add hhkb bluetooth functionality (rn42) (#2693)

* add hhkb bluetooth functionality (rn42) pretty much straight from tmk some minor changes to make things work * hhkb jp personal keymap * Revert "hhkb jp personal keymap" This reverts commit 886713d8bb.
2018-07-09 21:12:59 -04:00
parent a345458fa9
commit 5477bf39bf
14 changed files with 2040 additions and 0 deletions
--- a/keyboards/hhkb/config.h
+++ b/keyboards/hhkb/config.h
@ -54,6 +54,47 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
    keyboard_report->mods == (MOD_BIT(KC_LSHIFT) | MOD_BIT(KC_RSHIFT)) \
 )

+#ifdef HHKB_RN42_ENABLE
+// rn42 support -- acquired from the tmk repo. This is almost certainly not
+// integrated with qmk in the correct way.
+
+#define SUART_OUT_PORT  PORTD
+#define SUART_OUT_BIT   0
+#define SUART_IN_PIN    PIND
+#define SUART_IN_BIT    1
+
+#ifdef __AVR_ATmega32U4__
+    /* iom32u4.h has no definition of UCSR1D. copy from iom32u2.h */
+    #define UCSR1D _SFR_MEM8(0xCB)
+    #define RTSEN 0
+    #define CTSEN 1
+
+    #define SERIAL_UART_BAUD        115200
+    #define SERIAL_UART_DATA        UDR1
+    #define SERIAL_UART_UBRR        ((F_CPU/(16.0*SERIAL_UART_BAUD)-1+0.5))
+    #define SERIAL_UART_RXD_VECT    USART1_RX_vect
+    #define SERIAL_UART_TXD_READY   (UCSR1A&(1<<UDRE1))
+    #define SERIAL_UART_INIT()      do { \
+        UBRR1L = (uint8_t) SERIAL_UART_UBRR;       /* baud rate */ \
+        UBRR1H = ((uint16_t)SERIAL_UART_UBRR>>8);  /* baud rate */ \
+        UCSR1B |= (1<<RXCIE1) | (1<<RXEN1); /* RX interrupt, RX: enable */ \
+        UCSR1B |= (0<<TXCIE1) | (1<<TXEN1); /* TX interrupt, TX: enable */ \
+        UCSR1C |= (0<<UPM11) | (0<<UPM10);  /* parity: none(00), even(01), odd(11) */ \
+        UCSR1D |= (0<<RTSEN) | (0<<CTSEN);  /* RTS, CTS(no flow control by hardware) */ \
+        DDRD |= (1<<5); PORTD &= ~(1<<5);   /* RTS for flow control by firmware */ \
+        sei(); \
+    } while(0)
+    #define SERIAL_UART_RTS_LO()    do { PORTD &= ~(1<<5); } while (0)
+    #define SERIAL_UART_RTS_HI()    do { PORTD |=  (1<<5); } while (0)
+#else
+    #error "USART configuration is needed."
+#endif
+
+/* power control of key switch board */
+#define HHKB_POWER_SAVING
+
+#endif
+
 /*
 * Feature disable options
 *  These options are also useful to firmware size reduction.
--- a/keyboards/hhkb/rn42/MEMO.txt
+++ b/keyboards/hhkb/rn42/MEMO.txt
@ -0,0 +1,262 @@
+Memo of deveopment
+==================
+just memo, NOT WORTH READING
+
+2015/11/24
+JP Bluetooth:
+    RN-42 cannot send Japanese keys like; henkan, mu-henkan and kana, JPY and RO.
+    It seems HID usage more than 0x65 cannot be send with the module.
+        http://shiki.esrille.com/2014/07/bluetoothnisse.html
+
+
+Bug:
+- Factory Reset PIO4 doesn't work
+    - the reason is unclear - 12/08 NOT LOOK INTO ANY MORE
+    - WORKAROUND: use serial pins(3.3V, GND, RX and TX)
+        - SF,1 and R,1 to set factory defalult
+
+
+Todo:
+- LED cover and switch knob and new Slide Switch
+- RN42 auto configuration
+    - configure the module as HID device every time powering up
+    - this'll reduce work load of assembly
+
+- move rn42 to protocol directory when it becomes reusable stack
+
+- sendchar() in lufa.c no buffer
+    - no buffering. character lost can be caused.
+- LUFA sendchar should be buffered and serial_uart.c buffur size is too large(256).
+
+- BT operations
+    - disconnect
+    - new connection
+    - remove connection
+
+- sendchar() in lufa.c block loop   - DONE 11/29
+    - block loop when powered with AC adapter
+    - FrameNumber is not updated when adapter powered
+
+Improving:
+- ADC resolution
+    AVR120
+    AVR32138
+    - Enhancing ADC resolution by oversampling
+        AVR121  http://www.atmel.com/images/doc8003.pdf
+    - disable digital input buffer DIDR(7.8.6)
+
+Design:
+- suspend.h - DONE 11/26
+    - remove argument from suspend_power_down() for backward compatitibility
+- remove MCU dependent power saving code from core/keyboard - DONE 11/23
+    - it should be located in project matrix.c
+- HHKB matrix.c needs matrix_prev?
+    - is_modified() is obsolete now. really needs?
