ADC works for measuring the battery voltage

code/b-parasite/Makefile

@@ -43,16 +43,14 @@ SRC_FILES += \
   $(SDK_ROOT)/components/boards/boards.c \
   $(SDK_ROOT)/integration/nrfx/legacy/nrf_drv_clock.c \
   $(SDK_ROOT)/integration/nrfx/legacy/nrf_drv_twi.c \
-  $(SDK_ROOT)/integration/nrfx/legacy/nrf_drv_uart.c \
   $(SDK_ROOT)/modules/nrfx/soc/nrfx_atomic.c \
   $(SDK_ROOT)/modules/nrfx/drivers/src/nrfx_clock.c \
   $(SDK_ROOT)/modules/nrfx/drivers/src/nrfx_gpiote.c \
   $(SDK_ROOT)/modules/nrfx/drivers/src/nrfx_rtc.c \
+  $(SDK_ROOT)/modules/nrfx/drivers/src/nrfx_saadc.c \
   $(SDK_ROOT)/modules/nrfx/drivers/src/nrfx_twi.c \
   $(SDK_ROOT)/modules/nrfx/drivers/src/prs/nrfx_prs.c \
   $(SDK_ROOT)/modules/nrfx/drivers/src/nrfx_pwm.c \
-  $(SDK_ROOT)/modules/nrfx/drivers/src/nrfx_uart.c \
-  $(SDK_ROOT)/modules/nrfx/drivers/src/nrfx_uarte.c \
   $(SDK_ROOT)/components/libraries/bsp/bsp.c \
   $(PROJ_DIR)/main.c \
   $(SDK_ROOT)/external/segger_rtt/SEGGER_RTT.c \
@@ -64,6 +62,7 @@ SRC_FILES += \
   $(SDK_ROOT)/components/softdevice/common/nrf_sdh.c \
   $(SDK_ROOT)/components/softdevice/common/nrf_sdh_ble.c \
   $(SDK_ROOT)/components/softdevice/common/nrf_sdh_soc.c \
+	$(PROJ_DIR)/prst/adc.c \
 	$(PROJ_DIR)/prst/ble.c \
 	$(PROJ_DIR)/prst/pwm.c \
 	$(PROJ_DIR)/prst/rtc.c \
@@ -220,6 +219,9 @@ CFLAGS += -DNRF_SD_BLE_API_VERSION=7
 CFLAGS += -DS140
 CFLAGS += -DSOFTDEVICE_PRESENT
 CFLAGS += -DEBUG
+# Setting -DDEBUG prints info via JLkinkRTTLogger, but hides the stack trace
+# when debugging with VSCode's Cortex Debug extension.
+# CFLAGS += -DDEBUG
 CFLAGS += -mcpu=cortex-m4
 CFLAGS += -mthumb -mabi=aapcs
 CFLAGS += -Wall -Werror

code/b-parasite/config/sdk_config.h

@@ -3361,7 +3361,7 @@
 // <e> NRFX_SAADC_ENABLED - nrfx_saadc - SAADC peripheral driver
 //==========================================================
 #ifndef NRFX_SAADC_ENABLED
-#define NRFX_SAADC_ENABLED 0
+#define NRFX_SAADC_ENABLED 1
 #endif
 // <o> NRFX_SAADC_CONFIG_RESOLUTION  - Resolution
 
@@ -4393,7 +4393,7 @@
 // <e> NRFX_UARTE_ENABLED - nrfx_uarte - UARTE peripheral driver
 //==========================================================
 #ifndef NRFX_UARTE_ENABLED
-#define NRFX_UARTE_ENABLED 1
+#define NRFX_UARTE_ENABLED 0
 #endif
 // <o> NRFX_UARTE0_ENABLED - Enable UARTE0 instance
 #ifndef NRFX_UARTE0_ENABLED
@@ -5411,7 +5411,7 @@
 // <e> SAADC_ENABLED - nrf_drv_saadc - SAADC peripheral driver - legacy layer
 //==========================================================
 #ifndef SAADC_ENABLED
-#define SAADC_ENABLED 0
+#define SAADC_ENABLED 1
 #endif
 // <o> SAADC_CONFIG_RESOLUTION  - Resolution
 
