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Let's make it slightly less wide - move the MIDI connectors to the left side to make room, and put the rotary at the top instead where you won't stomp on it by mistake. Make the board a bit taller instead, and switch to the side-lit WS2812B-4020 LEDs at the bottom. Add a couple more, just in case: once you have one, the rest are basically "free". The through-hole components are now marked for thermal relief to make them easier to solder. And the eeprom is now gone for good, since I ended up just using a portion of the rp2354 flash to save scene state in the end. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
81 lines
3.0 KiB
C
81 lines
3.0 KiB
C
//
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// The unified board. Hardware/usb-stomp.
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//
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// One board instead of two: the rotary encoder *and* the MIDI jacks that
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// the split boards each had only one of, plus an expression jack that is
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// new here, plus three addressable LEDs where there was one PWM one.
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// First board built from design blocks rather than the daughtercard.
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//
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// It shares four GPIOs with the split map and nothing else, which is
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// what needing the ADC pins for the expression jack costs. Getting it
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// wrong is not subtle - see board.h.
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//
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// The Hardware/ project is still called usb-stomp, for a historical
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// reason that has stopped being interesting: every board has always had
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// a USB connector and a stomp switch, but on the older ones the USB was
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// an internal header for programming the MCU, and this was the one that
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// brought it out to the panel. The name records that and nothing else.
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//
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#define MIDI_HW 1
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//
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// No plain LED at all. There is one on the board, but it is across +5V
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// through a resistor - a power indicator, not something addressable.
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// The three WS2812Bs below are the only LEDs the firmware has, which is
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// why LED_GPIO is absent rather than zero: hardware.h keys the whole PWM
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// path off whether WS2812_GPIO exists.
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//
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#define ROTARY_A_GPIO 12
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#define ROTARY_B_GPIO 13
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#define ROTARY_SW_GPIO 14
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#define STOMP_GPIO 0
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//
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// Hardware MIDI out through an AHCT buffer at 5V, in through a TLP2310
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// optocoupler.
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//
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// Funcsel 2 rather than the 11 the split boards need: on 20/21 UART1
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// TX/RX *is* function 2, which is plain GPIO_FUNC_UART and wants no
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// special case at all. That was the point of moving to these pins.
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//
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#define MIDI_OUT 20
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#define MIDI_IN 21
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#define MIDI_FUNCSEL 2
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//
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// The expression jack. A TRS jack, and both signal contacts reach the
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// chip the same way:
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//
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// J103.T --- R105 1k --- GPIO27/ADC1 --- C107 22nF --- GND
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// J103.R --- R104 1k --- GPIO26/ADC0 --- C104 22nF --- GND
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// J103.S, J103.TN, J103.RN --- GND
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//
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// The 1k in series is what makes it safe to drive either pin as an
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// output: everything a guitarist can plug in here shorts one of them to
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// ground sooner or later, and 3.3mA is not a fault. A BAT54S on each
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// clamps to the rails.
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//
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// Both normalling contacts are grounded, so an *empty* jack reads as two
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// pins held at zero - the same thing a closed footswitch reads as. That
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// is a real ambiguity and not an oversight of the wiring; see exp.h.
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//
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// These are the two pins the split boards spend on hardware MIDI, which
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// is why the expression jack could not have existed on them.
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//
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#define EXP_TIP_GPIO 27
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#define EXP_RING_GPIO 26
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#define EXP_TIP_ADC 1
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#define EXP_RING_ADC 0
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//
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// The smart LEDs. Three WS2812B-2020 in a chain off one pin, driven
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// straight from 3.3V logic - modern parts take 0.55*VSS as a high, and
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// these do; older ones and clones want a level shifter.
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//
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// GPIO 25 is not a leftover: it is what this board wires them to, and
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// the knob test board independently arrived at the same pin.
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//
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#define WS2812_GPIO 25
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#define NR_LEDS 3
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