For full info and docs, see http://heepy.net/index.php/USB-teletype
quickstart:
signal from loop is received on PD4, signal toward loop output on PD6 LED indicators are on D0 and D1, currently D0 shows outbound data and D1 shows inbound.
To work with custom board, the default avr dfu bootloader has to be replaced with a different one that doesn't need HWB brought out.
Set the fuses:
avrdude -p atmega16u2 -P /dev/ttyACM0 -c stk500v2 -e -U hfuse:w:0xd0:m avrdude -p atmega16u2 -P /dev/ttyACM0 -c stk500v2 -e -U lfuse:w:0xde:m
Install the bootloader:
cd ~/git/avr-lufa/lufa/Bootloaders/CDC/ make clean; make Connect ISP programmer and run: avrdude -p atmega16u2 -P /dev/ttyACM0 -c stk500v2 -e -U flash:w:BootloaderCDC.hex
Install this software: Remove ISP programmer, connect only USB cable. cd ~/git/avr-lufa/lufa_serial/ make clean; make make program
If you program it using the ISP programmer afterward, you'll need to reinstall the bootloader too.
This is an attempt to get a useful USB CDC ACM endpoint on AVR using the latest LUFA USB stack. Eventual target is atmega32u2 so I can use it on the usb-to-tty loop adapter board. Compiles and works correctly on both 32u2 and 32u4.
It needs the current LUFA distro from http://www.github.com/abcminiuser/lufa/archive/LUFA-151115.zip unzipped into ../lufa
epv 2/11/2016
2/13/16 added softuart from usbtty2 project. Sending and receiving work fine.
added test stuff to switch to and from commandline mode using "%"
still need to do:
- actual config mode: (implemented, still adding to it)
translating vs transparent mode, so you can use it with HeavyMetal in place of cp2102 (done) enable/disable auto-cr, cr->crlf (not sure i care) set auto-cr column? (later) select character set maps? (later) speed? Might be able to set baud rate just by setting OCR1A = 83333 / baudrate (done)
16000000 / 64 / (3 * 45.45) = 1833 // 60 WPM 16000000 / 64 / (3 * 50.00) = 1667 // 66 WPM 16000000 / 64 / (3 * 56.90) = 1464 // 75 WPM 16000000 / 64 / (3 * 74.20) = 1123 // 100 WPM
Maybe a setting for inverting or not inverting the RX and/or TX sense? (not sure i care)
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implement unshift on space, i think (done)
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switch to/from config mode by hardware button vs "%" key. (done)
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ASCII mode for m33's. (implemented, appears to work with linux serial port, no 33 to test with, need more framing info) also no idea how real machines handle or don't handle parity.