@@ -5883,7 +5883,7 @@
 // <e> UART_ENABLED - nrf_drv_uart - UART/UARTE peripheral driver - legacy layer
 //==========================================================
 #ifndef UART_ENABLED
-#define UART_ENABLED 1
+#define UART_ENABLED 0
 #endif
 // <o> UART_DEFAULT_CONFIG_HWFC  - Hardware Flow Control
 
@@ -7611,7 +7611,7 @@
 
 
 #ifndef NRF_FPRINTF_DOUBLE_ENABLED
-#define NRF_FPRINTF_DOUBLE_ENABLED 0
+#define NRF_FPRINTF_DOUBLE_ENABLED 1
 #endif
 
 // </h>
@@ -7784,8 +7784,9 @@
 
 // <i> Log data is buffered and can be processed in idle.
 
+// TODO(rbaron): optimize.
 #ifndef NRF_LOG_DEFERRED
-#define NRF_LOG_DEFERRED 1
+#define NRF_LOG_DEFERRED 0
 #endif
 
 // <q> NRF_LOG_FILTERS_ENABLED  - Enable dynamic filtering of logs.
@@ -8479,7 +8480,7 @@
 // <e> PWM_CONFIG_LOG_ENABLED - Enables logging in the module.
 //==========================================================
 #ifndef PWM_CONFIG_LOG_ENABLED
-#define PWM_CONFIG_LOG_ENABLED 0
+#define PWM_CONFIG_LOG_ENABLED 1
 #endif
 // <o> PWM_CONFIG_LOG_LEVEL  - Default Severity level
 
@@ -8690,7 +8691,7 @@
 // <e> SAADC_CONFIG_LOG_ENABLED - Enables logging in the module.
 //==========================================================
 #ifndef SAADC_CONFIG_LOG_ENABLED
-#define SAADC_CONFIG_LOG_ENABLED 0
+#define SAADC_CONFIG_LOG_ENABLED 1
 #endif
 // <o> SAADC_CONFIG_LOG_LEVEL  - Default Severity level
 

code/b-parasite/src/main.c

@@ -15,6 +15,7 @@
 #include "nrf_sdh.h"
 #include "nrf_sdh_ble.h"
 #include "nrf_soc.h"
+#include "prst/adc.h"
 #include "prst/ble.h"
 #include "prst/pwm.h"
 #include "prst/rtc.h"
@@ -54,28 +55,28 @@ static void power_manage(void) {
   nrf_pwr_mgmt_run();
 }
 
-static uint8_t data;
-
 // Here we need to be extra careful with what operations we do. This callback
 // has to return fast-ish, otherwise we hit some hard exceptions.
 static void rtc_callback() {
-  NRF_LOG_INFO("rtc callback running...\n");
+  NRF_LOG_INFO("Batt raw ");
   NRF_LOG_FLUSH();
   nrf_gpio_pin_set(PRST_LED_PIN);
   prst_shtc3_read_t temp_humi = prst_shtc3_read();
-  NRF_LOG_INFO("Read temp: " NRF_LOG_FLOAT_MARKER " oC",
-               NRF_LOG_FLOAT(temp_humi.temp_c));
   prst_pwm_init();
   prst_pwm_start();
-  // TODO: ADC.
-  nrf_delay_ms(500);
-  // TODO: PWM pin seems to be stuch on high after stop.
+  prst_adc_batt_read_t batt_read = prst_adc_batt_read();
   prst_pwm_stop();
-  prst_ble_update_adv_data(++data);
+  prst_ble_update_adv_data(batt_read.millivolts);
   prst_adv_start();
-  nrf_delay_ms(300);
+  nrf_delay_ms(200);
   prst_adv_stop();
   nrf_gpio_pin_clear(PRST_LED_PIN);
+  UNUSED_VARIABLE(batt_read);
+  UNUSED_VARIABLE(temp_humi);
+  NRF_LOG_INFO("Read batt: " NRF_LOG_FLOAT_MARKER " V (%d), %u mV",
+               NRF_LOG_FLOAT(batt_read.voltage), batt_read.raw, batt_read.millivolts);
+  NRF_LOG_INFO("Read temp: " NRF_LOG_FLOAT_MARKER " oC",
+               NRF_LOG_FLOAT(temp_humi.temp_c));
   NRF_LOG_FLUSH();
 }
 
