[nit.git] / lib / bcm2835 / bcm2835.nit

# This file is part of NIT ( http://www.nitlanguage.org ).
#
# Copyright 2013 Alexis Laferrière <alexis.laf@xymus.net>
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

# Services to control the bcm2835 chipset used in the Raspberry Pi
#
# Uses the C library by Mike McCauley available at http://www.airspayce.com/mikem/bcm2835/
#
# This module targets the model B revision 1, it could be tweaked for other versions.
module bcm2835

in "C Header" `{
        #include <bcm2835.h>
`}

redef class Object
        protected fun bcm2835_init: Bool `{ return bcm2835_init(); `}
        protected fun bcm2835_close `{ bcm2835_close(); `}
        protected fun bcm2835_debug=(v: Bool) `{ bcm2835_set_debug(v); `}
end

# A physical binary pin
interface Pin
        # Set the output of this pin
        fun write(high: Bool) is abstract
end

extern class RPiPin `{ RPiGPIOPin `}
        super Pin

        new p1_03 `{ return RPI_GPIO_P1_03; `}

        new p1_05 `{ return RPI_GPIO_P1_05; `}
        new p1_07 `{ return RPI_GPIO_P1_07; `}

        new p1_11 `{ return RPI_GPIO_P1_11; `}
        new p1_12 `{ return RPI_GPIO_P1_12; `}
        new p1_13 `{ return RPI_GPIO_P1_13; `}

        new p1_15 `{ return RPI_GPIO_P1_15; `}
        new p1_16 `{ return RPI_GPIO_P1_16; `}

        new p1_18 `{ return RPI_GPIO_P1_18; `}
        new p1_19 `{ return RPI_GPIO_P1_19; `}

        new p1_21 `{ return RPI_GPIO_P1_21; `}
        new p1_22 `{ return RPI_GPIO_P1_22; `}
        new p1_23 `{ return RPI_GPIO_P1_23; `}
        new p1_24 `{ return RPI_GPIO_P1_24; `}

        new p1_26 `{ return RPI_GPIO_P1_26; `}

        # Select mode: input, output or alts
        fun fsel=(mode: FunctionSelect) `{ bcm2835_gpio_fsel(self, mode); `}

        # Set output
        redef fun write(high) `{ bcm2835_gpio_write(self, high? HIGH: LOW); `}

        # Set pull up mode
        fun pud=(pud: PUDControl) `{ bcm2835_gpio_set_pud(self, pud); `}

        # Falling edge detect
        # Do not use on raspbian, it is bugged!
        fun fen `{ bcm2835_gpio_fen(self); `}
        fun clr_fen `{ bcm2835_gpio_clr_fen(self); `}

        # Raising edge detect
        # Do not use on raspbian, it is bugged!
        fun ren `{ bcm2835_gpio_ren(self); `}
        fun clr_ren `{ bcm2835_gpio_clr_ren(self); `}

        # High edge detect
        # Do not use on raspbian, it is bugged!
        fun hen `{ bcm2835_gpio_hen(self); `}
        fun clr_hen `{ bcm2835_gpio_clr_hen(self); `}

        # Low edge detect
        # Do not use on raspbian, it is bugged!
        fun len `{ bcm2835_gpio_len(self); `}
        fun clr_len `{ bcm2835_gpio_clr_len(self); `}

        fun set_eds `{ bcm2835_gpio_set_eds(self); `}
        fun eds: Bool `{ return bcm2835_gpio_eds(self); `}

        # Return input on pin, true for high and false for low
        fun lev: Bool `{ return bcm2835_gpio_lev(self); `}
end

extern class FunctionSelect `{ bcm2835FunctionSelect `}
        # Input function
        new inpt `{ return BCM2835_GPIO_FSEL_INPT; `}

