuse settings can be found in the file `fuses.txt` in the same directory.


Building the firmware
=====================

The firmware build needs the following tool chain:

* Unix-like operating system
* GNU make
* AVR GCC
* AVR Binutils
* avrdude

Run the following commands to build the firmware:

.. code:: sh

	cd firmware
	make DEV=t85

Please specify the target microcontroller using the DEV variable as shown above.

Valid values are:

* ATTiny 13: `DEV=t13`
* ATTiny 25: `DEV=t25`
* ATTiny 45: `DEV=t45`
* ATTiny 85: `DEV=t85`


Flashing the firmware after build
=================================

Run the following commands to flash the firmware to the target microcontroller:

.. code:: sh

	cd firmware
	make DEV=t85 print_fuses
	make DEV=t85 write_fuses
	make DEV=t85 write_mem

Or alternatively use any other of the available AVR flashing tools to program the .hex file and fuses.


License
=======

Copyright (c) 2018-2020 Michael Buesch <m@bues.ch>

This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.