@@ -84,10 +85,13 @@ int main(void) {
   leds_init();
   power_management_init();
   prst_ble_init();
+  prst_adc_init();
   prst_shtc3_init();
   prst_rtc_set_callback(rtc_callback);
   prst_rtc_init();
 
+  nrf_delay_ms(100);
+
   for (;;) {
     power_manage();
   }

code/b-parasite/src/prst/adc.c

@@ -0,0 +1,79 @@
+#include "prst/adc.h"
+
+#include <app_error.h>
+#include <nrf_drv_saadc.h>
+#include <nrf_log.h>
+#include <nrf_saadc.h>
+// #include <nrfx_saadc.h>
+
+#include "prst_config.h"
+
+// 10 bits resoltuion.
+#define PRST_ADC_RESOLUTION 10
+
+// #define PRST_ADC_BATT_INPUT NRF_SAADC_INPUT_VDD
+#define PRST_ADC_BATT_INPUT NRF_SAADC_INPUT_VDD
+#define PRST_ADC_BATT_CHANNEL 0
+
+// #define PRST_ADC_SOIL_INPUT NRF_SAADC_INPUT_AIN1
+// #define PRST_ADC_SOIL_CHANNEL 1
+
+// Unused, since we'll call the SAADC synchronously for now.
+// void saadc_callback(nrfx_saadc_evt_t const* p_event) {
+//   NRF_LOG_INFO("CB!", p_event->type)
+// }
+void saadc_callback(nrf_drv_saadc_evt_t const* p_event) {
+  if (p_event->type == NRF_DRV_SAADC_EVT_DONE) {
+    ret_code_t err_code;
+    uint16_t size = p_event->data.done.size;
+
+    err_code = nrf_drv_saadc_buffer_convert(p_event->data.done.p_buffer, size);
+    APP_ERROR_CHECK(err_code);
+
+    int i;
+    NRF_LOG_INFO("ADC event!");
+
+    for (i = 0; i < size; i++) {
+      NRF_LOG_INFO("%d", p_event->data.done.p_buffer[i]);
+    }
+  }
+}
+
+void prst_adc_init() {
+  nrf_saadc_channel_config_t batt_channel_config =
+      NRF_DRV_SAADC_DEFAULT_CHANNEL_CONFIG_SE(PRST_ADC_BATT_INPUT);
+
+  APP_ERROR_CHECK(nrf_drv_saadc_init(NULL, saadc_callback));
+
+  APP_ERROR_CHECK(
+      nrf_drv_saadc_channel_init(PRST_ADC_BATT_CHANNEL, &batt_channel_config));
+
+  // nrf_saadc_channel_config_t soil_channel_config =
+  //     NRFX_SAADC_DEFAULT_CHANNEL_CONFIG_SE(PRST_ADC_SOIL_INPUT);
+  // soil_channel_config.reference = NRF_SAADC_REFERENCE_VDD4;
+
+  // APP_ERROR_CHECK(
+  //     nrf_drv_saadc_channel_init(PRST_ADC_SOIL_CHANNEL,
+  //     &soil_channel_config));
+}
+
+prst_adc_batt_read_t prst_adc_batt_read() {
+  nrf_saadc_value_t result;
+  // *WARNING* this function is blocking, which is ot ideal but okay, but it
+  // *does not work* when oversampling is set! I had to manually disable
+  // SAADC_CONFIG_OVERSAMPLE in sdk_config.h.
+  APP_ERROR_CHECK(nrf_drv_saadc_sample_convert(PRST_ADC_BATT_CHANNEL, &result));
+  NRF_LOG_INFO("Read batt: here %d", result);
+  prst_adc_batt_read_t ret;
+  ret.raw = (uint16_t) result;
+  ret.voltage = (3.6 * result) / (1 << PRST_ADC_RESOLUTION);
+  ret.millivolts = ret.voltage * 1000;
+  return ret;
+}
+
+int16_t prst_adc_soil_read() {
+  nrf_saadc_value_t result = 0;
+  // APP_ERROR_CHECK(nrf_drv_saadc_sample_convert(PRST_ADC_SOIL_CHANNEL,
+  // &result));
+  return result;
+}

code/b-parasite/src/prst/adc.h

@@ -0,0 +1,18 @@
+#ifndef _PRST_ADC_H_
+#define _PRST_ADC_H_
+
+#include <stdint.h>
+
+typedef struct prst_adc_batt_val {
+  int16_t raw;
+  uint16_t millivolts;
+  double voltage;
+} prst_adc_batt_read_t;
+
+void prst_adc_init();
+
+prst_adc_batt_read_t prst_adc_batt_read();
+
+int16_t prst_adc_soil_read();
+
+#endif  // _PRST_ADC_H_

