Fixs PWM current consumption - SYSTEM ON sleep @ ~2.7uA

code/nrf-connect/boards/arm/bparasite_nrf52840/Kconfig

@@ -6,4 +6,9 @@ config BOARD_ENABLE_DCDC
 	select SOC_DCDC_NRF52X
 	default y
 
+config BOARD_ENABLE_DCDC_HV
+	bool "High Voltage DCDC converter"
+	select SOC_DCDC_NRF52X_HV
+	default y
+
 endif  # BOARD_BPARASITE_NRF52840

code/nrf-connect/boards/arm/bparasite_nrf52840/bparasite_nrf52840.dts

@@ -27,6 +27,7 @@
 	buttons {
 		compatible = "gpio-keys";
 		button0: button_0 {
+			// P0.12.
 			gpios = <&gpio0 12 (GPIO_PULL_UP | GPIO_ACTIVE_LOW)>;
 			label = "Push button switch 0";
 		};
@@ -34,9 +35,18 @@
 
 	soil_pwm: soil_pwm {
 		compatible = "pwm-fixed";
-		pwms = <&pwm0 0 PWM_MSEC(100) PWM_POLARITY_INVERTED>;
+		pwms = <&pwm0 0 PWM_MSEC(100) PWM_POLARITY_NORMAL>;
 		pulse = <PWM_MSEC(50)>;
 	};
+
+	ctrl {
+		compatible = "gpio-keys";
+		fast_disch: fast_disch {
+			// P1.10.
+			gpios = <&gpio1 10 GPIO_ACTIVE_HIGH>;
+			label = "Fast discharge circuitry";
+		};
+	};
 };
 
 &gpiote {
@@ -53,7 +63,7 @@
 
 &uart0 {
 	compatible = "nordic,nrf-uart";
-	status = "okay";
+	status = "disabled";
 	current-speed = <115200>;
 	pinctrl-0 = <&uart0_default>;
 	pinctrl-1 = <&uart0_sleep>;

code/nrf-connect/prj.conf

@@ -1,13 +1,28 @@
 CONFIG_LOG=y
 CONFIG_PWM=y
+CONFIG_PWM_LOG_LEVEL_DBG=y
 CONFIG_CBPRINTF_FP_SUPPORT=y
 CONFIG_I2C=y
 CONFIG_ADC=y
+CONFIG_GPIO=y
 
 CONFIG_BT=y
 CONFIG_BT_PERIPHERAL=y
-CONFIG_BT_DEBUG_LOG=y
+CONFIG_BT_DEBUG_LOG=n
 CONFIG_BT_DEVICE_NAME="para"
-# CONFIG_BT_SETTINGS=n
+CONFIG_BT_SETTINGS=n
-# CONFIG_SETTINGS=n
+CONFIG_SETTINGS=n
-CONFIG_BT_CTLR_TX_PWR_PLUS_8=y
+CONFIG_BT_CTLR_TX_PWR_PLUS_8=y
+
+CONFIG_CONSOLE=n
+CONFIG_SERIAL=n
+CONFIG_PM=y
+CONFIG_PM_DEVICE=y
+
+CONFIG_USE_SEGGER_RTT=y
+
+CONFIG_CONSOLE=n
+CONFIG_RTT_CONSOLE=n
+
+CONFIG_PINCTRL=y
+

code/nrf-connect/src/main.c

@@ -1,4 +1,7 @@
 #include <logging/log.h>
+#include <zephyr/pm/device.h>
+#include <zephyr/pm/pm.h>
+#include <zephyr/pm/policy.h>
 #include <zephyr/zephyr.h>
 
 #include "prst/adc.h"
@@ -38,8 +41,16 @@ int main(void) {
     RET_IF_ERR(prst_ble_adv_set_data(&sensors));
     RET_IF_ERR(prst_ble_adv_start());
 
-    k_msleep(5000);
+    k_sleep(K_SECONDS(2));
 
     RET_IF_ERR(prst_ble_adv_stop());
+
+    k_sleep(K_SECONDS(2));
+
+    prst_led_flash(1);
+
+    // Example: go to deep sleep.
+    pm_state_force(0u, &(struct pm_state_info){PM_STATE_SOFT_OFF, 0, 0});
+    k_sleep(K_SECONDS(2));
   }
 }

code/nrf-connect/src/prst/adc.c

@@ -74,14 +74,14 @@ int prst_adc_batt_read(prst_adc_read_t* out) {
 
 int prst_adc_soil_read(float battery_voltage, prst_adc_soil_moisture_t* out) {
   // Start PWM.
-  RET_IF_ERR(pwm_set_pulse_dt(&soil_pwm_dt, pulse));
+  RET_IF_ERR(pwm_set_dt(&soil_pwm_dt, soil_pwm_dt.period, pulse));
 
   k_msleep(30);
 
   RET_IF_ERR(read_adc_spec(&adc_soil_spec, &out->adc_read));
 
   // Stop PWM.
-  RET_IF_ERR(pwm_set_pulse_dt(&soil_pwm_dt, 0));
+  RET_IF_ERR(pwm_set_dt(&soil_pwm_dt, 0, 0));
 
   out->percentage = get_soil_moisture_percent(battery_voltage, buf);
   return 0;

code/nrf-connect/src/prst/button.c

@@ -22,7 +22,8 @@ static void button_pressed(const struct device *dev, struct gpio_callback *cb,
 int prst_button_init() {
   RET_IF_ERR(!device_is_ready(button.port));
   RET_IF_ERR(gpio_pin_configure_dt(&button, GPIO_INPUT));
-  RET_IF_ERR(gpio_pin_interrupt_configure_dt(&button, GPIO_INT_EDGE_TO_ACTIVE));
+  // EDGE interrupts consume more power! Just use a LEVEL one.
+  RET_IF_ERR(gpio_pin_interrupt_configure_dt(&button, GPIO_INT_LEVEL_ACTIVE));
   gpio_init_callback(&cb_data, button_pressed, BIT(button.pin));
   RET_IF_ERR(gpio_add_callback(button.port, &cb_data));
   return 0;