Sensor Watch Simulator (#35)

* Put something on screen

* Use the 32bit watch_date_time repr to pass from JS

* Implement periodic callbacks

* Clear display on enabling

* Hook up watch_set_led_color() to SVG (green-only)

* Make debug output full-width

* Remove default Emscripten canvas

* Implement sleep and button clicks

* Fix time zone conversion bug in beats-time app

* Clean up warnings

* Fix pin levels

* Set time zone to browser value (if available)

* Add basic backup data saving

* Silence format specifier warnings in both targets

* Remove unnecessary, copied files

* Use RTC pointer to clear callbacks (if available)

* Use preprocessor define to avoid hardcoding MOVEMENT_NUM_FACES

* Change each face to const preprocessor definition

* Remove Intl.DateTimeFormat usage

* Update shell.html title, header

* Add touch start/end event handlers on SVG buttons

* Update shell.html

* Update folder structure (shared, simulator, hardware under watch-library)

* Tease out shared components from watch_slcd

* Clean up simulator watch_slcd.c inline JS calls

* Fix missing newlines at end of file

* Add simulator warnings (except format, unused-paremter)

* Implement remaining watch_rtc functions

* Fix button bug on mouse down then drag out

* Implement remaining watch_slcd functions

* Link keyboard events to buttons (for keys A, L, M)