+- ADC: removing AREF capacitor C10
+    - seems to be better while usb powered
+    - still bad while battery powered
+    http://electronics.stackexchange.com/questions/105849/avcc-and-capacitor-using-adc
+- ADC: smaller resistors for voltage dividor
+    - 1K + 1K: not improved. - 11/27
+
+
+LUFA:
+USB connection check: state of USB deivce
+- USB_DeviceState:
+    USB_Deivce_State_t { Unattached, Powered, Default, Addressed, Configured*, Suspended* }
+    Unattached: unpluged
+    Powered:    pluged with power adapter
+    Default:    enumerate process bigin
+    Addressed:  addressed
+    Configured: enumerated
+    Suspended:  suspended
+
+- USB_IsInitialized: state of LUFA core setup
+    becomes true in USB_Init()  USBController_AVR8.c
+    becomes false in USB_Disable()  USBController_AVR8.c
+- USB_VBUS_GetStatus(): state of VBUS(power/connection)
+- USB_Disable() detaches, disables all interrupts, controller, PLL, regulater.
+
+- When connect to power adapter
+    - event happened: CW or CSW or C or DDC
+    - USB state: not configured
+
+- USB evnets
+    - USB connect: CSWRWRW
+    - USB connect but fail to enumeration: CWRWRWRWS
+    - USB disconnect: D
+    - Power adapter connect: CW, CSW, C
+    - Power adapter disconnect: D
+
+
+Power saving:
+- Pro2 current consumption
+    - active: 138.2mA(no device on Hub)
+    - suspended: 30.9mA(WakeUp enabled DIPSW6)
+    - suspended: 0mA->46.0mA(WakeUp disabled DIPSW6)
+- Pro current consumption
+    - active: 54.0mA
+    - suspended: 40.5mA(WakeUp enabled DIPSW6)
+    - suspended: 0.3mA(WakeUp disabled DIPSW6)
+
+- RN42 3.3V
+    - disconnected(Idle): 5mA (config mode)
+    - connected(Active):
+        SW,0000:  23-26mA
+        SW,0010:  27-29mA worse than 0000 for unknown reason
+        SW,0020:  17-19mA mouse NG
+        SW,0030:  13-16mA laggy mouse NG
+        SW,0050:  10-13mA laggy mouse NG
+
+- matrix power saving
+    - power saving while externally powered and not while unpluged
+- confirm suspend mode lufa.c: matrix_power_*, suspend_wakeup_condition
+- 8MHz clock
+- When not connected in a few minutes get into deep sleep to save battery life
+- CTS is needed for waking up from deep sleep? How deep sleep is activated?
+- firmware controlled 3.3V DC converter to switch on/off BT module
+- sleep MCU and BT module(keyboard is not used)
+- deep sleep MCU and BT module(keyboard is not used for long time)
+- deep sleep MCU and turn off BT module(keyboard is not used and not connected)
+- Battery ADC; switching, high resistance
+    - switching gnd end of divider with PF4
+    - high resistor 100K/1M?
+        capacitor   10nF
+        http://www.eevblog.com/forum/beginners/measuring-battery-voltage-without-consuming-current/
+- During USB suspend change clock source to internal RC from external Xtal(6.8)
+- FRZCLK: you can freeze clock for power saving. still WAKEUPI and VBUSTI interrupts are available while freezing.(21.7.3)
+- Suspend: Clear Suspend Bit, Freeze clock, disable PLL, MCU sleep(21.13)
+- Voltage reference(8.1.1)
+    - to reduce power consumption while power down mode
+- unset ADEN before sleep(24.7)
+
+
+
+
+
+
+
+Lipo
+----
+850mA lasts around 9 hours(07/28)
+
+Sparkfun Polymer Lithium Ion Battery 850mAh:
+https://www.sparkfun.com/products/341
+Lipo Cell spec:
+https://www.sparkfun.com/datasheets/Batteries/063048%20Li-polymer.pdf
+Protection spec:
+http://dlnmh9ip6v2uc.cloudfront.net/datasheets/Prototyping/BatteryProtection.pdf
+                                min     typical max
+    over-charge                 4.255   4.280   4.305
+    over-charge discover?       4.030   4.080   4.130
+    over-discharge              2.827   2.900   2.973
+    over-discharge discover     3.022   3.100   3.178
+
+ADC voltage monitor:    voltage divider 10K+10K(0.5)
+                        ADC=V*0.5/2.56*1024
+
+    V       ADC
+    ------------------
+    4.20    0x347(839)
+    3.10    0x26b(619)
+
+
+
+
+TROUBLE SHOOT
+-------------
+07/16   After fix of voltage dividor on GPIO6, had a trouble that it could not send a char to BT module, though could receive.
+        Found R8 had wrong 1K resistor and changed to 10K, after that it can send to the module again. Not sure how it had sent with the wrong 1K before.
+
+07/18   On Linux, had an USB related trouble; keyboard or console didn't work for some reason. Changing PID cured this problem. Very annoying, took very long time before resolved it.
+
+12/07   rn42_rts() read 1 every time. R12 broke in open mode(no coductive), idk why, too much heat with soldering? and PF1 pin was not soldered.
+        It resolved with resoldering PF1 and new resistor on R12.
+
+
+
+
+Done:
+- low battery alert(solid light) 09/04
+- *** Rev.E BT test *** - DONE
+    - with MCP73832, new Schottky, tantalum caps - DONE 12/07
+        * MCP73832 doesn't leak from Vcc pin when unpluged and battery powered
+            34mV vs 2.07V(MCP73831) at Vcc pin
+            MCP73832 doesn't need revese protection diode D5
+        * PMEG2010ER is very low VF while reverse current/voltage is high
+            VF=0.96 vs 1.98(RB160M-30TR)with Fluke 175
+            Anode of D11 is 680mV vs 20mV(RB160M-30TR)
+            780mV is still low < 1.4V VBUS plugin detection(21.11)
+                this doesn't cause false VBUS detect
+                and 780mV on MCP73832 Vcc pin is also no problem.
