intermediate commit

src/power.cpp

@@ -0,0 +1,171 @@
+#include "arduino.h"
+#include "power.h"
+#include "hal.h"
+#include <esp_adc_cal.h>
+#include <driver/adc.h>
+#include "display.h"
+
+#define VOLTAGE_DIVIDER 2.08                    // Lora has 220k/100k voltage divider so need to reverse that reduction via (220k+100k)/100k on vbat GPIO37 or ADC1_1 (early revs were GPIO13 or ADC2_4 but do NOT use with WiFi.begin())
+#define DEFAULT_VREF 1100                        // Default VREF use if no e-fuse calibration
+#define VBATT_SAMPLE 500                         // Battery sample rate in ms
+#define VBATT_SMOOTH 20                          // Number of averages in sample
+#define ADC_READ_STABILIZE 50                    // in ms (delay from GPIO control and ADC connections times)
+#define LO_BATT_SLEEP_TIME 10 * 60 * 1000 * 1000 // How long when low batt to stay in sleep (us)
+#define __DEBUG 0                                // DEBUG Serial output
+
+uint16_t Sample();
+
+
+esp_adc_cal_characteristics_t *adc_chars;
+
+uint16_t voltage = 666;
+
+void powerInit(void)
+{
+#if (ENVIRONMENT == HELTECv21)
+  adc_chars = (esp_adc_cal_characteristics_t *)calloc(1, sizeof(esp_adc_cal_characteristics_t));
+  esp_adc_cal_value_t val_type = esp_adc_cal_characterize(ADC_UNIT_1, ADC_ATTEN_DB_6, ADC_WIDTH_BIT_12, DEFAULT_VREF, adc_chars);
+  adc1_config_width(ADC_WIDTH_BIT_12);
+  adc1_config_channel_atten(VBATT, ADC_ATTEN_DB_6);
+#else
+  // Use this for older V2.0 with VBatt reading wired to GPIO13
+  adc_chars = (esp_adc_cal_characteristics_t *)calloc(1, sizeof(esp_adc_cal_characteristics_t));
+  esp_adc_cal_value_t val_type = esp_adc_cal_characterize(ADC_UNIT_2, ADC_ATTEN_DB_6, ADC_WIDTH_BIT_12, DEFAULT_VREF, adc_chars);
+  adc2_config_channel_atten(VBATT, ADC_ATTEN_DB_6);
+#endif
+
+  if (val_type)
+    ; // Suppress warning
+
+  Serial.printf("ADC Calibration: ");
+  if (val_type == ESP_ADC_CAL_VAL_EFUSE_VREF)
+  {
+    Serial.printf("eFuse Vref\n");
+  }
+  else if (val_type == ESP_ADC_CAL_VAL_EFUSE_TP)
+  {
+    Serial.printf("Two Point\n");
+  }
+  else
+  {
+    Serial.printf("Default[%dmV]\n", DEFAULT_VREF);
+  }
+
+  Serial.println("Power init: ADC done");
+  // Prime the Sample register
+  for (uint8_t i = 0; i < VBATT_SMOOTH; i++)
+  {
+    Sample();
+  }
+  Serial.println("Power init: buffer done");
+  pinMode(VEXT, OUTPUT);
+  //digitalWrite(VEXT, LOW);   // ESP32 Lora v2.1 reads on GPIO37 when GPIO21 is low
+  //delay(ADC_READ_STABILIZE); // let GPIO stabilize
+  Serial.println("Power init done");
+}
+
+
+uint16_t powerGetVbatt(void)
+{
+  return voltage;
+}
+
+void powerHandler(void)
+{
+  voltage = Sample();
+  //displayDrawBatt(voltage, voltage < LIGHT_SLEEP_VOLTAGE);
+
+  if (voltage < MINBATT)
+  { // Low Voltage cut off shut down to protect battery as long as possible
