an audio amplifier project that contains a mixer controlled by an MSP430 microcontroller contents: hardware/power_amp - power circuit for the amplifier hardware/power_pre - power circuit used by the mixer board hardware/amp - 2x25W amplifier. for a quad setup this board is used twice, for 6 channels it's used 3 times. hardware/mixer - mixer board. 10 inputs, 6 outputs, 12 channels of mixing. a stereo-to-quad panning circuit is included firmware_mixer - software that runs on the MSP430F5510 that is present on the mixer board firmware_brain - software for the main uC (CC430F5137) that interfaces the user with the mixer board. currently user input comes via remote control presses. firmware_display - software that runs on the atmega present on the BADGEr. this is a simple adaptation on Jeremy Blum's "Pi BADGEr ePaper Weather Station". linux - linux client that talks over a serial link to firmware_brain and controls the mixer and the power amp pictures now available: https://photos.app.goo.gl/L8txqSKrcZFV2BbR8 -------------------------------------------- Mixer board input two different input methods are available, either via UART or I2C. since they use the exact same 2 pins the switch between them is a compile time option - see config.h. the i2c interface is highly recommended. I2C implementation the communication protocol consists of either a direct 14 byte read in which case the current settings are being shared, 2 byte writes for sending commands or 4 byte writes for sending new volume values. the slave address is 0x28. UART commands v___ set volume ||+ volume - [0-255] |+- channel - {r,l,b} +-- pga ID - [1-6] 1: front, 2: rear, 3: line-in 4: spdif, 5: front-rear pan, 6: center and subwoofer m_ mute pga +- pga ID - [1-6] u_ unmute pga +- pga ID - [1-6] w_ write current settings to flash +- location [1-3] r_ load saved settings from flash +- location [1-3] s show settings ? show help homepage: https://github.com/rodan/ampy author: Petre Rodan <2b4eda@subdimension.ro> license: GNU GPLv3 parts of the code were originally forked from the openchronos-ng project [1]. linux mixer control code based on alsamixer [2] software requirements: msp430 toolchain [1] http://openchronos-ng.sourceforge.net [2] http://www.alsa-project.org