From e96562e36df96ca755d527e479e597ae4e4e09e1 Mon Sep 17 00:00:00 2001
From: Selene ToyKeeper
Date: Fri, 18 Aug 2017 18:12:17 -0600
Subject: Some early ideas for Round Table.  Nothing close to compile-able yet.

---
 RoundTable/round-table.c | 367 +++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 367 insertions(+)
 create mode 100644 RoundTable/round-table.c

(limited to 'RoundTable/round-table.c')

diff --git a/RoundTable/round-table.c b/RoundTable/round-table.c
new file mode 100644
index 0000000..6cd1b10
--- /dev/null
+++ b/RoundTable/round-table.c
@@ -0,0 +1,367 @@
+#include "tk-attiny.h"
+
+//
+typedef uint8_t (*EventCallbackPtr)(EventPtr event, uint16_t arg);
+typedef uint8_t EventCallback(EventPtr event, uint16_t arg);
+// FIXME: Why does a state need a number?  Why not just a function pointer?
+//        (I don't think it actually needs a number...)
+typedef struct State {
+    uint8_t num;
+    EventCallback event_callback;
+} State;
+typedef struct State* StatePtr;
+
+volatile StatePtr current_state;
+#define EV_MAX_LEN 16
+volatile uint8_t current_event[EV_MAX_LEN];
+
+volatile int16_t voltage;
+#ifdef USE_THERMAL_REGULATION
+volatile int16_t temperature;
+#endif
+
+#define A_ENTER_STATE     1
+#define A_LEAVE_STATE     2
+#define A_TICK            3
+#define A_PRESS           4
+#define A_HOLD_START      5
+#define A_HOLD_TICK       6
+#define A_RELEASE         7
+#define A_RELEASE_TIMEOUT 8
+// TODO: add events for over/under-heat conditions (with parameter for severity)
+#define A_OVERHEATING     9
+#define A_UNDERHEATING    10
+// TODO: add events for low voltage conditions
+#define A_VOLTAGE_LOW     11
+#define A_VOLTAGE_CRITICAL 12
+
+// TODO: maybe compare events by number instead of pointer?
+//       (number = index in event types array)
+//       (comparison would use full event content, but send off index to callbacks)
+//       (saves space by using uint8_t instead of a pointer)
+//       (also eliminates the need to duplicate single-entry events like for voltage or timer tick)
+
+// Event types
+typedef PROGMEM const uint8_t Event;
+typedef Event* EventPtr;
+Event EV_enter_state[] = {
+    A_ENTER_STATE,
+    0 } ;
+Event EV_leave_state[] = {
+    A_LEAVE_STATE,
+    0 } ;
+Event EV_tick[] = {
+    A_TICK,
+    0 } ;
+Event EV_press[] = {
+    A_PRESS,
+    0 };
+// shouldn't normally happen, but UI might reset event while button is down
+// so a release with no recorded prior hold could be possible
+Event EV_release[] = {
+    A_RELEASE,
+    0 };
+Event EV_press_release[] = {
+    A_PRESS,
+    A_RELEASE,
+    0 };
+#define EV_1click EV_press_release_timeout
+Event EV_press_release_timeout[] = {
+    A_PRESS,
+    A_RELEASE,
+    A_RELEASE_TIMEOUT,
+    0 };
+#define EV_hold EV_press_hold
+// FIXME: Should holds use "start+tick" or just "tick" with a tick number?
+//        Or "start+tick" with a tick number?
+Event EV_press_hold[] = {
+    A_PRESS,
+    A_HOLD_TIMEOUT,
+    0 };
+Event EV_press_hold_release[] = {
+    A_PRESS,
+    A_HOLD_TIMEOUT,
+    A_RELEASE,
+    0 };
+Event EV_press_release_press[] = {
+    A_PRESS,
+    A_RELEASE,
+    A_PRESS,
+    0 };
+Event EV_press_release_press_release[] = {
+    A_PRESS,
+    A_RELEASE,
+    A_PRESS,
+    A_RELEASE,
+    0 };
+#define EV_2clicks EV_press_release_press_release_timeout
+Event EV_press_release_press_release_timeout[] = {
+    A_PRESS,
+    A_RELEASE,
+    A_PRESS,
+    A_RELEASE,
+    A_RELEASE_TIMEOUT,
+    0 };
+// ... and so on
+
+// A list of event types for easy iteration
+EventPtr event_sequences[] = {
+    EV_press,
+    EV_press_release,
+    EV_press_release_timeout,
+    EV_press_release_press,
+    EV_press_release_press_release,
+    EV_press_release_press_release_timeout,
+    // ...
