μ [sic] design constraints wesley :: chris :: dave :: josh

:: project overview wireless home media solution consists of base station & portable media drives base station detects drives within range media files will be streamed from drives to base station base station will output analog audio signal at line level

:: hardware components base station microcontroller portable drive microcontrollers base station mp3 decoder wireless transceivers base & portable memory portable drive batteries base station LCD screen

:: base station µ constraints 8 bit processor –maintain low cost –more bits unnecessary SPI port for four slaves –LCD, mp3 decoder, wireless, flash memory general input/output pins –at least 6 inputs for user controls –at least 4 outputs for status LEDs flash memory –9 KB for filesystem library –15 KB for application space 2 KB RAM for filesystem buffering clock –preferably internal & programmable –minimum 5 MHz (128 x 2 kHz for SPI x 20 to be safe) “reasonable” power consumption

:: mp3 decoder considerations STMicroelectronics STA013 VLSI Solution VS1003B-L details MP3 decoding (up to 320 kbps, 48 kHz), digital volume control, bass & treble control MP3 & WMA decoding (up to 384 kbps, 48 kHz), bass & treble controls, on-chip stereo DAC, 2.8 V package SO 28, TQFP 44LQFP 48 cost $ $24.00

:: base station µ finalists Atmel AT89C51SND1C Atmel ATmega32 Atmel ATmega644 clock 20 MHz max, on- chip oscillator & PLL 16 MHz max20 MHz max, 8 MHz oscillator on chip flash 64 K32 K64 K RAM > 2 K2 K4 K ports SPI & PCM audioSPI i/o up to 44up to 32 voltage V V > 4 MHz package TQFP 80TQFP 44, PDIP 40 bonus on-chip MP3 decoder cost $15.48$8.17$7.87

:: portable drive µ constraints 8 bit processor –maintain low cost –more bits unnecessary SPI port for two slaves –wireless & flash memory general input/output pins –at least 2 inputs for user controls –up to 8 outputs for status LEDs flash memory –9 KB for filesystem library –10 KB for application space 2 KB RAM for filesystem buffering clock –preferably internal & programmable –minimum 2.5 MHz (128 x 2 kHz for SPI x 10 to be safe) lowest available power consumption

:: portable drive µ finalists Atmel ATmega32 Atmel ATmega644 clock 16 MHz max20 MHz max, 8 MHz oscillator on chip flash 32 K64 K RAM 2 K4 K ports SPI i/o up to 32 voltage V < 4 MHz package TQFP 44, PDIP 40 cost $8.17$7.87

:: end

:: revisited pssc 1.an ability to decode an MP3 file into a stereo, line-level analog output signal 2.an ability to read FAT16 files stored on an SD memory card 3.an ability to wirelessly transmit data from a plurality of handheld devices to a single base station 4.an ability to wirelessly detect active wireless handheld devices within close proximity and request MP3 files from them 5.an ability to display operational status on base station LCD