diff --git a/converter/m0110_usb/Makefile b/converter/m0110_usb/Makefile index 66eae880f4..f1c51e1bb5 100644 --- a/converter/m0110_usb/Makefile +++ b/converter/m0110_usb/Makefile @@ -71,7 +71,7 @@ OPT_DEFS += -DBOOTLOADER_SIZE=4096 # Build Options # *Comment out* to disable the options. # -#BOOTMAGIC_ENABLE = yes # Virtual DIP switch configuration(+1000) +BOOTMAGIC_ENABLE = yes # Virtual DIP switch configuration(+1000) MOUSEKEY_ENABLE = yes # Mouse keys(+4700) EXTRAKEY_ENABLE = yes # Audio control and System control(+450) CONSOLE_ENABLE = yes # Console for debug(+400) diff --git a/converter/m0110_usb/README.md b/converter/m0110_usb/README.md index bd8bef9f21..b3fb8f7e97 100644 --- a/converter/m0110_usb/README.md +++ b/converter/m0110_usb/README.md @@ -1,10 +1,12 @@ M0110/M0110A to USB keyboard converter ====================================== -This firmware converts the protocol of Apple Macintosh keyboard M0110/M0110A into USB. -Target board of this project is [PJRC Teensy](http://www.pjrc.com/teensy/), though, -you can use other board with USB AVR like `ATmega32U4` and `AT90USB`. +This firmware converts the protocol of Apple Macintosh keyboard **M0110**, **M0110A** and **M0120** into USB. Target of this project is USB AVR controller **ATmega32U4**. Using this converter you can revive these retro keyboards with modern computer. + +Pics of **M0110 + M0120** and **M0110A**. + +![M0110+M0120](http://i.imgur.com/dyvXb2Tm.jpg) +![M0110A](http://i.imgur.com/HuHOEoHm.jpg) -![M0110](https://raw.github.com/tmk/tmk_keyboard/master/converter/m0110_usb/doc/m0110.jpg) - M0110A support was contributed by [skagon@github](https://github.com/skagon). - M0120 also is supported. keys(+ * / and ,) on M0120 are recognized as cursor keys. @@ -13,49 +15,42 @@ you can use other board with USB AVR like `ATmega32U4` and `AT90USB`. Update ------ -- 2013/08 Change port for signals PF to PD +- 2013/08: Change port for signals `PF` to `PD` +- 2013/09: Change port again, it uses inversely `PD0` for data and `PD1` for clock line now. -Connection ----------- -You need 4P4C plug and cable to connect Teensy or other AVR dev board into the keyboard. -Teensy port `PD0` is assigned for `CLOCK` line and `PD1` for `DATA` by default, -you can change pin configuration with editing *config.h*. +Building Hardware +----------------- +You need **4P4C** cable and **ATMega32U4** board like PJRC [Teensy]. Port of the MCU `PD1` is assigned to `CLOCK` line and `PD0` to `DATA` by default, you can change pin configuration with editing `config.h`. -You can find 4P4C plugs on telephone handset cable. Note that it is *crossover* connection -while Macintosh keyboard cable is *straight*. +[![M0110 Converter](http://i.imgur.com/4G2ZOegm.jpg)](http://i.imgur.com/4G2ZOeg.jpg) -[![Conection](https://raw.github.com/tmk/tmk_keyboard/master/converter/m0110_usb/doc/teensy.jpg)] +### 4P4C phone handset cable +Note that original cable used with Mac is **straight** while phone handset cable is **crossover**. -In this pic: + -1. `GND`(Black) -2. `CLOCK`(Red) -3. `DATA`(Green) -4. `+5V`(Yellow) +Close-up pic of handset cable. You can see one end of plug has reverse color codes against the other. Click to enlarge. +[![4P4C cable](http://i.imgur.com/3S9P1mYm.jpg?1)](http://i.imgur.com/3S9P1mY.jpg?1) -Note that wire colors may vary in your cable. +[Teensy]: http://www.pjrc.com/teensy/ -### Pinout +### Socket Pinout - -- ![Jack fig](http://www.kbdbabel.org/conn/kbd_connector_macplus.png) ### Pull-up Registor -You may need pull-up registors on signal lines(`CLOCK`, `DATA`) in particular -when you have long or coiled cable. 