        # Output function
        new outp `{ return BCM2835_GPIO_FSEL_OUTP; `}

        new alt0 `{ return BCM2835_GPIO_FSEL_ALT0; `}
        new alt1 `{ return BCM2835_GPIO_FSEL_ALT1; `}
        new alt2 `{ return BCM2835_GPIO_FSEL_ALT2; `}
        new alt3 `{ return BCM2835_GPIO_FSEL_ALT3; `}
        new alt4 `{ return BCM2835_GPIO_FSEL_ALT4; `}
        new alt5 `{ return BCM2835_GPIO_FSEL_ALT5; `}
        new mask `{ return BCM2835_GPIO_FSEL_MASK; `}
end

extern class PUDControl `{ bcm2835PUDControl `}
        new off `{ return BCM2835_GPIO_PUD_OFF; `}
        new down `{ return BCM2835_GPIO_PUD_DOWN; `}
        new up `{ return BCM2835_GPIO_PUD_UP; `}
end

redef universal Int
        fun bcm2835_delay `{ bcm2835_delay(self); `}
        fun bcm2835_delay_micros `{ bcm2835_delayMicroseconds(self); `}
end

class RotaryEncoder
        var pin_a: RPiPin
        var pin_b: RPiPin
        var old_a= false
        var old_b= false

        # returns '<', '>' or null accoring to rotation or lack thereof
        fun update: nullable Char
        do
                var new_a = pin_a.lev
                var new_b = pin_b.lev
                var res = null

                if new_a != old_a or new_b != old_b then
                        if not old_a and not old_b then
                                # everything was on
                                if not new_a and new_b then
                                        res = '<'
                                else if new_a and not new_b then
                                        res = '>'
                                end
                        else if old_a and old_b then
                                # everything was off
                                if not new_a and new_b then
                                        res = '>'
                                else if new_a and not new_b then
                                        res = '<'
                                end
                        end

                        old_a = new_a
                        old_b = new_b
                end

                return res
        end
end

# Hitachi HD44780 or similar 2-4 lines LCD displays
class HD44780
        var rs: RPiPin
        var en: RPiPin
        var d4: RPiPin
        var d5: RPiPin
        var d6: RPiPin
        var d7: RPiPin

        var ds = new Array[RPiPin]

        # commands
        fun flag_clear_display: Int do return 1
        fun flag_return_home: Int do return 2
        fun flag_entry_mode_set: Int do return 4
        fun flag_display_control: Int do return 8
        fun flag_cursor_shift: Int do return 16
        fun flag_function_set: Int do return 32
        fun flag_set_cgram_addr: Int do return 64
        fun flag_set_ggram_addr: Int do return 128

        # entry mode
        fun flag_entry_right: Int do return 0
        fun flag_entry_left: Int do return 2
        fun flag_entry_shift_increment: Int do return 1
        fun flag_entry_shift_decrement: Int do return 0

        # display flags
        fun flag_display_on: Int do return 4
        fun flag_display_off: Int do return 0
        fun flag_cursor_on: Int do return 2
        fun flag_cursor_off: Int do return 0
        fun flag_blink_on: Int do return 1
        fun flag_blink_off: Int do return 0

        # display/cursor shift
        fun flag_display_move: Int do return 8
        fun flag_cursor_move: Int do return 0
        fun flag_move_right: Int do return 4
        fun flag_move_left: Int do return 0

        # function set
        fun flag_8bit_mode: Int do return 16
        fun flag_4bit_mode: Int do return 0
        fun flag_2_lines: Int do return 8
        fun flag_1_line: Int do return 0
        fun flag_5x10_dots: Int do return 4
        fun flag_5x8_dots: Int do return 0

