1 Sun to USB keyboard protocol converter
2 ======================================
3 Target MCU is ATMega32u4 but other USB capable AVR will also work.
5 This converter will work with Sun Type 2-5 Keyboards.
9 Sun Type 3 Keyboard: http://blog.daveastels.com.s3-website-us-west-2.amazonaws.com/2014/12/27/type-3-keyboard.html
10 CTCSP SHORT TYPE KEYBOARD(Type 5): http://imgur.com/a/QIv6p
13 Keymap of Type 3(keymap_sun3.c) were impoted from dastels's repository.
14 https://github.com/dastels/tmk_keyboard/tree/master/converter/sun3_usb
31 ----------------------------------
44 Signal: Asynchronous, Negative logic, 1200baud, No Flow control
45 Frame format: 1-Start bit, 8-Data bits, No-Parity, 1-Stop bit
47 AVR USART engine expects positive logic while Sun keyboard signal is negative.
48 To use AVR UART engine you need external inverter in front of RX and TX pin.
49 Otherwise you can software serial routine to communicate the keyboard.
51 This converter uses software method by default, so you don't need any inverter part. But
52 it can also be built with 'make HARDWARE_SERIAL=y' to enable hardware serial if there
53 is an inverter present. Good results have been obtained using a 74LS04 and hardware serial.
56 Commands From System To Keyboard
58 Keyboard responds with following byte sequence:
59 Success: 0xFF 0x04 0x7F
66 followed by LED status byte:
68 LED: CapsLk ScrLk Compose NumLk
70 Keyboard responds with 'Layout Response' 0xFE 0xXX
72 Commands From Keyboard To System
74 means no keys pressed.
76 0xFF Reset Response(followed by 0x04)
79 http://kentie.net/article/sunkbd/page2.htm
80 http://kentie.net/article/sunkbd/KBD.pdf
88 Then, load the binary to MCU with your favorite programmer.
93 You can send Sun protocol commands with TMK `Magic` key combo. By default `Magic` key is `LShift` + `RShift`, `LAlt` + `RAlt' or `LMeta` + `RMeta`.
94 https://github.com/tmk/tmk_keyboard#magic-commands
96 Following Sun specific commands are available. For example, to send 'Bell On' you can press `LShift` + `RShift` + `Up` keys simultaneously.
99 ----- Sun converter Help -----