1k-10k Ohm will be OK for this purpose. -In some cases MCU can't read signal from keyboard correctly without pull-up resistors. +You may need pull-up registors on signal lines(`CLOCK`, `DATA`) in particular when you have long or coiled cable. **1k-10k Ohm** will be OK for this purpose. In that case the converter may not read signal from keyboard correctly without pull-up resistors. Building Frimware ----------------- -To compile firmware you need AVR GCC. You can use [WinAVR](http://winavr.sourceforge.net/) on Windows. -You can edit *Makefile* and *config.h* to change compile options and pin configuration. +To compile firmware you need AVR GCC. You can edit *Makefile* and *config.h* to change compile options and pin configuration. $ git clone git://github.com/tmk/tmk_keyboard.git (or download source) $ cd m0110_usb @@ -71,64 +66,69 @@ Keymap You can change keymaps by editing *keymap.c*. ### M0110 & M0120 -#### *Default* - ,---------------------------------------------------------. ,---------------. - | `| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| -| =|Backs| |Ctl| -|Lft|Rgt| - |---------------------------------------------------------| |---------------| - |Tab | Q| W| E| R| T| Y| U| I| O| P| [| ]| \| | 7| 8| 9| Up| - |---------------------------------------------------------| |---------------| - |Fn0 | A| S| D| F| G| H| J| K| L| ;| '|Return| | 4| 5| 6| Dn| - |---------------------------------------------------------| |---------------| - |Shift | Z| X| C| V| B| N| M| ,| ,| /|Shift | | 1| 2| 3| | - `---------------------------------------------------------' |-----------|Ent| - |Ctl|Alt | Space |Gui |Ctl| | 0| .| | - `-----------------------------------------------' `---------------' -#### *HHKB/WASD Layer(WASD/IJKL)* - ,---------------------------------------------------------. ,---------------. - |Esc| F1| F2| F3| F4| F5| F6| F7| F8| F9|F10|F11|F12|Delet| |Nlk| -|Lft|Rgt| - |---------------------------------------------------------| |---------------| - |Caps |Hom| Up|PgU| | | |PgU| Up|Hom|Psc|Slk|Pau|Ins| | 7| 8| 9| Up| - |---------------------------------------------------------| |---------------| - |Fn0 |Lef|Dow|Rig| | | |Lef|Dow|Rig| | |Return| | 4| 5| 6| Dn| - |---------------------------------------------------------| |---------------| - |Shift |End| |PgD| | | |PgD| |End| |Shift | | 1| 2| 3| | - `---------------------------------------------------------' |-----------|Ent| - |Ctl|Alt | Space |Gui |Ctl| | 0| .| | - `-----------------------------------------------' `---------------' +#### *Default Layer* + ,---------------------------------------------------------. ,---------------. + | `| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| -| =|Backs| |Clr| -|Lft|Rgt| + |---------------------------------------------------------| |---------------| + |Tab | Q| W| E| R| T| Y| U| I| O| P| [| ]| \| | 7| 8| 9| Up| + |---------------------------------------------------------| |---------------| + |Caps | A| S| D| F| G| H| J| K| L| ;| '|Enter | | 4| 5| 6| Dn| + |---------------------------------------------------------| |---------------| + |Shift | Z| X| C| V| B| N| M| ,| ,| /|Shift | | 1| 2| 3| | + `---------------------------------------------------------' |-----------|Ent| + |Ctl|Gui | Space |Alt |Ctl| | 0| .