+            D5 can be removed.
+    - ADC divider switching - DONE 12/07
+        * Drain and Source of Q4 Pch was reversed wrongly on Rev.E.
+
+    - reverse current from Lipo charger - DONE 12/07
+        * MCP73832 has no recverse current from Vcc pin unlike MCP73831
+
+
+- Rev.F design - DONE
+    - current measure point - DONE 12/08
+    - change value of cap 68->47    - DONE 12/08
+    - PPTC land pattern: no solder jumper, use 0Ohm resistor instead - CANCEL 12/08
+    - Q4 Pch FET: wrong Drain and Source - DONE 12/08
+    - D5 can be removed.    - DONE 12/08
+
+
+
+- BT_INDICATOR LED turns on wrongly when touching line or pin.  -- pull-up enabled on PF6/GPIO2 08/30
+- Lipo charger configuration: fast charge time:  USB charger spec? -- used 2kohm
+- use LED of charger to alarm low battery. LED should be powered directly from Lipo? - cancel; powered from VUSB
+- Use RTS in serial_uart.c to resolve missing chars from help message of RN-42 - done
+- CTS/RTS lines are needed? just connect in loop back if no flow control is needed. - done
+- add IO pin to charger status CHRG; LED control(low) and detect charge status(input HiZ) 07.24
+- LINKED: add trace on PIO2 to PF6   07.24
+- Lipo voltage ADC sensing
+- Lipo charger MCP73831: needs capacitor 4.7uF *2
+- USB connection check - 07.01
+- BT on/off check: whether RX line is pulled up? - checking RTS 07.01
+- USB/BT switching  BT is on -> BT, BT is off -> USB - 07.01
+- Under voltage lock out UVLO for protection of Lipo - Lipo has discharge protection at 3.100V    07.01
+- Power saving: HHKB scan, BT radio control - 9h with 850mAh, this is enough   07.01
+- Power selector doesn't work; Q4 MOSFET leaks from Lipo to USB power line. -- use Schottky instead 07/04
+
+- wrongly suspended when powered from adapter without USB connection - DONE
+    - suspend event may occur when plug into adapter
+    - and never wake until conected to real USB line
+    - without debug print via USB no problem; CSW(wake just after suspend as real USB line)
+    - seems like USB print causes this problem after suspended
+
+- lose USB connection during power-down mode - DONE
+    - USB initialize code in main() causes this - WRONG
+    - Do not power-down during USB connection is active - DONE 11/11
+        (USB_DeviceState == USB_DEVICE_Configured) is used to check USB connection
+        matrix_power_down() matrix.c - 11/23
+
+- with Nexus5 keyboard and mouse are very laggy.
+    Not confirmed. 01/15
+
+- switch BT host connections    - CANCEL 01/15
+    - switch next connection
+        cannot switch connection with version 6.15 at least
+
+- When given power only from wall wart adapter  - DONE? not confirmed 01/15
+    - it sleeps. it should not sleep
+    - Configured state without USB connection?
+
+- timer is slow while power down - DONE 11/26
+    - time out interrupt is lost while power down?
+    - interrupt of watchdog timer compensates timer counter(avr/suspend.c)
+
+- repeated CHARGING/FULL_CHARGED    - No longer problem 01/15
+    - In LTC sharp pulses are observed.
+    - MCP has no pulse but still has a problem.
+    - needs more wait before read pin state? - NO
+
+- USB plug-in fails while BT        - No longer problem 01/15
+    - it ends in suspend state
+    - maybe, not responsive to host enumeration process due to power-down.
+    - matrix_power_down() only when state is unattached - 11/26
+        - need to observe a while
+
--- a/keyboards/hhkb/rn42/PowerSave.txt
+++ b/keyboards/hhkb/rn42/PowerSave.txt
@ -0,0 +1,88 @@
+Power Saving
+============
+
+
+MCU+HHKB Power Comsumption
+--------------------------
+Battery drive:
+    idle    18.9mA
+    active  35.8mA
+
+USB powered:
+    40.0mA
+    52mA    01/17
+
+Other keyboards:
+HHKB Pro    55mA
+HHKB Pro2   140mA
+HHKB Pro    42mA(Alt)
+HHKB Pro2   52mA(Alt BT controller USB mode)
+HHKB Pro2   88mA(Alt BT controller BT mode connected)
+HHKB Pro2   68mA(Alt BT controller BT mode config mode)
+Poker X     6mA
+Infinity    24mA(TMK)
+            65mA(kiibohd)
+
+
+HHKB key switch power control
+-----------------------------
+MOS FET Nch: BSS138 or IRLML6344T, either works and no apparent difference.
+Normally on(pull-up) or off(pull-down)? interms of power saving it prefers pull-down?
+
+Pull-down will be better for power saving, normally off.
+
+
+
+Used Timer
+----------
+
+8MHz clock
+----------
+1) 16MHz xtal with system prescaler div2: F_CPU=8MHz, F_USB=16MHz
+2) 8MHz xtal with div1: F_CPU=8MHz, F_USB=8MHz
+Hardware USART doesn't work at 115200bps with 8MHz(F_CPU).
