esp-idf/examples/system/ulp_adc/main/ulp_adc_example_main.c
Ivan Grokhotkov 7fcc76fa06 ulp: fix calculation or ulp_run argument
The argument to ulp_run should be expressed in 32-bit words. Both the
address of ulp_entry and RTC_SLOW_MEM already are uint32_t*, so their
difference is the difference in addresses divided by sizeof(uint32_t).
Therefore the extra division by sizeof(uint32_t) is not needed.
2018-08-13 23:34:06 +03:00

93 lines
2.8 KiB
C

/* ULP Example
This example code is in the Public Domain (or CC0 licensed, at your option.)
Unless required by applicable law or agreed to in writing, this
software is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
CONDITIONS OF ANY KIND, either express or implied.
*/
#include <stdio.h>
#include <string.h>
#include "esp_sleep.h"
#include "nvs.h"
#include "nvs_flash.h"
#include "soc/rtc_cntl_reg.h"
#include "soc/sens_reg.h"
#include "driver/gpio.h"
#include "driver/rtc_io.h"
#include "driver/adc.h"
#include "driver/dac.h"
#include "esp32/ulp.h"
#include "ulp_main.h"
extern const uint8_t ulp_main_bin_start[] asm("_binary_ulp_main_bin_start");
extern const uint8_t ulp_main_bin_end[] asm("_binary_ulp_main_bin_end");
/* This function is called once after power-on reset, to load ULP program into
* RTC memory and configure the ADC.
*/
static void init_ulp_program();
/* This function is called every time before going into deep sleep.
* It starts the ULP program and resets measurement counter.
*/
static void start_ulp_program();
void app_main()
{
esp_sleep_wakeup_cause_t cause = esp_sleep_get_wakeup_cause();
if (cause != ESP_SLEEP_WAKEUP_ULP) {
printf("Not ULP wakeup\n");
init_ulp_program();
} else {
printf("Deep sleep wakeup\n");
printf("ULP did %d measurements since last reset\n", ulp_sample_counter & UINT16_MAX);
printf("Thresholds: low=%d high=%d\n", ulp_low_thr, ulp_high_thr);
ulp_last_result &= UINT16_MAX;
printf("Value=%d was %s threshold\n", ulp_last_result,
ulp_last_result < ulp_low_thr ? "below" : "above");
}
printf("Entering deep sleep\n\n");
start_ulp_program();
ESP_ERROR_CHECK( esp_sleep_enable_ulp_wakeup() );
esp_deep_sleep_start();
}
static void init_ulp_program()
{
esp_err_t err = ulp_load_binary(0, ulp_main_bin_start,
(ulp_main_bin_end - ulp_main_bin_start) / sizeof(uint32_t));
ESP_ERROR_CHECK(err);
/* Configure ADC channel */
/* Note: when changing channel here, also change 'adc_channel' constant
in adc.S */
adc1_config_channel_atten(ADC1_CHANNEL_6, ADC_ATTEN_DB_11);
adc1_config_width(ADC_WIDTH_BIT_12);
adc1_ulp_enable();
/* Set low and high thresholds, approx. 1.35V - 1.75V*/
ulp_low_thr = 1500;
ulp_high_thr = 2000;
/* Set ULP wake up period to 20ms */
ulp_set_wakeup_period(0, 20000);
/* Disable pullup on GPIO15, in case it is connected to ground to suppress
* boot messages.
*/
rtc_gpio_pullup_dis(GPIO_NUM_15);
rtc_gpio_hold_en(GPIO_NUM_15);
}
static void start_ulp_program()
{
/* Reset sample counter */
ulp_sample_counter = 0;
/* Start the program */
esp_err_t err = ulp_run(&ulp_entry - RTC_SLOW_MEM);
ESP_ERROR_CHECK(err);
}