From 5cfd69479a315078a2802253cea685ed24289380 Mon Sep 17 00:00:00 2001
From: rbaron <rbaron@rbaron.net>
Date: Mon, 8 Aug 2022 19:17:40 +0200
Subject: [PATCH] Advertises while in deep sleep.

Related to the investigation in #48
---
 code/b-parasite/config/prst_config.h |  2 +-
 code/b-parasite/src/main.c           | 58 ++++++++++++++++++----------
 code/b-parasite/src/prst/rtc.c       |  5 ++-
 code/b-parasite/src/prst/rtc.h       |  4 ++
 4 files changed, 45 insertions(+), 24 deletions(-)

diff --git a/code/b-parasite/config/prst_config.h b/code/b-parasite/config/prst_config.h
index 49b405e..faba1e1 100644
--- a/code/b-parasite/config/prst_config.h
+++ b/code/b-parasite/config/prst_config.h
@@ -44,7 +44,7 @@
 
 #define PRST_BLE_ADV_NAME "prst"
 // Total time spend advertising.
-#define PRST_BLE_ADV_TIME_IN_MS 1000
+#define PRST_BLE_ADV_TIME_IN_S 1
 // Interval between advertising packets.
 // From the specs, this value has to be greater or equal 20ms.
 #define PRST_BLE_ADV_INTERVAL_IN_MS 30
diff --git a/code/b-parasite/src/main.c b/code/b-parasite/src/main.c
index 9370c9d..b7becdf 100644
--- a/code/b-parasite/src/main.c
+++ b/code/b-parasite/src/main.c
@@ -17,6 +17,13 @@
 // A small wrap-around counter for deduplicating BLE packets on the receiver.
 static uint8_t run_counter = 0;
 
+typedef enum {
+  SLEEPING,
+  ADVERTISING,
+} State;
+
+static State state = SLEEPING;
+
 static void log_init(void) {
   APP_ERROR_CHECK(NRF_LOG_INIT(NULL));
   NRF_LOG_DEFAULT_BACKENDS_INIT();
@@ -59,35 +66,44 @@ static void rtc_callback() {
 #if PRST_BLINK_LED
   nrf_gpio_pin_set(PRST_LED_PIN);
 #endif
-  prst_shtc3_read_t temp_humi = prst_shtc3_read();
-  nrf_gpio_pin_set(PRST_FAST_DISCH_PIN);
-  prst_pwm_init();
-  prst_pwm_start();
-  prst_adc_batt_read_t batt_read = prst_adc_batt_read();
-  prst_adc_soil_moisture_t soil_read = prst_adc_soil_read(batt_read.voltage);
-  prst_pwm_stop();
-  nrf_gpio_pin_clear(PRST_FAST_DISCH_PIN);
 
-  uint16_t lux = 0;
+  if (state == SLEEPING) {
+    prst_shtc3_read_t temp_humi = prst_shtc3_read();
+    nrf_gpio_pin_set(PRST_FAST_DISCH_PIN);
+    prst_pwm_init();
+    prst_pwm_start();
+    prst_adc_batt_read_t batt_read = prst_adc_batt_read();
+    prst_adc_soil_moisture_t soil_read = prst_adc_soil_read(batt_read.voltage);
+    prst_pwm_stop();
+    nrf_gpio_pin_clear(PRST_FAST_DISCH_PIN);
+
+    uint16_t lux = 0;
 #if PRST_HAS_LDR || PRST_HAS_PHOTOTRANSISTOR
-  nrf_gpio_pin_set(PRST_PHOTO_V_PIN);
-  nrf_delay_ms(50);
-  prst_adc_photo_sensor_t photo_read = prst_adc_photo_read(batt_read.voltage);
-  lux = photo_read.brightness;
-  nrf_gpio_pin_clear(PRST_PHOTO_V_PIN);
+    nrf_gpio_pin_set(PRST_PHOTO_V_PIN);
+    nrf_delay_ms(50);
+    prst_adc_photo_sensor_t photo_read = prst_adc_photo_read(batt_read.voltage);
+    lux = photo_read.brightness;
+    nrf_gpio_pin_clear(PRST_PHOTO_V_PIN);
 #endif
 
-  prst_ble_update_adv_data(batt_read.millivolts, temp_humi.temp_celsius,
-                           temp_humi.humidity, soil_read.relative, lux,
-                           run_counter);
-  prst_adv_start();
-  nrf_delay_ms(PRST_BLE_ADV_TIME_IN_MS);
-  prst_adv_stop();
+    prst_ble_update_adv_data(batt_read.millivolts, temp_humi.temp_celsius,
+                             temp_humi.humidity, soil_read.relative, lux,
+                             run_counter);
+
+    state = ADVERTISING;
+    prst_adv_start();
+    prst_rtc_set_timer(PRST_BLE_ADV_TIME_IN_S);
+    run_counter++;
+  } else if (state == ADVERTISING) {
+    prst_adv_stop();
+    state = SLEEPING;
+    prst_rtc_set_timer(PRST_DEEP_SLEEP_IN_SECONDS);
+  }
 #if PRST_BLINK_LED
   nrf_gpio_pin_clear(PRST_LED_PIN);
 #endif
+
   NRF_LOG_FLUSH();
-  run_counter++;
 }
 
 int main(void) {
diff --git a/code/b-parasite/src/prst/rtc.c b/code/b-parasite/src/prst/rtc.c
index 2f0db11..1a66bd9 100644
--- a/code/b-parasite/src/prst/rtc.c
+++ b/code/b-parasite/src/prst/rtc.c
@@ -34,13 +34,14 @@ void prst_rtc_init() {
   // Disable events we're not interested in so they don't trigger interrupts.
   nrf_drv_rtc_tick_disable(&rtc_);
   nrf_drv_rtc_overflow_disable(&rtc_);
+}
 
+void prst_rtc_set_timer(uint16_t seconds) {
   // Make sure we're counting from 0.
   nrf_drv_rtc_counter_clear(&rtc_);
 
   // Set compare channel to trigger interrupt after specified time.
-  err_code = nrf_drv_rtc_cc_set(&rtc_, 2, PRST_DEEP_SLEEP_IN_SECONDS * 8, true);
-  APP_ERROR_CHECK(err_code);
+  APP_ERROR_CHECK(nrf_drv_rtc_cc_set(&rtc_, 2, seconds * 8, true));
 
   // Power on RTC instance.
   nrf_drv_rtc_enable(&rtc_);
diff --git a/code/b-parasite/src/prst/rtc.h b/code/b-parasite/src/prst/rtc.h
index 9cebe6d..cb4ca58 100644
--- a/code/b-parasite/src/prst/rtc.h
+++ b/code/b-parasite/src/prst/rtc.h
@@ -1,10 +1,14 @@
 #ifndef _PRST_RTC_H_
 #define _PRST_RTC_H_
 
+#include <stdint.h>
+
 typedef void (*prst_rtc_callback_t)(void);
 
 void prst_rtc_set_callback(prst_rtc_callback_t cb);
 
 void prst_rtc_init();
 
+void prst_rtc_set_timer(uint16_t seconds);
+
 #endif  // _PRST_RTC_H_
\ No newline at end of file