+
+workaround:
+a) use Sotwre serial for communcation with RN-42
+b) reduce baud of RN-42 to lower rate;(factory default is 115200bps)
+10/03
+
+
+
+Slave mode
+----------
+Discovery/Inquire
+Connect/Page
+
+SI,0012
+SJ,0012
+InqWindw=0100
+PagWindw=0100
+
+
+Sniff mode
+----------
+0.625ms * <hex>
+SW,0320     Very sluggish. Type is not lost but very slow to register.
+SW,0160     Still sluggish. may transposed? can type but ...
+            Mouse point move intermittently
+SW,0020     feel a bit late like stumble(20ms)
+SW,0010     feel no latency(10ms)
+
+
+Deep sleep
+----------
+SW,8010
+
+
+TX power
+--------
+SY,fff4
+
+
+IO pins
+-------
+S%,1000         status led and connection control don't work
+                GPIO5: status LED
+                GPIO6: Connection control
+                GPIO2: linked status
--- a/keyboards/hhkb/rn42/RN42.txt
+++ b/keyboards/hhkb/rn42/RN42.txt
--- a/keyboards/hhkb/rn42/battery.c
+++ b/keyboards/hhkb/rn42/battery.c
@ -0,0 +1,130 @@
+#include <avr/io.h>
+#include <util/delay.h>
+#include "battery.h"
+
+
+/*
+ * Battery
+ */
+void battery_init(void)
+{
+    // blink
+    battery_led(LED_ON);  _delay_ms(100);
+    battery_led(LED_OFF); _delay_ms(100);
+    battery_led(LED_ON);  _delay_ms(100);
+    battery_led(LED_OFF); _delay_ms(100);
+    // LED indicates charger status
+    battery_led(LED_CHARGER);
+
+    // ADC setting for voltage monitor
+    // Ref:2.56V band-gap, Input:ADC0(PF0), Prescale:128(16MHz/128=125KHz)
+    ADMUX = (1<<REFS1) | (1<<REFS0);
+    ADCSRA = (1<<ADPS2) | (1<<ADPS1) | (1<<ADPS0);
+    // digital input buffer disable(24.9.5)
+    DIDR0 = (1<<ADC0D) | (1<<ADC4D) | (1<<ADC7D);
+    DIDR1 = (1<<AIN0D);
+    DIDR2 = (1<<ADC8D) | (1<<ADC9D) | (1<<ADC11D) | (1<<ADC12D) | (1<<ADC13D);
+
+    // ADC disable voltate divider(PF4)
+    DDRF  |=  (1<<4);
+    PORTF &= ~(1<<4);
+}
+
+// Indicator for battery
+void battery_led(battery_led_t val)
+{
+    if (val == LED_TOGGLE) {
+        // Toggle LED
+        DDRF  |=  (1<<5);
+        PINF  |=  (1<<5);
+    } else if (val == LED_ON) {
+        // On overriding charger status
+        DDRF  |=  (1<<5);
+        PORTF &= ~(1<<5);
+    } else if (val == LED_OFF) {
+        // Off overriding charger status
+        DDRF  |=  (1<<5);
+        PORTF |=  (1<<5);
+    } else {
+        // Display charger status
+        DDRF  &= ~(1<<5);
+        PORTF &= ~(1<<5);
+    }
+}
+
+bool battery_charging(void)
+{
+    if (!(USBSTA&(1<<VBUS))) return false;
+
+    // Charger Status:
+    //   MCP73831   MCP73832   LTC4054  Status
+    //   Hi-Z       Hi-Z       Hi-Z     Shutdown/No Battery
+    //   Low        Low        Low      Charging
+    //   Hi         Hi-Z       Hi-Z     Charged
+
+    // preserve last register status
+    uint8_t ddrf_prev  = DDRF;
+    uint8_t portf_prev = PORTF;
+
+    // Input with pullup
+    DDRF  &= ~(1<<5);
+    PORTF |=  (1<<5);
+    _delay_ms(1);
+    bool charging = PINF&(1<<5) ? false : true;
+
+    // restore last register status
+    DDRF  = (DDRF&~(1<<5))  | (ddrf_prev&(1<<5));
+    PORTF = (PORTF&~(1<<5)) | (portf_prev&(1<<5));
+
+    // TODO: With MCP73831 this can not get stable status when charging.
+    // LED is powered from PSEL line(USB or Lipo)
+    // due to weak low output of STAT pin?
+    // due to pull-up'd via resitor and LED?