code/b-parasite/src/prst/ble.c

@@ -98,8 +98,9 @@ void prst_ble_init() {
   init_advertisement_data();
 }
 
-void prst_ble_update_adv_data(uint8_t n) {
-  service_data[0] = n;
+void prst_ble_update_adv_data(uint16_t batt_millivolts) {
+  service_data[0] = batt_millivolts >> 8;
+  service_data[1] = batt_millivolts & 0xff;
 
   // Encodes adv_data_ into .gap_adv_data_.
   uint32_t err_code = ble_advdata_encode(

code/b-parasite/src/prst/ble.h

@@ -11,6 +11,6 @@ void prst_adv_start();
 
 void prst_adv_stop();
 
-void prst_ble_update_adv_data(uint8_t n);
+void prst_ble_update_adv_data(uint16_t batt_millivolts);
 
 #endif  // _PRST_BLE_H_

code/b-parasite/src/prst/pwm.c

@@ -62,10 +62,7 @@ void prst_pwm_start() {
 }
 
 void prst_pwm_stop() {
-  // Careful when using wait_until_stopped! When calling this from within the
-  // RTC callback, somtimes I'm hitting a hard exception. I haven't figured it
-  // out yet, but probably some race condition for waiting + rtc?
-  APP_ERROR_CHECK(nrf_drv_pwm_stop(&m_pwm0, /*wait_until_stopped=*/false));
+  nrf_drv_pwm_stop(&m_pwm0, /*wait_until_stopped=*/true);
   nrf_drv_pwm_uninit(&m_pwm0);
   nrf_gpio_pin_clear(PRST_PWM_PIN);
 }

code/playground/nrf_sdk/saadc-vcc-nrf52832/saadc_gcc_nrf52.ld

@@ -5,8 +5,8 @@ GROUP(-lgcc -lc -lnosys)
 
 MEMORY
 {
-  FLASH (rx) : ORIGIN = 0x0, LENGTH = 0x80000
-  RAM (rwx) :  ORIGIN = 0x20000000, LENGTH = 0x10000
+  FLASH (rx) : ORIGIN = 0x27000, LENGTH = 0xd9000
+  RAM (rwx) :  ORIGIN = 0x20002300, LENGTH = 0x3dd00
 }
 
