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 ATTiny-85 ATTiny-45 ATTiny-25 ATTiny-13
Number of analog pot. inputs 3 1 1 1 1
Number of PWM outputs 3 1 1 1 1
Battery power saving x x x    
Battery voltage monitoring x x x    
HSL color model x        
Remote control via UART x        
Debugging via UART 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:

Run the following commands to build the firmware:

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 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:

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.