+    return charging;
+}
+
+// Returns voltage in mV
+uint16_t battery_voltage(void)
+{
+    // ADC disable voltate divider(PF4)
+    DDRF  |=  (1<<4);
+    PORTF |=  (1<<4);
+
+    volatile uint16_t bat;
+    ADCSRA |= (1<<ADEN);
+    _delay_ms(1);   // wait for charging S/H capacitance
+
+    ADCSRA |= (1<<ADSC);
+    while (ADCSRA & (1<<ADSC)) ;
+    bat = ADC;
+
+    ADCSRA &= ~(1<<ADEN);
+
+    // ADC disable voltate divider(PF4)
+    DDRF  |=  (1<<4);
+    PORTF &= ~(1<<4);
+
+    return (bat - BATTERY_ADC_OFFSET) * BATTERY_ADC_RESOLUTION;
+}
+
+static bool low_voltage(void) {
+    static bool low = false;
+    uint16_t v = battery_voltage();
+    if (v < BATTERY_VOLTAGE_LOW_LIMIT) {
+        low = true;
+    } else if (v > BATTERY_VOLTAGE_LOW_RECOVERY) {
+        low = false;
+    }
+    return low;
+}
+
+battery_status_t battery_status(void)
+{
+    if (USBSTA&(1<<VBUS)) {
+        /* powered */
+        return battery_charging() ? CHARGING : FULL_CHARGED;
+    } else {
+        /* not powered */
+        return low_voltage() ? LOW_VOLTAGE : DISCHARGING;
+    }
+}
--- a/keyboards/hhkb/rn42/battery.h
+++ b/keyboards/hhkb/rn42/battery.h
@ -0,0 +1,35 @@
+#ifndef POWER_H
+#define POWER_H
+
+#include <stdint.h>
+#include <stdbool.h>
+
+typedef enum {
+    FULL_CHARGED,
+    CHARGING,
+    DISCHARGING,
+    LOW_VOLTAGE,
+    UNKNOWN,
+} battery_status_t;
+
+typedef enum {
+    LED_CHARGER = 0,
+    LED_ON,
+    LED_OFF,
+    LED_TOGGLE,
+} battery_led_t;
+
+/* Battery API */
+void battery_init(void);
+void battery_led(battery_led_t val);
+bool battery_charging(void);
+uint16_t battery_voltage(void);
+battery_status_t battery_status(void);
+
+#define BATTERY_VOLTAGE_LOW_LIMIT       3500
+#define BATTERY_VOLTAGE_LOW_RECOVERY    3700
+// ADC offset:16, resolution:5mV
+#define BATTERY_ADC_OFFSET              16
+#define BATTERY_ADC_RESOLUTION          5
+
+#endif
--- a/keyboards/hhkb/rn42/main.c
+++ b/keyboards/hhkb/rn42/main.c
@ -0,0 +1,106 @@
+#include <avr/io.h>
+#include <avr/power.h>
+#include <avr/wdt.h>
+#include "lufa.h"
+#include "print.h"
+#include "sendchar.h"
+#include "rn42.h"
+#include "rn42_task.h"
+#include "serial.h"
+#include "keyboard.h"
+#include "keycode.h"
+#include "action.h"
+#include "action_util.h"
+#include "wait.h"
+#include "suart.h"
+#include "suspend.h"
+#include "matrix.h"
+
+static int8_t sendchar_func(uint8_t c)
+{
+    xmit(c);        // SUART
+    sendchar(c);    // LUFA
+    return 0;
+}
+
+static void SetupHardware(void)
+{
+    /* Disable watchdog if enabled by bootloader/fuses */
+    MCUSR &= ~(1 << WDRF);
+    wdt_disable();
+
+    /* Disable clock division */
+    clock_prescale_set(clock_div_1);
+
+    // Leonardo needs. Without this USB device is not recognized.
+    USB_Disable();
+
+    USB_Init();
+
+    // for Console_Task
+    USB_Device_EnableSOFEvents();
+    print_set_sendchar(sendchar_func);
+
+    // SUART PD0:output, PD1:input
+    DDRD |= (1<<0);
+    PORTD |= (1<<0);
+    DDRD &= ~(1<<1);
+    PORTD |= (1<<1);
+}
+
+int main(void)  __attribute__ ((weak));
+int main(void)
+{
+    SetupHardware();
+    sei();
+
+    /* wait for USB startup to get ready for debug output */
+    uint8_t timeout = 255;  // timeout when USB is not available(Bluetooth)
+    while (timeout-- && USB_DeviceState != DEVICE_STATE_Configured) {
+        wait_ms(4);
+#if defined(INTERRUPT_CONTROL_ENDPOINT)
+        ;
+#else
+        USB_USBTask();
+#endif
+    }
+    print("\nUSB init\n");
+
+    rn42_init();
+    rn42_task_init();
+    print("RN-42 init\n");
+
+    /* init modules */
+    keyboard_init();
+
+#ifdef SLEEP_LED_ENABLE
+    sleep_led_init();
+#endif
+
+    print("Keyboard start\n");
+    while (1) {
+        while (rn42_rts() && // RN42 is off
+                USB_DeviceState == DEVICE_STATE_Suspended) {
+            print("[s]");
+            matrix_power_down();
+            suspend_power_down();
+            suspend_power_down();
+            suspend_power_down();
+            suspend_power_down();
+            suspend_power_down();
+            suspend_power_down();
+            suspend_power_down();
+            if (USB_Device_RemoteWakeupEnabled && suspend_wakeup_condition()) {
+                    USB_Device_SendRemoteWakeup();
+            }
+        }
+
+        keyboard_task();
+
+#if !defined(INTERRUPT_CONTROL_ENDPOINT)
+        USB_USBTask();
+#endif
+
+        rn42_task();
+    }
+}
--- a/keyboards/hhkb/rn42/rn42.c
+++ b/keyboards/hhkb/rn42/rn42.c
@ -0,0 +1,265 @@
+#include <avr/io.h>
+#include "host.h"
+#include "host_driver.h"
+#include "serial.h"
+#include "rn42.h"
+#include "print.h"
+#include "timer.h"
+#include "wait.h"
+
+
+/* Host driver */
+static uint8_t keyboard_leds(void);
+static void send_keyboard(report_keyboard_t *report);
+static void send_mouse(report_mouse_t *report);
+static void send_system(uint16_t data);
+static void send_consumer(uint16_t data);
+
+host_driver_t rn42_driver = {
+    keyboard_leds,
+    send_keyboard,
+    send_mouse,
+    send_system,
+    send_consumer
+};
+
+
+void rn42_init(void)
+{
+    // JTAG disable for PORT F. write JTD bit twice within four cycles.
