drv: add library that can be used to read the battery level

doc/sphinx/drv.md

@@ -10,6 +10,7 @@ Libraries
 :caption: Contents
 
 _api/drv_as5048b
+_api/drv_battery
 _api/drv_hdlc
 _api/drv_imu
 _api/drv_ism330

doc/sphinx/examples.md

@@ -46,6 +46,7 @@ Libraries examples
 :maxdepth: 1
 
 _examples/01drv_as5048b
+_examples/01drv_battery
 _examples/01drv_imu
 _examples/01drv_ism330
 _examples/01drv_lis2mdl

drv/battery.h

@@ -0,0 +1,40 @@
+#ifndef __BATTERY_H
+#define __BATTERY_H
+
+/**
+ * @defgroup    drv_battery  Battery level measurement functions
+ * @ingroup     drv
+ * @brief       Functions for measuring battery level
+ *
+ * @{
+ * @file
+ * @author Alexandre Abadie <alexandre.abadie@inria.fr>
+ * @copyright Inria, 2025
+ * @}
+ */
+
+#include <stdint.h>
+
+// For reading the battery level
+#if defined(BOARD_DOTBOT_V3)
+#define DB_BATTERY_LEVEL_PIN (DB_SAADC_INPUT_AIN1)
+#else
+#define DB_BATTERY_LEVEL_PIN (DB_SAADC_INPUT_VDD)
+#endif
+
+/// Maximum battery level in millivolts
+#define DB_BATTERY_LEVEL_MAX_MV (3000)
+
+/**
+ * @brief Initialize the battery level measurement module
+ */
+void db_battery_level_init(void);
+
+/**
+ * @brief Read the battery level in millivolts
+ *
+ * @return Battery level in millivolts
+ */
+uint16_t db_battery_level_read(void);
+
+#endif  // __BATTERY_H

drv/battery/battery.c

@@ -0,0 +1,19 @@
+#include <stdio.h>
+
+#include "battery.h"
+
+#include "saadc.h"
+
+void db_battery_level_init(void) {
+    db_saadc_init(DB_SAADC_RESOLUTION_12BIT);
+}
+
+uint16_t db_battery_level_read(void) {
+    uint16_t value_12b = 0;
+    db_saadc_read(DB_BATTERY_LEVEL_PIN, &value_12b);
+    uint16_t voltage_mv = (uint16_t)(((float)value_12b / 4095) * 3600);
+    if (voltage_mv > DB_BATTERY_LEVEL_MAX_MV) {
+        voltage_mv = DB_BATTERY_LEVEL_MAX_MV;
+    }
+    return voltage_mv;
+}

drv/drv.emProject

@@ -14,6 +14,15 @@
     <file file_name="as5048b.c" />
     <file file_name="../as5048b.h" />
   </project>
+  <project Name="00drv_dotbot_battery">
+    <configuration
+      Name="Common"
+      project_dependencies="00bsp_saadc(bsp)"
+      project_directory="battery"
+      project_type="Library" />
+    <file file_name="battery.c" />
+    <file file_name="../battery.h" />
+  </project>
   <project Name="00drv_dotbot_hdlc">
     <configuration
       Name="Common"

projects/01drv_battery/README.md

@@ -0,0 +1 @@
+# Reads the battery level

projects/01drv_battery/main.c

@@ -0,0 +1,24 @@
+/**
+ * @file
+ * @ingroup samples_drv
+ * @author Alexandre Abadie <alexandre.abadie@inria.fr>
+ * @brief Simple application used to read and print the battery level
+ *
+ * @copyright Inria, 2025
+ *
+ */
+#include <nrf.h>
+#include <stdio.h>
+#include "timer.h"
+#include "battery.h"
+
+int main(void) {
+    db_timer_init(0);
+    db_battery_level_init();
+
+    while (1) {
+        uint16_t battery_level = db_battery_level_read();
+        printf("Battery level: %d mV\n", battery_level);
+        db_timer_delay_ms(0, 1000);
+    }
+}

projects/projects-bsp-drv.emProject

@@ -470,6 +470,30 @@
       <file file_name="$(ProjectDir)/../../nRF/System/cpu.c" />
     </folder>
   </project>
+  <project Name="01drv_battery">
+    <configuration
+      Name="Common"
+      project_dependencies="00drv_dotbot_battery(drv);00bsp_dotbot_board(bsp);00bsp_timer(bsp)"
+      project_directory="01drv_battery"
+      project_type="Executable" />
+    <folder Name="Setup">
+      <file file_name="$(ProjectDir)/../../nRF/Setup/$(Target)_flash_placement.xml" />
+      <file file_name="$(ProjectDir)/../../nRF/Setup/$(Target)_MemoryMap.xml">
+        <configuration Name="Common" file_type="Memory Map" />
+      </file>
+      <file file_name="../../nRF/Scripts/nRF_Target.js">
+        <configuration Name="Common" file_type="Reset Script" />
+      </file>
+    </folder>
+    <folder Name="Source">
+      <configuration Name="Common" filter="c;cpp;cxx;cc;h;s;asm;inc" />
+      <file file_name="main.c" />
+    </folder>
+    <folder Name="System">
+      <file file_name="$(ProjectDir)/../../nRF/System/$(Target)_system_init.c" />
+      <file file_name="$(ProjectDir)/../../nRF/System/cpu.c" />
+    </folder>
+  </project>
   <project Name="01drv_imu">
     <configuration
       Name="Common"