From e4663df50093261091bad7380bbd9d5bf8f015f5 Mon Sep 17 00:00:00 2001
From: Jannes <jannes@magnusso.nz>
Date: Sat, 19 Apr 2025 16:00:18 +0200
Subject: [PATCH] add deep sleep mode

---
 esp32_readout/display.cpp                     |  5 +++
 esp32_readout/display.h                       |  1 +
 esp32_readout/env.h                           |  8 +++++
 .../{readout_test.ino => esp32_readout.ino}   | 33 +++++++++++++++++++
 4 files changed, 47 insertions(+)
 rename esp32_readout/{readout_test.ino => esp32_readout.ino} (74%)

diff --git a/esp32_readout/display.cpp b/esp32_readout/display.cpp
index c799e4c..4879c19 100644
--- a/esp32_readout/display.cpp
+++ b/esp32_readout/display.cpp
@@ -34,4 +34,9 @@ void Display::print_weight(double val) {
   this->_display->setCursor(12, this->mid_x);
   this->_display->printf("%.2f g", val);
   this->_display->refresh();
+}
+
+void Display::clear() {
+  this->_display->clearDisplay();
+  this->_display->refresh();
 }
\ No newline at end of file
diff --git a/esp32_readout/display.h b/esp32_readout/display.h
index cc89794..f7faa0f 100644
--- a/esp32_readout/display.h
+++ b/esp32_readout/display.h
@@ -20,6 +20,7 @@
       void setup();
       void print(const char* text);
       void print_weight(double weight);
+      void clear();
   };
 
 #endif
\ No newline at end of file
diff --git a/esp32_readout/env.h b/esp32_readout/env.h
index df1ff75..4931d74 100644
--- a/esp32_readout/env.h
+++ b/esp32_readout/env.h
@@ -1,5 +1,8 @@
 #ifndef ENV
   #define ENV
+  #include <Arduino.h>
+  #include "driver/rtc_io.h"
+
   #include <BLEDevice.h>
   #include <BLEUtils.h>
   #include <BLEScan.h>
@@ -9,6 +12,11 @@
   #include <Adafruit_GFX.h>
   #include <Fonts/FreeSans9pt7b.h>
 
+  /********************* General ****************************/
+  #define BUTTON_PIN_BITMASK(GPIO) (1ULL << GPIO)
+  #define WAKEUP_GPIO              GPIO_NUM_1
+  #define SLEEP_GPIO               1
+
   /********************* NAU7802 ****************************/
 
   #define LDO NAU7802_3V3
diff --git a/esp32_readout/readout_test.ino b/esp32_readout/esp32_readout.ino
similarity index 74%
rename from esp32_readout/readout_test.ino
rename to esp32_readout/esp32_readout.ino
index bd19af1..35f900b 100644
--- a/esp32_readout/readout_test.ino
+++ b/esp32_readout/esp32_readout.ino
@@ -5,6 +5,7 @@ Display display;
 Adafruit_NAU7802 nau;
 unsigned long _millis = 0;
 int32_t val = 0;
+bool goToSleep = False;
 #if BLE
   BLEServer *pServer = NULL;
   BLECharacteristic *millisCharacteristic = NULL;
@@ -26,10 +27,42 @@ int32_t val = 0;
   };
 #endif
 
+void print_wakeup_reason() {
+  esp_sleep_wakeup_cause_t wakeup_reason;
+
+  wakeup_reason = esp_sleep_get_wakeup_cause();
+
+  switch (wakeup_reason) {
+    case ESP_SLEEP_WAKEUP_EXT0:     Serial.println("Wakeup caused by external signal using RTC_IO"); break;
+    case ESP_SLEEP_WAKEUP_EXT1:     Serial.println("Wakeup caused by external signal using RTC_CNTL"); break;
+    case ESP_SLEEP_WAKEUP_TIMER:    Serial.println("Wakeup caused by timer"); break;
+    case ESP_SLEEP_WAKEUP_TOUCHPAD: Serial.println("Wakeup caused by touchpad"); break;
+    case ESP_SLEEP_WAKEUP_ULP:      Serial.println("Wakeup caused by ULP program"); break;
+    default:                        Serial.printf("Wakeup was not caused by deep sleep: %d\n", wakeup_reason); break;
+  }
+}
+
+void IRAM_ATTR startSleep() {
+  display.clear();
+
+  esp_sleep_enable_ext0_wakeup(WAKEUP_GPIO, 1);
+
+  rtc_gpio_pullup_dis(WAKEUP_GPIO);
+  rtc_gpio_pulldown_en(WAKEUP_GPIO);
+
+  esp_deep_sleep_start();
+}
+
 void setup() {
   Serial.begin(115200);
   display.setup();
 
+  print_wakeup_reason();
+
+  /**** setup sleep interrupt ******/
+  pinMode(SLEEP_GPIO, INPUT);
+  attachInterrupt(digitalPinToInterrupt(SLEEP_GPIO), startSleep, FALLING);
+
   if (! nau.begin()) {
     Serial.println("Failed to find NAU7802");
     while (1) delay(10);  // Don't proceed.