simplepwm

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

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

Simplepwm is a small PWM brightness controller for LED lamps.


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

Simplepwm supports the following microcontrollers. Not all features are supported on all microcontrollers. See the table for details.

============================ =========== ========== ========= ========= ========= =========
.. ATMega-328P ATMega-88P ATTiny-85 ATTiny-45 ATTiny-25 ATTiny-13
============================ =========== ========== ========= ========= ========= =========
Number of analog pot. inputs 3 3 1 1 1 1
Number of PWM outputs 3 3 1 1 1 1
Battery power saving x x x x
Battery voltage monitoring x x x x
HSL color model x x
Debugging via UART x x
============================ =========== ========== ========= ========= ========= =========


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

Schematics for ATMega based setups: `schematics-atmega/simplepwm-atmega.pdf `_

Schematics for ATTiny based setups: `schematics-attiny/simplepwm-attiny.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:

=============== ===========
Microcontroller make option
=============== ===========
ATTiny 13 `DEV=t13`
ATTiny 25 `DEV=t25`
ATTiny 45 `DEV=t45`
ATTiny 85 `DEV=t85`
ATMega 88P `DEV=m88p`
ATMega 328P `DEV=m328p`
=============== ===========

Additional build options that can be passed to `make`:

=========== ====== ======= ================================================================
make option values default description
=========== ====== ======= ================================================================
PWM_LIM 1-100 100 Limit the maximum PWM duty cycle to this percentage.
PWM_INVERT 0-1 0 Invert the PWM output signal(s).
ADC_INVERT 0-1 0 Invert the ADC input signal(s).
ADC_HSL 0-1 1 Interpret the ADC input signals as HSL setpoints instead of RGB.
=========== ====== ======= ================================================================


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

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.