 SECTIONS
@@ -19,6 +19,18 @@ SECTIONS
   .mem_section_dummy_ram :
   {
   }
+  .cli_sorted_cmd_ptrs :
+  {
+    PROVIDE(__start_cli_sorted_cmd_ptrs = .);
+    KEEP(*(.cli_sorted_cmd_ptrs))
+    PROVIDE(__stop_cli_sorted_cmd_ptrs = .);
+  } > RAM
+  .fs_data :
+  {
+    PROVIDE(__start_fs_data = .);
+    KEEP(*(.fs_data))
+    PROVIDE(__stop_fs_data = .);
+  } > RAM
   .log_dynamic_data :
   {
     PROVIDE(__start_log_dynamic_data = .);
@@ -39,12 +51,66 @@ SECTIONS
   .mem_section_dummy_rom :
   {
   }
+  .sdh_soc_observers :
+  {
+    PROVIDE(__start_sdh_soc_observers = .);
+    KEEP(*(SORT(.sdh_soc_observers*)))
+    PROVIDE(__stop_sdh_soc_observers = .);
+  } > FLASH
+  .sdh_ble_observers :
+  {
+    PROVIDE(__start_sdh_ble_observers = .);
+    KEEP(*(SORT(.sdh_ble_observers*)))
+    PROVIDE(__stop_sdh_ble_observers = .);
+  } > FLASH
   .pwr_mgmt_data :
   {
     PROVIDE(__start_pwr_mgmt_data = .);
     KEEP(*(SORT(.pwr_mgmt_data*)))
     PROVIDE(__stop_pwr_mgmt_data = .);
   } > FLASH
+  .sdh_req_observers :
+  {
+    PROVIDE(__start_sdh_req_observers = .);
+    KEEP(*(SORT(.sdh_req_observers*)))
+    PROVIDE(__stop_sdh_req_observers = .);
+  } > FLASH
+  .sdh_state_observers :
+  {
+    PROVIDE(__start_sdh_state_observers = .);
+    KEEP(*(SORT(.sdh_state_observers*)))
+    PROVIDE(__stop_sdh_state_observers = .);
+  } > FLASH
+  .sdh_stack_observers :
+  {
+    PROVIDE(__start_sdh_stack_observers = .);
+    KEEP(*(SORT(.sdh_stack_observers*)))
+    PROVIDE(__stop_sdh_stack_observers = .);
+  } > FLASH
+    .nrf_queue :
+  {
+    PROVIDE(__start_nrf_queue = .);
+    KEEP(*(.nrf_queue))
+    PROVIDE(__stop_nrf_queue = .);
+  } > FLASH
+    .nrf_balloc :
+  {
+    PROVIDE(__start_nrf_balloc = .);
+    KEEP(*(.nrf_balloc))
+    PROVIDE(__stop_nrf_balloc = .);
+  } > FLASH
+    .cli_command :
+  {
+    PROVIDE(__start_cli_command = .);
+    KEEP(*(.cli_command))
+    PROVIDE(__stop_cli_command = .);
+  } > FLASH
+  .crypto_data :
+  {
+    PROVIDE(__start_crypto_data = .);
+    KEEP(*(SORT(.crypto_data*)))
+    PROVIDE(__stop_crypto_data = .);
+  } > FLASH
   .log_const_data :
   {
     PROVIDE(__start_log_const_data = .);
@@ -57,12 +123,6 @@ SECTIONS
     KEEP(*(SORT(.log_backends*)))
     PROVIDE(__stop_log_backends = .);
   } > FLASH
-    .nrf_balloc :
-  {
-    PROVIDE(__start_nrf_balloc = .);
-    KEEP(*(.nrf_balloc))
-    PROVIDE(__stop_nrf_balloc = .);
-  } > FLASH
 
 } INSERT AFTER .text
 

code/playground/nrf_sdk/saadc-vcc-nrf52832/saadc_gcc_nrf52832.ld

@@ -0,0 +1,70 @@
+/* Linker script to configure memory regions. */
+
+SEARCH_DIR(.)
+GROUP(-lgcc -lc -lnosys)
+
+MEMORY
+{
+  FLASH (rx) : ORIGIN = 0x0, LENGTH = 0x80000
+  RAM (rwx) :  ORIGIN = 0x20000000, LENGTH = 0x10000
+}
+
+SECTIONS
+{
+}
+
+SECTIONS
+{
+  . = ALIGN(4);
+  .mem_section_dummy_ram :
+  {
+  }
+  .log_dynamic_data :
+  {
+    PROVIDE(__start_log_dynamic_data = .);
+    KEEP(*(SORT(.log_dynamic_data*)))
+    PROVIDE(__stop_log_dynamic_data = .);
+  } > RAM
+  .log_filter_data :
+  {
+    PROVIDE(__start_log_filter_data = .);
+    KEEP(*(SORT(.log_filter_data*)))
+    PROVIDE(__stop_log_filter_data = .);
+  } > RAM
+
+} INSERT AFTER .data;
+
+SECTIONS
+{
+  .mem_section_dummy_rom :
+  {
+  }
+  .pwr_mgmt_data :
+  {
+    PROVIDE(__start_pwr_mgmt_data = .);
+    KEEP(*(SORT(.pwr_mgmt_data*)))
+    PROVIDE(__stop_pwr_mgmt_data = .);
+  } > FLASH
+  .log_const_data :
+  {
+    PROVIDE(__start_log_const_data = .);
+    KEEP(*(SORT(.log_const_data*)))
+    PROVIDE(__stop_log_const_data = .);
+  } > FLASH
+  .log_backends :
+  {
+    PROVIDE(__start_log_backends = .);
+    KEEP(*(SORT(.log_backends*)))
+    PROVIDE(__stop_log_backends = .);
+  } > FLASH
+    .nrf_balloc :
+  {
+    PROVIDE(__start_nrf_balloc = .);
+    KEEP(*(.nrf_balloc))
+    PROVIDE(__stop_nrf_balloc = .);
+  } > FLASH
+
+} INSERT AFTER .text
+
+
+INCLUDE "nrf_common.ld"