        # last text displayed
        private var last_text: nullable String = null

        fun function_set(bits, lines, dots_wide: Int)
        do
                var fs = flag_function_set
                if bits == 8 then
                        fs = fs | 16
                else if bits != 4 then abort

                if lines == 2 then
                        fs = fs | 8
                else if lines != 1 then abort

                if dots_wide == 10 then
                        fs = fs | 4
                else if dots_wide != 8 then abort

                write(true, fs)
        end

        fun display_control(on, cursor, blink: Bool)
        do
                var fs = flag_display_control

                fs |= if on then flag_display_on else flag_display_off

                fs |= if cursor then flag_cursor_on else flag_cursor_off

                fs |= if blink then flag_blink_on else flag_blink_off

                write(true, fs)
        end

        fun entry_mode(left, incr: Bool)
        do
                var fs = flag_entry_mode_set

                fs |= if left then flag_entry_left else flag_entry_right

                fs |= if incr then flag_entry_shift_increment else flag_entry_shift_decrement

                write(true, fs)
        end

        fun setup_alt
        do
                ds = [d4,d5,d6,d7]

                rs.fsel = new FunctionSelect.outp
                en.fsel = new FunctionSelect.outp
                d4.fsel = new FunctionSelect.outp
                d5.fsel = new FunctionSelect.outp
                d6.fsel = new FunctionSelect.outp
                d7.fsel = new FunctionSelect.outp

                rs.write(false)
                en.write(false)

                # wait 20ms for power up
                50.bcm2835_delay

                write_4bits(true,true,false,false)
                write_4_bits(3)

                5.bcm2835_delay

                write_4bits(true,true,false,false)
                write_4_bits(3)

                5.bcm2835_delay

                write_4bits(true,true,false,false)
                write_4_bits(3)

                200.bcm2835_delay_micros

                write_4bits(false,true,false,false)
                write_4_bits(2)

                # wait 5ms
                5.bcm2835_delay

                # set interface
                # 4bits, 2 lines
                function_set(4, 2, 8)

                # cursor
                # don't shift & hide
                display_control(true, true, true)

                # clear & home
                clear

                # set cursor move direction
                # move right
                write(true, 6)

                # turn on display
                write(true, 4)

                # set entry mode
                entry_mode(true, true)
        end

        fun setup
        do
                ds = [d4,d5,d6,d7]

                rs.fsel = new FunctionSelect.outp
                en.fsel = new FunctionSelect.outp
                d4.fsel = new FunctionSelect.outp
                d5.fsel = new FunctionSelect.outp
                d6.fsel = new FunctionSelect.outp
                d7.fsel = new FunctionSelect.outp

                rs.write(false)
                en.write(false)

                write(true, "33".to_hex) # init
                write(true, "32".to_hex) # init
                write(true, "28".to_hex) # 2 lines, 5x7
                write(true, "0C".to_hex) # hide cursor
                write(true, "06".to_hex) # cursor move right
                write(true, "04".to_hex) # turn on display
                write(true, "01".to_hex) # clear display
        end

        fun write_4_bits(v: Int)
        do
                var lb = once [1,2,4,8]
                for i in [0..4[ do
                        var b = lb[i]
                        var r = b & v != 0
                        var d = ds[i]
                        d.write(r)
                end
                pulse_enable
        end

        fun write_4bits(a,b,c,d:Bool)
        do
                d4.write(a)
                d5.write(b)
                d6.write(c)
                d7.write(d)
                pulse_enable
        end

        fun pulse_enable
        do
                en.write(false)
                1.bcm2835_delay_micros
                en.write(true)
                100.bcm2835_delay_micros
                en.write(false)
                1.bcm2835_delay_micros
        end

        fun write(is_cmd: Bool, cmd: Int)
        do
                en.write(false)
                rs.write(not is_cmd)

                # high byte
                var hb = once [16,32,64,128]
                for i in [0..4[ do
                        var b = hb[i]
                        var r = b & cmd != 0
                        var d = ds[i]
                        d.write(r)
                end

                pulse_enable

                if is_cmd then
                        # wait 5ms
                        5.bcm2835_delay
                else
                        # wait 200us
                        200.bcm2835_delay_micros
                end