| | + `-----------------------------------------------' `---------------' + +- `Space` and `Enter` also work as `Fn` layer switch key when holding down. + +#### *Function Layer(WASD/HHKB)* + ,---------------------------------------------------------. ,---------------. + |Esc| F1| F2| F3| F4| F5| F6| F7| F8| F9|F10|F11|F12|Delet| |Nlk| -|Lft|Rgt| + |---------------------------------------------------------| |---------------| + |Caps |Hom| Up|PgU| | | | |Psc|Slk|Pau|Up |Ins| \| | 7| 8| 9| Up| + |---------------------------------------------------------| |---------------| + |Caps |Lef|Dow|Rig| | | | |Hom|PgU|Lef|Rig|Enter | | 4| 5| 6| Dn| + |---------------------------------------------------------| |---------------| + |Shift |End| |PgD| | | | |End|PgD|Dow|Shift | | 1| 2| 3| | + `---------------------------------------------------------' |-----------|Ent| + |Ctl|Gui | Space |Alt |Ctl| | 0| .| | + `-----------------------------------------------' `---------------' + ### M0110A -#### *Default* +#### *Default Layer* ,---------------------------------------------------------. ,---------------. - | `| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| -| =|Backs| |Ctl| =| /| *| + | `| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| -| =|Backs| |Clr| =| /| *| |---------------------------------------------------------| |---------------| |Tab | Q| W| E| R| T| Y| U| I| O| P| [| ]| | | 7| 8| 9| -| |-----------------------------------------------------' | |---------------| - |Fn0 | A| S| D| F| G| H| J| K| L| ;| '|Return| | 4| 5| 6| +| + |Caps | A| S| D| F| G| H| J| K| L| ;| '|Enter | | 4| 5| 6| +| |---------------------------------------------------------| |---------------| |Shift | Z| X| C| V| B| N| M| ,| ,| /|Shft| Up| | 1| 2| 3| | |---------------------------------------------------------| |-----------|Ent| - |Alt |Gui | Space | \|Lft|Rgt| Dn| | 0| .| | + |Ctrl |Gui | Space | \|Lft|Rgt|Dwn| | 0| .| | `---------------------------------------------------------' `---------------' -#### *Cursor Layer(WASD/IJKL)* + +- `Space` and `Enter` also work as `Fn` layer switch key when holding down. +- `Backslash(\)` also works as `Alt` when holding down. + +#### *Function Layer(WASD/HHKB)* ,---------------------------------------------------------. ,---------------. |Esc| F1| F2| F3| F4| F5| F6| F7| F8| F9|F10|F11|F12|Delet| |Nlk| =| /| *| |---------------------------------------------------------| |---------------| - |Caps |Hom| Up|PgU| | | |PgU| Up|Hom|Psc|Slk|Pau| | | 7| 8| 9| -| + |Caps |Hom| Up|PgU| | | | |Psc|Slk|Pau|Up |Ins| | | 7| 8| 9| -| |-----------------------------------------------------' | |---------------| - |Fn0 |Lef|Dow|Rig| | | |Lef|Dow|Rig| | |Return| | 4| 5| 6| +| + |Caps |Lef|Dow|Rig| | | | |Hom|PgU|Lef|Rig|Enter | | 4| 5| 6| +| |---------------------------------------------------------| |---------------| - |Shift |End| |PgD| | | |PgD| |End| |Shif|PgU| | 1| 2| 3| | + |Shift |End| |PgD| | | | |End|PgD|Dow|Shif|PgU| | 1| 2| 3| | |---------------------------------------------------------| |-----------|Ent| - |Alt |Gui | Space |Ins|Hom|End|PgD| | 0| .| | + |Ctrl |Gui | Space | \|Hom|End|PgD| | 0| .