From df7700cdd71d90aee5e2f488e7fe1c0236476243 Mon Sep 17 00:00:00 2001
From: rbaron <rbaron@rbaron.net>
Date: Fri, 25 Nov 2022 23:42:40 +0100
Subject: [PATCH] Recalibrated. BLE sample seems to work e2e @ 2.7uA sleep :)

---
 code/nrf-connect/Kconfig        | 2 +-
 code/nrf-connect/prj.conf       | 8 +++-----
 code/nrf-connect/src/main.c     | 2 --
 code/nrf-connect/src/prst/adc.c | 7 ++++---
 code/nrf-connect/src/prst/adc.h | 1 +
 5 files changed, 9 insertions(+), 11 deletions(-)

diff --git a/code/nrf-connect/Kconfig b/code/nrf-connect/Kconfig
index 6e9512f..8ab20c9 100644
--- a/code/nrf-connect/Kconfig
+++ b/code/nrf-connect/Kconfig
@@ -16,7 +16,7 @@ endchoice  # PRST_NETWORK
 
 config PRST_SLEEP_DURATION_SEC
 	int "Sleep duration in seconds"
-	default 1
+	default 600
 
 ###
 ### BLE configs
diff --git a/code/nrf-connect/prj.conf b/code/nrf-connect/prj.conf
index ce9324f..dd84d36 100644
--- a/code/nrf-connect/prj.conf
+++ b/code/nrf-connect/prj.conf
@@ -1,6 +1,6 @@
-CONFIG_LOG=y
+# Enabling log has a big impact in power consumption. Only enable it while debugging.
+CONFIG_LOG=n
 CONFIG_PWM=y
-CONFIG_PWM_LOG_LEVEL_DBG=y
 CONFIG_CBPRINTF_FP_SUPPORT=y
 CONFIG_I2C=y
 CONFIG_ADC=y
@@ -9,12 +9,11 @@ CONFIG_GPIO=y
 CONFIG_BT=y
 CONFIG_BT_PERIPHERAL=y
 CONFIG_BT_DEBUG_LOG=n
-CONFIG_BT_DEVICE_NAME="para"
+CONFIG_BT_DEVICE_NAME="prst"
 CONFIG_BT_SETTINGS=n
 CONFIG_SETTINGS=n
 CONFIG_BT_CTLR_TX_PWR_PLUS_8=y
 
-CONFIG_CONSOLE=n
 CONFIG_SERIAL=n
 CONFIG_PM=y
 CONFIG_PM_DEVICE=y
@@ -25,4 +24,3 @@ CONFIG_CONSOLE=n
 CONFIG_RTT_CONSOLE=n
 
 CONFIG_PINCTRL=y
-
diff --git a/code/nrf-connect/src/main.c b/code/nrf-connect/src/main.c
index fe51d11..ee7e5e3 100644
--- a/code/nrf-connect/src/main.c
+++ b/code/nrf-connect/src/main.c
@@ -42,8 +42,6 @@ int main(void) {
     RET_IF_ERR(prst_ble_adv_start());
 
     k_sleep(K_SECONDS(CONFIG_PRST_BLE_ADV_DURATION_SEC));
-    k_msleep(200);
-    k_busy_wait(200 * 1000);
 
     RET_IF_ERR(prst_ble_adv_stop());
 
diff --git a/code/nrf-connect/src/prst/adc.c b/code/nrf-connect/src/prst/adc.c
index 4105876..9046798 100644
--- a/code/nrf-connect/src/prst/adc.c
+++ b/code/nrf-connect/src/prst/adc.c
@@ -38,8 +38,8 @@ static const struct adc_dt_spec adc_batt_spec =
 static inline float get_soil_moisture_percent(float battery_voltage,
                                               int16_t raw_adc_output) {
   const double x = battery_voltage;
-  const double dry = -12.9 * x * x + 111 * x + 228;
-  const double wet = -5.71 * x * x + 60.2 * x + 126;
+  const double dry = -11.7f * x * x + 101.0f * x + 306.0f;
+  const double wet = 3.42f * x * x - 4.98f * x + 19.0f;
   LOG_DBG("Raw %u | Batt: %.2f | Dry: %.2f | Wet: %.2f", raw_adc_output, x, dry,
           wet);
   return (raw_adc_output - dry) / (wet - dry);
@@ -96,7 +96,8 @@ int prst_adc_soil_read(float battery_voltage, prst_adc_soil_moisture_t* out) {
   // Turn off fast discharge circuit.
   RET_IF_ERR(gpio_pin_set_dt(&fast_disch_dt, 0));
 
-  out->percentage = get_soil_moisture_percent(battery_voltage, buf);
+  out->percentage =
+      MAX(0.0f, MIN(1.0f, get_soil_moisture_percent(battery_voltage, buf)));
   return 0;
 }
 
diff --git a/code/nrf-connect/src/prst/adc.h b/code/nrf-connect/src/prst/adc.h
index 2a1f66d..5ec3e9e 100644
--- a/code/nrf-connect/src/prst/adc.h
+++ b/code/nrf-connect/src/prst/adc.h
@@ -13,6 +13,7 @@ typedef struct {
   prst_adc_read_t adc_read;
   // A value from 0 (completely dry) to 2^10 (completely wet).
   uint16_t relative;
+  // In [0, 1.0].
   float percentage;
 } prst_adc_soil_moisture_t;