                # low byte
                var lb = once [1,2,4,8]
                for i in [0..4[ do
                        var b = lb[i]
                        var r = b & cmd != 0
                        var d = ds[i]
                        d.write(r)
                end

                pulse_enable

                if is_cmd then
                        # wait 5ms
                        5.bcm2835_delay
                else
                        # wait 200us
                        200.bcm2835_delay_micros
                end
        end

        fun clear
        do
                write(true,1)
                2.bcm2835_delay
        end

        fun return_home
        do
                write(true,2)
                2.bcm2835_delay
        end

        fun text=(v: String)
        do
                # do not redraw the samething
                var last_text = last_text
                if last_text != null and last_text == v then return

                clear
                return_home
                var count = 0
                for c in v.chars do
                        if c == '\n' then
                                # FIXME, this should work
                                #write(true, "C0".to_hex)
                                # instead we use the following which may not be portable

                                for s in [count..40[ do write(false, ' '.code_point)
                                count = 0
                        else
                                write(false, c.code_point)
                                count += 1
                        end
                end

                self.last_text = v
        end
end

# Component for any kind of buttons or switches
class Switch
        var pin: RPiPin

        init (pin: RPiPin, pud: PUDControl)
        do
                self.pin = pin
                pin.fsel = new FunctionSelect.inpt
                pin.pud = pud
        end

        fun is_down: Bool do return pin.lev

        var last_down: nullable Bool = null

        # Returns true is state (is_down) changed since last call to `changed`
        fun changed: Bool
        do
                var now = is_down
                var last_down = last_down
                if last_down == null then
                        self.last_down = now
                        return false
                else if last_down != now then
                        self.last_down = now
                        return true
                else return false
        end
end

class StepperMotor
        var pins: Sequence[RPiPin]
        var delay: Int

        init (delay: Int, a, b, c, d: RPiPin)
        do
                pins = [a, b, c, d]
                self.delay = delay

                for p in pins do p.fsel = new FunctionSelect.outp
        end

        fun forward(steps: Int)
        do
                for s in [0..steps[ do
                        set(true, false, false, false)
                        delay.bcm2835_delay
                        set(true, true, false, false)
                        delay.bcm2835_delay
                        set(false, true, false, false)
                        delay.bcm2835_delay
                        set(false, true, true, false)
                        delay.bcm2835_delay
                        set(false, false, true, false)
                        delay.bcm2835_delay
                        set(false, false, true, true)
                        delay.bcm2835_delay
                        set(false, false, false, true)
                        delay.bcm2835_delay
                        set(true, false, false, true)
                        delay.bcm2835_delay
                end
        end

        fun backwards(steps: Int)
        do
                for s in [0..steps[ do
                        set(true, false, false, true)
                        delay.bcm2835_delay
                        set(false, false, false, true)
                        delay.bcm2835_delay
                        set(false, false, true, true)
                        delay.bcm2835_delay
                        set(false, false, true, false)
                        delay.bcm2835_delay
                        set(false, true, true, false)
                        delay.bcm2835_delay
                        set(false, true, false, false)
                        delay.bcm2835_delay
                        set(true, true, false, false)
                        delay.bcm2835_delay
                        set(true, false, false, false)
                        delay.bcm2835_delay
                end
        end

        fun release do set(false, false, false, false)

        protected fun set(a, b, c, d: Bool)
        do
                var bits = new Array[Bool].with_items(a, b, c, d)

                for i in [0..4[ do pins[i].write(bits[i])
        end
end

class Buzzer
        var pin: RPiPin

        fun buzz(delay: Float, times: Int)
        do
                assert times > 0
                assert delay > 0.0
                var delay_i = (delay*1000.0).to_i
                for i in [0..times[ do
                        pin.write(true)
                        delay_i.bcm2835_delay_micros
                        pin.write(false)
                        delay_i.bcm2835_delay_micros
                end
        end
end