| | `---------------------------------------------------------' `---------------' Debug ----- -You can use [PJRC HID listen](http://www.pjrc.com/teensy/hid_listen.html) to see debug output. - -The converter has some functions for debug, press `+H` simultaneously to get help. -These function is totally undocumented, tentative, inconsistent and buggy. +You can use [PJRC HID listen](http://www.pjrc.com/teensy/hid_listen.html) to see debug output. The converter has some functions for debug, press `+H` simultaneously to get help. -magickey: Shift+Option+Command(Shift+Alt+Gui or Shift+Alt+Control) +- Command: `Shift+Option+Command`(`Shift+Alt+Gui` or `Shift+Alt+Control`) diff --git a/converter/m0110_usb/config.h b/converter/m0110_usb/config.h index 2f63a3a490..801bc4ebfa 100644 --- a/converter/m0110_usb/config.h +++ b/converter/m0110_usb/config.h @@ -32,10 +32,6 @@ along with this program. If not, see . #define MATRIX_COLS 8 -/* legacy keymap support */ -#define USE_LEGACY_KEYMAP - - /* Mechanical locking support. Use KC_LCAP, KC_LNUM or KC_LSCR instead in keymap */ #define LOCKING_SUPPORT_ENABLE /* Locking resynchronize hack */ @@ -48,15 +44,19 @@ along with this program. If not, see . keyboard_report->mods == (MOD_BIT(KC_LSHIFT) | MOD_BIT(KC_LALT) | MOD_BIT(KC_LCTL)) \ ) +/* boot magic key */ +#define BOOTMAGIC_KEY_SALT KC_FN0 +#define BOOTMAGIC_KEY_CAPSLOCK_TO_CONTROL KC_LCAP + /* ports */ #define M0110_CLOCK_PORT PORTD #define M0110_CLOCK_PIN PIND #define M0110_CLOCK_DDR DDRD -#define M0110_CLOCK_BIT 0 +#define M0110_CLOCK_BIT 1 #define M0110_DATA_PORT PORTD #define M0110_DATA_PIN PIND #define M0110_DATA_DDR DDRD -#define M0110_DATA_BIT 1 +#define M0110_DATA_BIT 0 #endif diff --git a/converter/m0110_usb/doc/m0110.jpg b/converter/m0110_usb/doc/m0110.jpg deleted file mode 100644 index ef9a123abc..0000000000 Binary files a/converter/m0110_usb/doc/m0110.jpg and /dev/null differ diff --git a/converter/m0110_usb/doc/teensy.jpg b/converter/m0110_usb/doc/teensy.jpg deleted file mode 100644 index 96e93e7e24..0000000000 Binary files a/converter/m0110_usb/doc/teensy.jpg and /dev/null differ diff --git a/converter/m0110_usb/keymap.c b/converter/m0110_usb/keymap.c index 7a3bc35856..02c6ef9cd2 100644 --- a/converter/m0110_usb/keymap.c +++ b/converter/m0110_usb/keymap.c @@ -44,7 +44,7 @@ along with this program. If not, see . * |---------------------------------------------------------| |---------------| * |Tab | Q| W| E| R| T| Y| U| I| O| P| [| ]| | | 7| 8| 9| -| * |-----------------------------------------------------' | |---------------| - * |Caps | A| S| D| F| G| H| J| K| L| ;| '|Return| | 4| 5| 6| +| + * |Caps | A| S| D| F| G| H| J| K| L| ;| '|Enter | | 4| 5| 6| +| * |---------------------------------------------------------| |---------------| * |Shift | Z| X| C| V| B| N| M| ,| ,| /|Shft|Up | | 1| 2| 3| | * |---------------------------------------------------------' |-----------|Ent| @@ -57,7 +57,7 @@ along with this program. If not, see . * |---------------------------------------------------------| |---------------| * |Tab | Q| W| E| R| T| Y| U| I| O| P| [| ]| \| | 7| 8| 9| /| * |---------------------------------------------------------| |---------------| - * |Caps | A| S| D| F| G| H| J| K| L| ;| '|Return| | 4| 5| 6| ,| + * |Caps | A| S| D| F| G| H| J| K| L| ;| '|Enter | | 4| 5| 6| ,| * |---------------------------------------------------------| |---------------| * |Shift | Z| X| C| V| B| N| M| ,| ,| /|Shift | | 1| 2| 3| | * `---------------------------------------------------------' |-----------|Ent| @@ -77,7 +77,7 @@ along with this program. If not, see . * |---------------------------------------------------------| |---------------| * |Tab | Q| W| E| R| T| Y| U| I| O| P| [| ]| | | 7| 8| 9| -| * |-----------------------------------------------------' | |---------------| - * |Caps | A| S| D| F| G| H| J| K| L| ;| '|Return| | 4| 5| 6| +| + * |Caps | A| S| D| F| G| H| J| K| L| ;| '|Enter | | 4| 5| 6| +| * |---------------------------------------------------------| |---------------| * |Shift | Z| X| C| V| B| N| M| ,| ,| /|Shft|Up | | 1| 2| 3| | * |---------------------------------------------------------| |-----------|Ent| @@ -108,89 +108,79 @@ along with this program. If not, see . { KC_##K68, KC_NO, KC_NO, KC_NO, KC_NO, KC_##K6D, KC_NO, KC_NO }, \ } -#define KEYCODE(layer, row, col) (pgm_read_byte(&keymaps[(layer)][(row)][(col)])) - - -// Assign Fn key(0-7) to a layer to which switch with the Fn key pressed. -static const uint8_t PROGMEM fn_layer[] = { - 1, // Fn0 - 0, // Fn1 - 0, // Fn2 - 0, // Fn3 - 0, // Fn4 - 0, // Fn5 - 0, // Fn6 - 0 // Fn7 -}; - -// Assign Fn key(0-7) to a keycode sent when release Fn key without use of the layer. -// See layer.c for details. -static const uint8_t PROGMEM fn_keycode[] = { - KC_NO, // Fn0 - KC_NO, // Fn1 - KC_NO, // Fn2 - KC_NO, // Fn3 - KC_NO, // Fn4 - KC_NO, // Fn5 - KC_NO, // Fn6 - KC_NO // Fn7 -}; - -static const uint8_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = { +#ifdef KEYMAP_SECTION_ENABLE +const uint8_t keymaps[][MATRIX_ROWS][MATRIX_COLS] __attribute__ ((section (".keymap.keymaps"))) = { +#else +static const uint8_t keymaps[][MATRIX_ROWS][MATRIX_COLS] PROGMEM = { +#endif /* Default: * ,---------------------------------------------------------. ,---------------. - * | `| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| -| =|Backs| |Ctl| =| /| *| + * | `| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| -| =|Backs| |Clr| =| /| *| * |---------------------------------------------------------| |---------------| * |Tab | Q| W| E| R| T| Y| U| I| O| P| [| ]| | | 7| 8| 9| -| * |-----------------------------------------------------' | |---------------| - * |Fn0 | A| S| D| F| G| H| J| K| L| ;| '|Return| | 4| 5| 6| +| + * |Caps | A| S| D| F| G| H| J| K| L| ;| '|Enter | | 4| 5| 6| +| * |---------------------------------------------------------| |---------------| * |Shift | Z| X| C| V| B| N| M| ,| ,| /|Shft|Up | | 1| 2| 3| | * |---------------------------------------------------------| |-----------|Ent| - * |Ctl |Alt | Space |Gui| \|Lft|Rgt|Dn | | 0| .| | + * |Ctl |Gui | Space |Alt| \|Lft|Rgt|Dn | | 0| .| | * `---------------------------------------------------------' `---------------' */ KEYMAP( - GRV, 1, 2, 3, 4, 5, 6, 7, 8, 9, 0, MINS,EQL, BSPC, LCTL,EQL, PSLS,PAST, + GRV, 1, 2, 3, 4, 5, 6, 7, 8, 9, 0, MINS,EQL, BSPC, CLR, EQL, PSLS,PAST, TAB, Q, W, E, R, T, Y, U, I, O, P, LBRC,RBRC, P7, P8, P9, PMNS, - FN0, A, S, D, F, G, H, J, K, L, SCLN,QUOT, ENT, P4, P5, P6, PPLS, + LCAP,A, S, D, F, G, H, J, K, L, SCLN,QUOT, FN1, P4, P5, P6, PPLS, LSFT,Z, X, C, V, B, N, M, COMM,DOT, SLSH, UP, P1, P2, P3, PENT, - LCTL,LALT, SPC, LGUI,BSLS,LEFT,RGHT,DOWN, P0, PDOT + LCTL,LGUI, FN0, LALT,FN2, LEFT,RGHT,DOWN, P0, PDOT ), /* Cursor