TribeDuino is a proof of concept that uses an Arduino to read a Korg Monotribe audio-encoded firmware file. It doesn't do anything with the data except calculate a checksum to prove that it read it correctly. The program works by connecting an Arduino to an MP3 player of some kind via an audio patch cable, and then playing the firmware audio file so that the Arduino can hear it.
UPDATE: Want to program Arduinos with sound? See Audioino!
The firmware uses frequency-shift keying, or FSK, to encode its data. In FSK, you pick a point on a sine wave (like the peak), and measure how much time elapses between peaks. Over time, variations in the peak-to-peak period represent data. The Korg firmware uses binary FSK, which means that there are only two possible period lengths. A short period is a binary one, and a long period is a binary zero.
There is a 342-short-bit gap between packets that would seem pointless for a PC that's decoding the sound file offline. But for an Arduino or Monotribe that is reading the audio stream real-time, it's a much-needed 75-millisecond break during which the device can do something interesting with the packet it just decoded, such as writing it to flash memory, without falling behind for the next packet.
The effective bitrate is very close to 2400 baud (calculated using a 33,024-byte final firmware file, 8 bits per byte, and an audio runtime of about 1:50). That figure is not entirely comparable to a real 2400-baud modem for various reasons.
InstructionsRead More and get files at sowbug/TribeDuino - GitHub...
It is possible to load a program into an AVR-microcontroller over the audio interface of a PC or laptop:
The bootloader presented here has the following features:
- automatic Baudrate detection and calibration
- works without calibration with 8Mhz or 16MHz sysclk ( possibly 1MHz, not tested )
- very simply hardware circuit: 2 resistors and a 100nF capacitor to connect to the audio line
- only one pin for data transmission needed and an additional pin for a status led
- low memory footprint: 800 bytes
- java program to generate the sound, works on win and Linux
As line coding scheme Manchester-coding is used. With this type of coding we achieve only half the transmission speed than with "Flankenkodierung" used in Soundrxtx. Therefore the mean value of the signal is more stable and no calibration potientiometer is needed.
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- Cool Stuff!:) I wonder if this would work on a TI MSP-EXP430FR5739? That's all I have to work with...
- Programming an Arduino using an audio file
- Programming an Arduino using an audio file - Hack a Day
- sowbug/TribeDuino - GitHub
- Program an Arduino using your sound card - Hack a Day
- forum.hobby-roboter.de • View topic - Audio Bootloader
- Reverse engineering a Korg Monotribe - Hack a Day
- Microcontroller comm with a computer monitor - Hack a Day