From cfedb2eaf4a0d62969ff05307ac40d4f1cdab2d9 Mon Sep 17 00:00:00 2001
From: Selene ToyKeeper
Date: Sun, 17 Jun 2018 18:18:38 -0600
Subject: Implemented halfsleep mode. Will probably change it quite a bit
 though, so I'm checking in changes first. Needs to be "tick during standby"
 instead of "half sleep".

---
 spaghetti-monster/fsm-events.h  |  6 ++++++
 spaghetti-monster/fsm-standby.c | 38 +++++++++++++++++++++++++++++++-------
 spaghetti-monster/fsm-standby.h |  7 +++++--
 spaghetti-monster/fsm-wdt.c     | 17 +++++++++++++++++
 spaghetti-monster/fsm-wdt.h     |  4 ++++
 5 files changed, 63 insertions(+), 9 deletions(-)

diff --git a/spaghetti-monster/fsm-events.h b/spaghetti-monster/fsm-events.h
index 2721303..84e9ea2 100644
--- a/spaghetti-monster/fsm-events.h
+++ b/spaghetti-monster/fsm-events.h
@@ -64,6 +64,7 @@ static volatile uint16_t ticks_since_last_event = 0;
 #define A_OVERHEATING     9
 #define A_UNDERHEATING    10
 #define A_VOLTAGE_LOW     11
+#define A_HALFSLEEP_TICK  12
 //#define A_VOLTAGE_CRITICAL 12
 #define A_DEBUG           255  // test event for debugging
 
@@ -83,6 +84,11 @@ Event EV_reenter_state[] = {
 Event EV_tick[] = {
     A_TICK,
     0 } ;
+#ifdef USE_HALFSLEEP_MODE
+Event EV_halfsleep_tick[] = {
+    A_HALFSLEEP_TICK,
+    0 } ;
+#endif
 #ifdef USE_LVP
 Event EV_voltage_low[] = {
     A_VOLTAGE_LOW,
diff --git a/spaghetti-monster/fsm-standby.c b/spaghetti-monster/fsm-standby.c
index b90ccea..8e51dda 100644
--- a/spaghetti-monster/fsm-standby.c
+++ b/spaghetti-monster/fsm-standby.c
@@ -31,7 +31,17 @@
 #define standby_mode sleep_until_eswitch_pressed
 void sleep_until_eswitch_pressed()
 {
+    #ifdef USE_HALFSLEEP_MODE
+    //uint16_t sleep_counter = 0;
+    if (halfsleep_mode) {
+        // set WDT to slow mode
+        wdt_reset();
+        WDTCR |= (1<<WDCE) | (1<<WDE);  // Start timed sequence
+        WDTCR = (1<<WDIE) | 5;          // Enable interrupt every 0.5s
+    } else
+    #endif
     WDT_off();
+
     ADC_off();
 
     // make sure switch isn't currently pressed
@@ -41,15 +51,29 @@ void sleep_until_eswitch_pressed()
 
     PCINT_on();  // wake on e-switch event
 
-    // configure sleep mode
-    set_sleep_mode(SLEEP_MODE_PWR_DOWN);
+    #ifdef USE_HALFSLEEP_MODE
+    while (halfsleep_mode) {
+        f_wdt = 0;  // detect if WDT was what caused a wake-up
+    #endif
+        // configure sleep mode
+        set_sleep_mode(SLEEP_MODE_PWR_DOWN);
 
-    sleep_enable();
-    sleep_bod_disable();
-    sleep_cpu();  // wait here
+        sleep_enable();
+        sleep_bod_disable();
+        sleep_cpu();  // wait here
 
-    // something happened; wake up
-    sleep_disable();
+        // something happened; wake up
+        sleep_disable();
+
+        #ifdef USE_HALFSLEEP_MODE
+        // determine what woke us up... WDT or PCINT
+        if (! f_wdt) {  // PCINT went off
+            halfsleep_mode = 0;
+        }
+        #endif
+    #ifdef USE_HALFSLEEP_MODE
+    }
+    #endif
 
     #ifdef USE_THERMAL_REGULATION
     // forget what the temperature was last time we were on
diff --git a/spaghetti-monster/fsm-standby.h b/spaghetti-monster/fsm-standby.h
index 0b410fa..bd362a3 100644
--- a/spaghetti-monster/fsm-standby.h
+++ b/spaghetti-monster/fsm-standby.h
@@ -25,6 +25,11 @@
 // set this to nonzero to enter standby mode next time the system is idle
 volatile uint8_t go_to_standby = 0;
 
+#ifdef USE_HALFSLEEP_MODE
+// half-sleep "twilight" mode with WDT on but running slowly
+volatile uint8_t halfsleep_mode = 0;
+#endif
+
 #define standby_mode sleep_until_eswitch_pressed
 void sleep_until_eswitch_pressed();
 
@@ -34,6 +39,4 @@ void sleep_until_eswitch_pressed();
 void idle_mode();
 #endif
 
-// TODO: half-sleep "twilight" mode with WDT on but running slowly
-
 #endif
diff --git a/spaghetti-monster/fsm-wdt.c b/spaghetti-monster/fsm-wdt.c
index ff96ffb..06b0b6d 100644
--- a/spaghetti-monster/fsm-wdt.c
+++ b/spaghetti-monster/fsm-wdt.c
@@ -45,6 +45,23 @@ inline void WDT_off()
 
 // clock tick -- this runs every 16ms (62.5 fps)
 ISR(WDT_vect) {
+    #ifdef USE_HALFSLEEP_MODE
+    f_wdt = 1;  // WDT event happened
+
+    static uint16_t sleep_counter = 0;
+    // handle halfsleep mode specially
+    if (halfsleep_mode) {
+        // emit a halfsleep tick, and process it
+        emit(EV_halfsleep_tick, sleep_counter);
+        sleep_counter ++;
+        process_emissions();
+        //if (! halfsleep_mode)
+        //    sleep_counter = 0;
+        return;
+    }
+    sleep_counter = 0;
+    #endif
+
     // detect and emit button change events
     uint8_t was_pressed = button_last_state;
     uint8_t pressed = button_is_pressed();
diff --git a/spaghetti-monster/fsm-wdt.h b/spaghetti-monster/fsm-wdt.h
index 74851af..1173382 100644
--- a/spaghetti-monster/fsm-wdt.h
+++ b/spaghetti-monster/fsm-wdt.h
@@ -25,4 +25,8 @@
 void WDT_on();
 inline void WDT_off();
 
+#ifdef USE_HALFSLEEP_MODE
+volatile uint8_t f_wdt = 0;
+#endif
+
 #endif
-- 
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