+    MCUCR |= (1<<JTD);
+    MCUCR |= (1<<JTD);
+
+    // PF7: BT connection control(high: connect, low: disconnect)
+    rn42_autoconnect();
+
+    // PF6: linked(input without pull-up)
+    DDRF  &= ~(1<<6);
+    PORTF |=  (1<<6);
+
+    // PF1: RTS(low: allowed to send, high: not allowed)
+    DDRF &= ~(1<<1);
+    PORTF &= ~(1<<1);
+
+    // PD5: CTS(low: allow to send, high:not allow)
+    DDRD |= (1<<5);
+    PORTD &= ~(1<<5);
+
+    serial_init();
+}
+
+int16_t rn42_getc(void)
+{
+    return serial_recv2();
+}
+
+const char *rn42_gets(uint16_t timeout)
+{
+    static char s[24];
+    uint16_t t = timer_read();
+    uint8_t i = 0;
+    int16_t c;
+    while (i < 23 && timer_elapsed(t) < timeout) {
+        if ((c = rn42_getc()) != -1) {
+            if ((char)c == '\r') continue;
+            if ((char)c == '\n') break;
+            s[i++] = c;
+        }
+    }
+    s[i] = '\0';
+    return s;
+}
+
+void rn42_putc(uint8_t c)
+{
+    serial_send(c);
+}
+
+void rn42_puts(char *s)
+{
+    while (*s)
+	serial_send(*s++);
+}
+
+bool rn42_autoconnecting(void)
+{
+    // GPIO6 for control connection(high: auto connect, low: disconnect)
+    // Note that this needs config: SM,4(Auto-Connect DTR Mode)
+    return (PORTF & (1<<7) ? true : false);
+}
+
+void rn42_autoconnect(void)
+{
+    // hi to auto connect
+    DDRF |= (1<<7);
+    PORTF |= (1<<7);
+}
+
+void rn42_disconnect(void)
+{
+    // low to disconnect
+    DDRF |= (1<<7);
+    PORTF &= ~(1<<7);
+}
+
+bool rn42_rts(void)
+{
+    // low when RN-42 is powered and ready to receive
+    return PINF&(1<<1);
+}
+
+void rn42_cts_hi(void)
+{
+    // not allow to send
+    PORTD |= (1<<5);
+}
+
+void rn42_cts_lo(void)
+{
+    // allow to send
+    PORTD &= ~(1<<5);
+}
+
+bool rn42_linked(void)
+{
+    // RN-42 GPIO2
+    //   Hi-Z:  Not powered
+    //   High:  Linked
+    //   Low:   Connecting
+    return PINF&(1<<6);
+}
+
+
+static uint8_t leds = 0;
+static uint8_t keyboard_leds(void) { return leds; }
+void rn42_set_leds(uint8_t l) { leds = l; }
+
+
+void rn42_send_str(const char *str)
+{
+    uint8_t c;
+    while ((c = pgm_read_byte(str++)))
+        rn42_putc(c);
+}
+
+const char *rn42_send_command(const char *cmd)
+{
+    static const char *s;
+    rn42_send_str(cmd);
+    wait_ms(500);
+    s = rn42_gets(100);
+    xprintf("%s\r\n", s);
+    rn42_print_response();
+    return s;
+}
+
+void rn42_print_response(void)
+{
+    int16_t c;
+    while ((c = rn42_getc()) != -1) {
+        xprintf("%c", c);
+    }
+}
+
+
+static void send_keyboard(report_keyboard_t *report)
+{
+    // wake from deep sleep
+/*
+    PORTD |= (1<<5);    // high
+    wait_ms(5);
+    PORTD &= ~(1<<5);   // low
+*/
+
+    serial_send(0xFD);  // Raw report mode
+    serial_send(9);     // length
+    serial_send(1);     // descriptor type
+    serial_send(report->mods);
+    serial_send(0x00);
+    serial_send(report->keys[0]);
+    serial_send(report->keys[1]);
+    serial_send(report->keys[2]);
+    serial_send(report->keys[3]);
+    serial_send(report->keys[4]);
+    serial_send(report->keys[5]);
+}
+
+static void send_mouse(report_mouse_t *report)
+{
+    // wake from deep sleep
+/*
+    PORTD |= (1<<5);    // high
+    wait_ms(5);
+    PORTD &= ~(1<<5);   // low
+*/
+
+    serial_send(0xFD);  // Raw report mode
+    serial_send(5);     // length
+    serial_send(2);     // descriptor type
+    serial_send(report->buttons);
+    serial_send(report->x);
+    serial_send(report->y);
+    serial_send(report->v);
+}
+
+static void send_system(uint16_t data)
+{
+    // Table 5-6 of RN-BT-DATA-UB
+    // 81,82,83 scan codes can be used?
