This commit is contained in:
Morgan 'ARR\!' Allen 2022-07-19 21:23:40 -07:00
commit 005264adc1
4 changed files with 123 additions and 0 deletions

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CMakeLists.txt Normal file
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idf_component_register(SRCS
"main/esp32-gp2y.c"
INCLUDE_DIRS "include"
)

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README.md Normal file
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# ESP32 GP2Y Dust Sensor
## Install
Designed to be used as an `esp-idf component`. Suggested usage is with `git submodule`
```
git submodule add https://git.oit.cloud/morgan/esp32-gp2y.git components/esp32-gp2y/
git submodule update --init
```
## API
### `typedef gp2y_cfg_t`
`float K` Sensitivity. Default: 0.5
`float offset_voltage` Voltage level at 0ug/m3 dust. Defaults to 0.6v, dynamically lowers.
`int8_t pin_led` Pin to pulse LED on.
`adc1_channel_t adc_channel` ADC channel to read on. See IDF Guide to get pin to channel reference.
`adc_unit_t adc_unit` ADC unit to read on.
### `int32_t gp2y_read(gp2y_cfg_t *cfg, uint8_t samples)`
Passing a pointer to `gp2y_cfg_t` and number of samples to take. 100 is a good starting point.
## Example
```
#include <stdio.h>
#include <unistd.h>
#include "driver/gpio.h"
#include "driver/adc.h"
#include "esp32-gp2y.h"
#define PIN_LED 5
void app_main() {
gp2y_cfg_t gp2y_cfg = GP2Y_DEFAULT_CFG;
gp2y_cfg.adc_channel = channel;
gp2y_cfg.pin_led = PIN_LED;
gpio_config_t io_conf;
io_conf.intr_type = GPIO_INTR_DISABLE;
io_conf.mode = GPIO_MODE_OUTPUT;
io_conf.pin_bit_mask = (1ULL<<gp2y_cfg.pin_led);
io_conf.pull_down_en = 1;
io_conf.pull_up_en = 0;
gpio_config(&io_conf);
adc1_config_channel_atten(gp2y_cfg.adc_channel, ADC_ATTEN_DB_11);
while (1) {
printf("aqi: %dug/m3\n", gp2y_read(&gp2y_cfg, 100));
vTaskDelay(1000 / portTICK_PERIOD_MS);
}
}
```

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include/esp32-gp2y.h Normal file
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#ifndef _LORA32_H__
#define _LORA32_H__
typedef struct {
float K;
float offset_voltage;
int8_t pin_led;
adc1_channel_t adc_channel;
adc_unit_t adc_unit;
} gp2y_cfg_t;
#define GP2Y_DEFAULT_CFG {\
.K = 0.5,\
.offset_voltage = 0.6,\
.pin_led = -1,\
.adc_channel = -1\
}
int32_t gp2y_read(gp2y_cfg_t *cfg, uint8_t samples);
#endif // _ESP32_GP2Y_H__

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main/esp32-gp2y.c Normal file
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#include <string.h>
#include <unistd.h>
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "driver/adc.h"
#include "driver/gpio.h"
#include "esp_log.h"
#include "esp32-gp2y.h"
int32_t gp2y_read(gp2y_cfg_t *cfg, uint8_t samples) {
int32_t accum = 0;
for(uint8_t i = 0; i < samples; i++) {
portMUX_TYPE myMutex = portMUX_INITIALIZER_UNLOCKED;
taskENTER_CRITICAL(&myMutex);
gpio_set_level(cfg->pin_led, 0);
usleep(280);
accum += adc1_get_raw(cfg->adc_channel);
gpio_set_level(cfg->pin_led, 1);
taskEXIT_CRITICAL(&myMutex);
usleep(9620);
}
float avg_adc = (accum / samples);
float avg_volt = avg_adc / 4095 * 3.3;
float dV = avg_volt - cfg->offset_voltage;
// recalibrate offset_volt to lowest value seen
if(dV < 0) {
dV = 0;
cfg->offset_voltage = avg_volt;
}
return dV / cfg->K * 100.0;
}