Layer(WASD, IJKL) * ,---------------------------------------------------------. ,---------------. * |Esc| F1| F2| F3| F4| F5| F6| F7| F8| F9|F10|F11|F12|Delet| |Nlk| =| /| *| * |---------------------------------------------------------| |---------------| - * |Caps |Hom| Up|PgU| | | |PgU| Up|Hom|Psc|Slk|Pau| | | 7| 8| 9| -| + * |Caps |Hom| Up|PgU| | | | |Psc|Slk|Pau|Up |Ins| | | 7| 8| 9| -| * |-----------------------------------------------------' | |---------------| - * |Fn0 |Lef|Dow|Rig| | | |Lef|Dow|Rig| | |Return| | 4| 5| 6| +| + * |Caps |Lef|Dow|Rig| | | | |Hom|PgU|Lef|Rig|Enter | | 4| 5| 6| +| * |---------------------------------------------------------| |---------------| - * |Shift |End| |PgD| | | |PgD| |End| |Shif|PgU| | 1| 2| 3| | + * |Shift |End| |PgD| | | | |End|PgD|Dow|Shif|PgU| | 1| 2| 3| | * |---------------------------------------------------------| |-----------|Ent| - * |Ctl |Alt | Space |Gui |Ins|Hom|End|PgD| | 0| .| | + * |Ctl |Gui | Space |Alt | \|Hom|End|PgD| | 0| .| | * `---------------------------------------------------------' `---------------' */ KEYMAP( ESC, F1, F2, F3, F4, F5, F6, F7, F8, F9, F10, F11, F12, DEL, NLCK,EQL, PSLS,PAST, - CAPS,HOME,UP, PGUP,NO, NO, NO, PGUP,UP, HOME,PSCR,SLCK,PAUS, P7, P8, P9, PMNS, - FN0, LEFT,DOWN,RGHT,NO, NO, NO, LEFT,DOWN,RGHT,NO, NO, ENT, P4, P5, P6, PPLS, - LSFT,END, NO, PGDN,NO, NO, NO, PGDN,NO, END, NO, PGUP, P1, P2, P3, PENT, - LCTL,LALT, SPC, LGUI,INS, HOME,END, PGDN, P0, PDOT + CAPS,HOME,UP, PGUP,NO, NO, NO, NO, PSCR,SLCK,PAUS,UP, INS, P7, P8, P9, PMNS, + LCAP,LEFT,DOWN,RGHT,NO, NO, NO, NO, HOME,PGUP,LEFT,RGHT, FN1, P4, P5, P6, PPLS, + LSFT,END, NO, PGDN,NO, NO, NO, NO, END, PGDN,DOWN, PGUP, P1, P2, P3, PENT, + LCTL,LGUI, FN0, LALT,FN2, HOME,END, PGDN, P0, PDOT ), }; -uint8_t keymap_get_keycode(uint8_t layer, uint8_t row, uint8_t col) -{ - return KEYCODE(layer, row, col); -} +/* + * Fn action definition + */ +#ifdef KEYMAP_SECTION_ENABLE +const uint16_t fn_actions[] __attribute__ ((section (".keymap.fn_actions"))) = { +#else +static const uint16_t fn_actions[] PROGMEM = { +#endif + [0] = ACTION_LAYER_TAP_KEY(1, KC_SPACE), // Layer switch with Tap key Space + [1] = ACTION_LAYER_TAP_KEY(1, KC_ENTER), // Layer switch with Tap key Enter + [2] = ACTION_MODS_TAP_KEY(MOD_LALT, KC_BSLS), // LALT with Tap key Backslash +}; + + -uint8_t keymap_fn_layer(uint8_t index) +/* translates key to keycode */ +uint8_t keymap_key_to_keycode(uint8_t layer, key_t key) { - return pgm_read_byte(&fn_layer[index]); + return pgm_read_byte(&keymaps[(layer)][(key.row)][(key.col)]); } -uint8_t keymap_fn_keycode(uint8_t index) +/* translates Fn index to action */ +action_t keymap_fn_to_action(uint8_t keycode) { - return pgm_read_byte(&fn_keycode[index]); + action_t action; + action.code = pgm_read_word(&fn_actions[FN_INDEX(keycode)]); + return action; } diff --git a/protocol/m0110.c b/protocol/m0110.c index 8bf7cfe4fe..9b53ec2cd6 100644 --- a/protocol/m0110.c +++ b/protocol/m0110.c @@ -91,10 +91,11 @@ uint8_t m0110_error = 0; void m0110_init(void) { - uint8_t data; idle(); _delay_ms(1000); +/* Not needed to initialize in fact. + uint8_t data; m0110_send(M0110_MODEL); data = m0110_recv(); print("m0110_init model: "); phex(data); print("\n"); @@ -102,6 +103,7 @@ void m0110_init(void) m0110_send(M0110_TEST); data = m0110_recv(); print("m0110_init test: "); phex(data); print("\n"); +*/ } uint8_t m0110_send(uint8_t data)