+}
+
+
+static uint16_t usage2bits(uint16_t usage)
+{
+    switch (usage) {
+        case AC_HOME:                 return 0x01;
+        case AL_EMAIL:                return 0x02;
+        case AC_SEARCH:               return 0x04;
+        //case AL_KBD_LAYOUT:         return 0x08;  // Apple virtual keybaord toggle
+        case AUDIO_VOL_UP:            return 0x10;
+        case AUDIO_VOL_DOWN:          return 0x20;
+        case AUDIO_MUTE:              return 0x40;
+        case TRANSPORT_PLAY_PAUSE:    return 0x80;
+        case TRANSPORT_NEXT_TRACK:    return 0x100;
+        case TRANSPORT_PREV_TRACK:    return 0x200;
+        case TRANSPORT_STOP:          return 0x400;
+        case TRANSPORT_STOP_EJECT:    return 0x800;
+        case TRANSPORT_FAST_FORWARD:  return 0x1000;
+        case TRANSPORT_REWIND:        return 0x2000;
+        //case return 0x4000;   // Stop/eject
+        //case return 0x8000;   // Internet browser
+    };
+    return 0;
+}
+
+static void send_consumer(uint16_t data)
+{
+    uint16_t bits = usage2bits(data);
+    serial_send(0xFD);  // Raw report mode
+    serial_send(3);     // length
+    serial_send(3);     // descriptor type
+    serial_send(bits&0xFF);
+    serial_send((bits>>8)&0xFF);
+}
+
+
+/* Null driver for config_mode */
+static uint8_t config_keyboard_leds(void);
+static void config_send_keyboard(report_keyboard_t *report);
+static void config_send_mouse(report_mouse_t *report);
+static void config_send_system(uint16_t data);
+static void config_send_consumer(uint16_t data);
+
+host_driver_t rn42_config_driver = {
+    config_keyboard_leds,
+    config_send_keyboard,
+    config_send_mouse,
+    config_send_system,
+    config_send_consumer
+};
+
+static uint8_t config_keyboard_leds(void) { return leds; }
+static void config_send_keyboard(report_keyboard_t *report) {}
+static void config_send_mouse(report_mouse_t *report) {}
+static void config_send_system(uint16_t data) {}
+static void config_send_consumer(uint16_t data) {}
--- a/keyboards/hhkb/rn42/rn42.h
+++ b/keyboards/hhkb/rn42/rn42.h
@ -0,0 +1,30 @@
+#ifndef RN42_H
+#define RN42_H
+
+#include <stdbool.h>
+#include "host_driver.h"
+
+host_driver_t rn42_driver;
+host_driver_t rn42_config_driver;
+
+void rn42_init(void);
+int16_t rn42_getc(void);
+const char *rn42_gets(uint16_t timeout);
+void rn42_putc(uint8_t c);
+void rn42_puts(char *s);
+bool rn42_autoconnecting(void);
+void rn42_autoconnect(void);
+void rn42_disconnect(void);
+bool rn42_rts(void);
+void rn42_cts_hi(void);
+void rn42_cts_lo(void);
+bool rn42_linked(void);
+void rn42_set_leds(uint8_t l);
+
+const char *rn42_send_command(const char *cmd);
+void rn42_send_str(const char *str);
+void rn42_print_response(void);
+#define SEND_STR(str)       rn42_send_str(PSTR(str))
+#define SEND_COMMAND(cmd)   rn42_send_command(PSTR(cmd))
+
+#endif
--- a/keyboards/hhkb/rn42/rn42_task.c
+++ b/keyboards/hhkb/rn42/rn42_task.c
--- a/keyboards/hhkb/rn42/rn42_task.h
+++ b/keyboards/hhkb/rn42/rn42_task.h
@ -0,0 +1,14 @@
+#ifndef RN42_TASK_H
+#define RN42_TASK_H
+
+#include <stdbool.h>
+#include "rn42.h"
+
+#ifdef NKRO_ENABLE
+bool rn42_nkro_last;
+#endif
+
+void rn42_task_init(void);
+void rn42_task(void);
+
+#endif
--- a/keyboards/hhkb/rn42/suart.S
+++ b/keyboards/hhkb/rn42/suart.S
@ -0,0 +1,156 @@
+;---------------------------------------------------------------------------;
+; Software implemented UART module                                          ;
+; (C)ChaN, 2005 (http://elm-chan.org/)                                      ;
+;---------------------------------------------------------------------------;
+; Bit rate settings:
+;
+;            1MHz  2MHz  4MHz  6MHz  8MHz  10MHz  12MHz  16MHz  20MHz
+;   2.4kbps   138     -     -     -     -      -      -      -      -
+;   4.8kbps    68   138     -     -     -      -      -      -      -
+;   9.6kbps    33    68   138   208     -      -      -      -      -
+;  19.2kbps     -    33    68   102   138    173    208      -      -
+;  38.4kbps     -     -    33    50    68     85    102    138    172
+;  57.6kbps     -     -    21    33    44     56     68     91    114
+; 115.2kbps     -     -     -     -    21     27     33     44     56
+
+.nolist
+#include <avr/io.h>
+.list
+
+#define	BPS	44 	/* Bit delay. (see above table) */
+#define	BIDIR	0	/* 0:Separated Tx/Rx, 1:Shared Tx/Rx */
+
+#define	OUT_1		sbi _SFR_IO_ADDR(SUART_OUT_PORT), SUART_OUT_BIT	/* Output 1 */
+#define	OUT_0		cbi _SFR_IO_ADDR(SUART_OUT_PORT), SUART_OUT_BIT	/* Output 0 */
+#define	SKIP_IN_1	sbis _SFR_IO_ADDR(SUART_IN_PIN), SUART_IN_BIT	/* Skip if 1 */
+#define	SKIP_IN_0	sbic _SFR_IO_ADDR(SUART_IN_PIN), SUART_IN_BIT	/* Skip if 0 */
+
+
+
+#ifdef SPM_PAGESIZE
+.macro	_LPMI	reg
+	lpm	\reg, Z+
+.endm
+.macro	_MOVW	dh,dl, sh,sl
+	movw	\dl, \sl
+.endm
+#else
+.macro	_LPMI	reg
+	lpm
+	mov	\reg, r0
+	adiw	ZL, 1
+.endm
+.macro	_MOVW	dh,dl, sh,sl
+	mov	\dl, \sl
+	mov	\dh, \sh
+.endm
+#endif
+
+
+
+;---------------------------------------------------------------------------;
+; Transmit a byte in serial format of N81
+;
+;Prototype: void xmit (uint8_t data);
+;Size: 16 words
+
+.global xmit
+.func xmit
+xmit:
+#if BIDIR
+	ldi	r23, BPS-1	;Pre-idle time for bidirectional data line
+5:	dec	r23     	;
+	brne	5b		;/
+#endif
+	in	r0, _SFR_IO_ADDR(SREG)	;Save flags
+
+	com	r24		;C = start bit
+	ldi	r25, 10		;Bit counter
+	cli			;Start critical section
+
+1:	ldi	r23, BPS-1	;----- Bit transferring loop
+2:	dec	r23     	;Wait for a bit time
+	brne	2b		;/
+	brcs	3f		;MISO = bit to be sent
+	OUT_1			;
+3:	brcc	4f		;
+	OUT_0			;/
+4:	lsr	r24     	;Get next bit into C
+	dec	r25     	;All bits sent?