+};
+
+// TODO: move this to a separate UI-specific file
+/*
+State states[] = {
+
+};
+*/
+
+// TODO? add events to a queue when inside an interrupt
+//       instead of calling the event functions directly?
+//       (then empty the queue in main loop?)
+
+// TODO? new delay() functions which handle queue consumption?
+// TODO? new interruptible delay() functions?
+
+//static uint8_t ticks_since_last_event = 0;  // TODO: 16 bits?
+
+void WDT_tick() {
+    timer ++;
+
+    //static uint8_t hold_ticks = 0;  // TODO: 16 bits?
+
+    // callback on each timer tick
+    emit(EV_tick, timer);
+
+    // if time since last event exceeds timeout,
+    // append timeout to current event sequence, then
+    // send event to current state callback
+    // //hold_event(ticks)
+    // //emit(EV_press_hold, hold_ticks);
+    // emit_current(hold_ticks);
+    // or
+    // //release_timeout()
+    // //emit(EV_press_release_timeout, 0);
+    // emit_current(0);
+
+    // add 4-step voltage / temperature thing?
+    // with averaged values,
+    // once every N ticks?
+}
+
+void button_change_interrupt() {
+    // TODO: debounce a little
+
+    //ticks_since_last_event = 0;  // something happened
+
+    // TODO: add event to current sequence
+
+    // check if sequence matches any defined sequences
+    // if so, send event to current state callback
+    emit_current(0);
+}
+
+uint8_t emit_current(uint16_t arg) {
+    uint8_t err = 1;
+    for (uint8_t i=0; i<sizeof(event_sequences); i++) {
+        if (events_match(event_sequences[i], current_event)) {
+            err = emit(event_sequences[i], arg);
+            break;
+        }
+    }
+    return err;
+}
+
+#define events_match(a,b) compare_event_sequences(a,b)
+uint8_t compare_event_sequences(uint8_t *a, uint8_t *b) {
+}
+
+void empty_event_sequence() {
+    for(uint8_t i=0; i<EV_MAX_LEN; i++) current_event[i] = 0;
+}
+
+void append_event(uint8_t ev_type) {
+    ticks_since_last_event = 0;  // something happened
+    uint8_t i;
+    for(i=0; current_event[i], i<EV_MAX_LEN; i++);
+    if (i < EV_MAX_LEN) {
+        current_event[i] = ev_type;
+    } else {
+        // TODO: ... something?
+    }
+}
+
+// TODO: stack for states, to allow shared utility states like "input a number"
+//       and such, which return to the previous state after finishing
+// TODO: if callback doesn't handle current event,
+//       pass event to next state on stack?
+//       Callback return values:
+//       0: event handled normally
+//       1: event not handled
+//       255: error (not sure what this would even mean though, or what difference it would make)
+// TODO: function to call stacked callbacks until one returns "handled"
+uint8_t emit(EventPtr event, uint16_t arg) {
+    // TODO: implement
+    for(;;) {
+        uint8_t err = foo.callback(event, arg);
+        if (! err) return 0;
+    }
+    return 1;  // event not handled
+}
+
+uint8_t push_state(State *new_state) {
+    // TODO: implement
+}
+
+State * pop_state() {
+    // TODO: implement
+}
+
+uint8_t set_state(State *new_state) {
+    pop_state();
+    return push_state(new_state);
+}
+
+uint8_t _set_state(State *new_state) {
+    // call old state-exit hook (don't use stack)
+    current_state.callback(EV_leave_state, 0);
+    // set new state
+    current_state = new_state;
+    // call new state-enter hook (don't use stack)
+    current_state.callback(EV_enter_state, 0);
+}
+
+// TODO: implement
+ISR(WDT_vect) {
+}
+
+// TODO: implement?  (or is it better done in main()?)