* Rewrite event handling (mouse, touch, keyboard) in C

* Set explicit text UTF-8 charset in shell.html

* Address PR comments

* Remove unused directories from include paths

1 files changed, 179 insertions, 0 deletions

diff --git a/watch-library/hardware/watch/watch_adc.c b/watch-library/hardware/watch/watch_adc.c
new file mode 100644
index 00000000..5ba7abdf
--- /dev/null
+++ b/watch-library/hardware/watch/watch_adc.c
@@ -0,0 +1,179 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2020 Joey Castillo
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#include "watch_adc.h"
+
+static void _watch_sync_adc(void) {
+    while (ADC->SYNCBUSY.reg);
+}
+
+static uint16_t _watch_get_analog_value(uint16_t channel) {
+    if (ADC->INPUTCTRL.bit.MUXPOS != channel) {
+        ADC->INPUTCTRL.bit.MUXPOS = channel;
+        _watch_sync_adc();
+    }
+
+    ADC->SWTRIG.bit.START = 1;
+    while (!ADC->INTFLAG.bit.RESRDY);
+
+    return ADC->RESULT.reg;
+}
+
+void watch_enable_adc(void) {
+    MCLK->APBCMASK.reg |= MCLK_APBCMASK_ADC;
+    GCLK->PCHCTRL[ADC_GCLK_ID].reg = GCLK_PCHCTRL_GEN_GCLK0 | GCLK_PCHCTRL_CHEN;
+
+    uint16_t calib_reg = 0;
+    calib_reg = ADC_CALIB_BIASREFBUF((*(uint32_t *)ADC_FUSES_BIASREFBUF_ADDR >> ADC_FUSES_BIASREFBUF_Pos)) |
+                ADC_CALIB_BIASCOMP((*(uint32_t *)ADC_FUSES_BIASCOMP_ADDR >> ADC_FUSES_BIASCOMP_Pos));
+
+    if (!ADC->SYNCBUSY.bit.SWRST) {
+        if (ADC->CTRLA.bit.ENABLE) {
+            ADC->CTRLA.bit.ENABLE = 0;
+            _watch_sync_adc();
+        }
+        ADC->CTRLA.bit.SWRST = 1;
+    }
+    _watch_sync_adc();
+
+    if (USB->DEVICE.CTRLA.bit.ENABLE) {
+        // if USB is enabled, we are running an 8 MHz clock.
+        // divide by 16 for a 500kHz ADC clock.
+        ADC->CTRLB.bit.PRESCALER = ADC_CTRLB_PRESCALER_DIV16_Val;
+    } else {
+        // otherwise it's 4 Mhz. divide by 8 for a 500kHz ADC clock.
+        ADC->CTRLB.bit.PRESCALER = ADC_CTRLB_PRESCALER_DIV8_Val;
+    }
+    ADC->CALIB.reg = calib_reg;
+    ADC->REFCTRL.bit.REFSEL = ADC_REFCTRL_REFSEL_INTVCC2_Val;
+    ADC->INPUTCTRL.bit.MUXNEG = ADC_INPUTCTRL_MUXNEG_GND_Val;
+    ADC->CTRLC.bit.RESSEL = ADC_CTRLC_RESSEL_16BIT_Val;
+    ADC->AVGCTRL.bit.SAMPLENUM = ADC_AVGCTRL_SAMPLENUM_16_Val;
+    ADC->SAMPCTRL.bit.SAMPLEN = 0;
+    ADC->INTENSET.reg = ADC_INTENSET_RESRDY;
+    ADC->CTRLA.bit.ENABLE = 1;
+    _watch_sync_adc();
+    // throw away one measurement after reference change (the channel doesn't matter).
+    _watch_get_analog_value(ADC_INPUTCTRL_MUXPOS_SCALEDCOREVCC);
+}
+
+void watch_enable_analog_input(const uint8_t pin) {
+    gpio_set_pin_direction(pin, GPIO_DIRECTION_OFF);
+    switch (pin) {
+        case A0:
+            gpio_set_pin_function(pin, PINMUX_PB04B_ADC_AIN12);
+            break;
+        case A1:
+            gpio_set_pin_function(pin, PINMUX_PB01B_ADC_AIN9);
+            break;
+        case A2:
+            gpio_set_pin_function(pin, PINMUX_PB02B_ADC_AIN10);
+            break;
+        case A3:
+            gpio_set_pin_function(pin, PINMUX_PB03B_ADC_AIN11);
+            break;
+        case A4:
+            gpio_set_pin_function(pin, PINMUX_PB00B_ADC_AIN8);
+            break;
+        default:
+            return;
+    }
+}
+
+uint16_t watch_get_analog_pin_level(const uint8_t pin) {
+    switch (pin) {
+        case A0:
+            return _watch_get_analog_value(ADC_INPUTCTRL_MUXPOS_AIN12_Val);
+        case A1:
+            return _watch_get_analog_value(ADC_INPUTCTRL_MUXPOS_AIN9_Val);
+        case A2:
+            return _watch_get_analog_value(ADC_INPUTCTRL_MUXPOS_AIN10_Val);
+        case A3:
+            return _watch_get_analog_value(ADC_INPUTCTRL_MUXPOS_AIN11_Val);
+        case A4:
+            return _watch_get_analog_value(ADC_INPUTCTRL_MUXPOS_AIN8_Val);
+        default:
+            return 0;
+    }
+}
+
+void watch_set_analog_num_samples(uint16_t samples) {
+    // ignore any input that's not a power of 2 (i.e. only one bit set)
+    if (__builtin_popcount(samples) != 1) return;
+    // if only one bit is set, counting the trailing zeroes is equivalent to log2(samples)
+    uint8_t sample_val = __builtin_ctz(samples);
+    // make sure the desired value is within range and set it, if so.
+    if (sample_val <= ADC_AVGCTRL_SAMPLENUM_1024_Val) {
+        ADC->AVGCTRL.bit.SAMPLENUM = sample_val;
+        _watch_sync_adc();
+    }
+}
+
+void watch_set_analog_sampling_length(uint8_t cycles) {
+    // for clarity the API asks the user how many cycles they want the measurement to take.
+    // but the ADC always needs at least one cycle; it just wants to know how many *extra* cycles we want.
+    // so we subtract one from the user-provided value, and clamp to the maximum.
+    ADC->SAMPCTRL.bit.SAMPLEN = (cycles - 1) & 0x3F;
+    _watch_sync_adc();
+}
+
+void watch_set_analog_reference_voltage(watch_adc_reference_voltage reference) {
+    ADC->CTRLA.bit.ENABLE = 0;
+
+    if (reference == ADC_REFERENCE_INTREF) SUPC->VREF.bit.VREFOE = 1;
+    else SUPC->VREF.bit.VREFOE = 0;
+
+    ADC->REFCTRL.bit.REFSEL = reference;
+    ADC->CTRLA.bit.ENABLE = 1;
+    _watch_sync_adc();
+    // throw away one measurement after reference change (the channel doesn't matter).
+    _watch_get_analog_value(ADC_INPUTCTRL_MUXPOS_SCALEDCOREVCC);
+}
+
+uint16_t watch_get_vcc_voltage(void) {
+    // stash the previous reference so we can restore it when we're done.
+    uint8_t oldref = ADC->REFCTRL.bit.REFSEL;
+
+    // if we weren't already using the internal reference voltage, select it now.
+    if (oldref != ADC_REFERENCE_INTREF) watch_set_analog_reference_voltage(ADC_REFERENCE_INTREF);
+
+    // get the data
+    uint32_t raw_val = _watch_get_analog_value(ADC_INPUTCTRL_MUXPOS_SCALEDIOVCC_Val);
+
+    // restore the old reference, if needed.
+    if (oldref != ADC_REFERENCE_INTREF) watch_set_analog_reference_voltage(oldref);
+
+    return (uint16_t)((raw_val * 1000) / (1024 * 1 << ADC->AVGCTRL.bit.SAMPLENUM));
+}
+
+inline void watch_disable_analog_input(const uint8_t pin) {
+    gpio_set_pin_function(pin, GPIO_PIN_FUNCTION_OFF);
+}
+
+inline void watch_disable_adc(void) {
+    ADC->CTRLA.bit.ENABLE = 0;
+    _watch_sync_adc();
+
+    MCLK->APBCMASK.reg &= ~MCLK_APBCMASK_ADC;
+}