+	brne	1b	     	;  no, coutinue
+
+	out	_SFR_IO_ADDR(SREG), r0	;End of critical section
+	ret
+.endfunc
+
+
+
+;---------------------------------------------------------------------------;
+; Receive a byte
+;
+;Prototype: uint8_t rcvr (void);
+;Size: 19 words
+
+.global rcvr
+.func rcvr
+rcvr:
+	in	r0, _SFR_IO_ADDR(SREG)	;Save flags
+
+	ldi	r24, 0x80	;Receiving shift reg
+	cli			;Start critical section
+
+1:	SKIP_IN_1		;Wait for idle
+	rjmp	1b
+2:	SKIP_IN_0		;Wait for start bit
+	rjmp	2b
+	ldi	r25, BPS/2	;Wait for half bit time
+3:	dec	r25
+	brne	3b
+
+4:	ldi	r25, BPS	;----- Bit receiving loop
+5:	dec	r25     	;Wait for a bit time
+	brne	5b		;/
+	lsr	r24     	;Next bit
+	SKIP_IN_0		;Get a data bit into r24.7
+	ori	r24, 0x80
+	brcc	4b	     	;All bits received?  no, continue
+
+	out	_SFR_IO_ADDR(SREG), r0	;End of critical section
+	ret
+.endfunc
+
+
+; Not wait for start bit. This should be called after detecting start bit.
+.global recv
+.func recv
+recv:
+	in	r0, _SFR_IO_ADDR(SREG)	;Save flags
+
+	ldi	r24, 0x80	;Receiving shift reg
+	cli			;Start critical section
+
+;1:	SKIP_IN_1		;Wait for idle
+;	rjmp	1b
+;2:	SKIP_IN_0		;Wait for start bit
+;	rjmp	2b
+	ldi	r25, BPS/2	;Wait for half bit time
+3:	dec	r25
+	brne	3b
+
+4:	ldi	r25, BPS	;----- Bit receiving loop
+5:	dec	r25     	;Wait for a bit time
+	brne	5b		;/
+	lsr	r24     	;Next bit
+	SKIP_IN_0		;Get a data bit into r24.7
+	ori	r24, 0x80
+	brcc	4b	     	;All bits received?  no, continue
+
+	ldi	r25, BPS/2	;Wait for half bit time
+6:	dec	r25
+	brne	6b
+7:	SKIP_IN_1		;Wait for stop bit
+	rjmp	7b
+
+	out	_SFR_IO_ADDR(SREG), r0	;End of critical section
+	ret
+.endfunc
--- a/keyboards/hhkb/rn42/suart.h
+++ b/keyboards/hhkb/rn42/suart.h
@ -0,0 +1,8 @@
+#ifndef SUART
+#define SUART
+
+void xmit(uint8_t);
+uint8_t rcvr(void);
+uint8_t recv(void);
+
+#endif	/* SUART */
--- a/keyboards/hhkb/rules.mk
+++ b/keyboards/hhkb/rules.mk
@ -72,6 +72,36 @@ CUSTOM_MATRIX = yes    # Custom matrix file for the HHKB
 # UNICODE_ENABLE = yes    # Unicode
 # BLUETOOTH_ENABLE = yes  # Enable Bluetooth with the Adafruit EZ-Key HID

+
+# HHKB_RN42_ENABLE = yes  # Enable support for hasu's BT alt controller -- code borrowed from tmk source tree.
+
+# Either uncomment the HHKB_RN42_ENABLE line above, or run make enabling the
+# feature. Be sure to clean any existing build before trying to enable rn42
+# support. For example:
+#
+# make hhkb-keymap-clean
+# make hhkb-keymap-dfu HHKB_RN42_ENABLE=yes
+
+ifeq ($(strip $(HHKB_RN42_ENABLE)), yes)
+
+OPT_DEFS += -DHHKB_RN42_ENABLE
+
+# Support for the RN42 Bluetooth module. This is the BT module in Hasu's BT
+# HHKB Alt controller.
+RN42_DIR = rn42
+
+SRC +=  serial_uart.c \
+	rn42/suart.S \
+	rn42/rn42.c \
+	rn42/rn42_task.c \
+	rn42/battery.c \
+	rn42/main.c
+
+VPATH += $(RN42_DIR)
+
+endif
+
+
 # debug-on: EXTRAFLAGS += -DDEBUG -DDEBUG_ACTION
 # debug-on: all