+ISR(ADC_vect) {
+    static uint8_t adc_step = 0;
+    static uint8_t lvp_timer = 0;
+    #define LVP_TIMER_START 255  // TODO: calibrate this value
+
+    #ifdef USE_THERMAL_REGULATION
+    #define NUM_THERMAL_VALUES 4
+    #define ADC_STEPS 4
+    static int16_t temperature_values[NUM_THERMAL_VALUES];
+    #else
+    #define ADC_STEPS 2
+    #endif
+
+    int16_t measurement = ADC;  // latest 10-bit ADC reading
+
+    adc_step = (adc_step + 1) & (ADC_STEPS-1);
+
+    // TODO: voltage
+    // TODO: if low, callback EV_voltage_low / EV_voltage_critical
+    //       (but only if it has been more than N ticks since last call)
+    // if (lvp_timer) {
+    //     lvp_timer --;
+    // } else {
+    //     if (voltage is low) {
+    //         uint8_t err = emit(EV_voltage_low, 0);
+    //         if (!err) lvp_timer = LVP_TIMER_START;
+    //     }
+    // }
+
+    // TODO: temperature
+
+    // start another measurement for next time
+    #ifdef USE_THERMAL_REGULATION
+    if (adc_step < 2) ADMUX = ADMUX_VCC;
+    else ADMUX = ADMUX_THERM;
+    #else
+    ADMUX = ADMUX_VCC;
+    #endif
+}
+
+inline void ADC_on()
+{
+    // read voltage on VCC by default
+    // disable digital input on VCC pin to reduce power consumption
+    //DIDR0 |= (1 << ADC_DIDR);  // FIXME: unsure how to handle for VCC pin
+    // VCC / 1.1V reference
+    ADMUX = ADMUX_VCC;
+    // enable, start, prescale
+    ADCSRA = (1 << ADEN) | (1 << ADSC) | ADC_PRSCL;
+}
+
+// low-power standby mode used while off but power still connected
+#define standby_mode sleep_until_eswitch_pressed
+void sleep_until_eswitch_pressed()
+{
+    WDT_off();
+    ADC_off();
+
+    // TODO: make sure switch isn't currently pressed
+    while (switch_pressed()) {}
+
+    PCINT_on();  // wake on e-switch event
+
+    sleep_enable();
+    sleep_bod_disable();
+    sleep_cpu();  // wait here
+
+    // something happened; wake up
+    sleep_disable();
+    PCINT_off();
+    ADC_on();
+    WDT_on();
+}
+
+// boot-time tasks
+/* Define this in your RoundTable recipe
+void setup() {
+}
+*/
+
+void main() {
+    // Don't allow interrupts while booting
+    cli();
+    WDT_off();
+    PCINT_off();
+
+    // TODO: configure PWM channels
+    #if PWM_CHANNELS == 1
+    #elif PWM_CHANNELS == 2
+    #elif PWM_CHANNELS == 3
+    #elif PWM_CHANNELS == 4
+    // FIXME: How exactly do we do PWM on channel 4?
+    #endif
+
+    // TODO: turn on ADC?
+    // TODO: configure e-switch
+    //PORTB = (1 << SWITCH_PIN);  // e-switch is the only input
+    //PCMSK = (1 << SWITCH_PIN);  // pin change interrupt uses this pin
+
+    // TODO: configure sleep mode
+    set_sleep_mode(SLEEP_MODE_PWR_DOWN);
+
+    // Read config values and saved state
+    // restore_state();  // TODO
+
+    // TODO: handle long press vs short press (or even medium press)?
+
+    // TODO: call recipe's setup
+    setup();
+
+    // all booted -- turn interrupts back on
+    PCINT_on();
+    WDT_on();
+    sei();
+
+    // main loop
+    while (1) {
+        // TODO: update e-switch press state
+        // TODO: if wait queue not empty, process and pop first item in queue
+        // TODO: check voltage?
+        // TODO: check temperature?
+    }
+}
-- 
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