+    displayDrawShutdown();
+    delay(2000);
+#if defined(__DEBUG) && __DEBUG > 0
+    Serial.printf(" !! Shutting down...low battery volotage: %dmV.\n", voltage);
+    delay(10);
+#endif
+    esp_sleep_enable_timer_wakeup(LO_BATT_SLEEP_TIME);
+    esp_deep_sleep_start();
+  }
+  else if (voltage < LIGHT_SLEEP_VOLTAGE)
+  { // Use light sleep once on battery
+    uint64_t s = VBATT_SAMPLE;
+#if defined(__DEBUG) && __DEBUG > 0
+    Serial.printf(" - Light Sleep (%dms)...battery volotage: %dmV.\n", (int)s, voltage);
+    delay(20);
+#endif
+    esp_sleep_enable_timer_wakeup(s * 1000); // Light Sleep does not flush buffer
+    esp_light_sleep_start();
+  }
+  delay(ADC_READ_STABILIZE);
+}
+
+
+// Heltec WiFi LoRa V2 battery read example
+// by Jeff McClain  jeff@themcclains.net
+//
+
+// Poll the proper ADC for VBatt on Heltec Lora 32 with GPIO21 toggled
+uint16_t ReadVBatt()
+{
+  int reading = 666;
+
+  digitalWrite(VEXT, LOW);   // ESP32 Lora v2.1 reads on GPIO37 when GPIO21 is low
+  delay(ADC_READ_STABILIZE); // let GPIO stabilize
+#if (defined(HELTEC_V2_1))
+  pinMode(VBATT, OPEN_DRAIN); // ADC GPIO37
+  reading = adc1_get_raw(VBATT);
+  pinMode(VBATT, INPUT); // Disconnect ADC before GPIO goes back high so we protect ADC from direct connect to VBATT (i.e. no divider)
+#else
+  pinMode(VBATT, OPEN_DRAIN); // ADC GPIO13
+  adc2_get_raw(VBATT, ADC_WIDTH_BIT_12, &reading);
+  pinMode(VBATT, INPUT); // Disconnect ADC before GPIO goes back high so we protect ADC from direct connect to VBATT (i.e. no divider
+#endif
+  uint16_t rawVoltage = esp_adc_cal_raw_to_voltage(reading, adc_chars);
+  //Serial.printf("battery rawvoltage = %i\n", rawVoltage);
+  rawVoltage *= VOLTAGE_DIVIDER;
+  //Serial.printf("battery sample = %i\n", rawVoltage);
+  //digitalWrite(VEXT, HIGH);   // ESP32 Lora v2.1 reads on GPIO37 when GPIO21 is low
+
+  return rawVoltage;
+
+}
+
+//  Use a buffer to average/sample ADC
+uint16_t Sample()
+{
+  static uint8_t i = 0;
+  static uint16_t samp[VBATT_SMOOTH];
+  static int32_t t = 0;
+  static bool f = true;
+  if (f)
+  {
+    for (uint8_t c = 0; c < VBATT_SMOOTH; c++)
+    {
+      samp[c] = 0;
+    }
+    f = false;
+  }             // Initialize the sample array first time
+  t -= samp[i]; // doing a rolling recording, so remove the old rolled around value out of total and get ready to put new one in.
+  if (t < 0)
+  {
+    t = 0;
+  }
+
+  // ADC read
+  samp[i] = ReadVBatt();
+#if defined(__DEBUG) && __DEBUG > 0
+  Serial.printf("ADC Raw Reading[%d]: %d", i, voltage);
+#endif
+  t += samp[i];
+
+  if (++i >= VBATT_SMOOTH)
+  {
+    i = 0;
+  }
+  uint16_t s = round(((float)t / (float)VBATT_SMOOTH));
+#if defined(__DEBUG) && __DEBUG > 0
+  Serial.printf("   Smoothed of %d/%d = %d\n", t, VBATT_S MOOTH, s);
+#endif
+
+  return s;
+}