https://github.com/mongoose-os-libs/dallas-rmt

https://github.com/mongoose-os-libs/dallas-rmt

Last synced: 21 days ago
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• Host: GitHub
• URL: https://github.com/mongoose-os-libs/dallas-rmt
• Owner: mongoose-os-libs
• License: apache-2.0
• Created: 2017-11-29T09:33:24.000Z (almost 7 years ago)
• Default Branch: master
• Last Pushed: 2021-12-15T00:17:08.000Z (almost 3 years ago)
• Last Synced: 2024-07-31T21:52:48.046Z (4 months ago)
• Language: C++
• Size: 34.2 KB
• Stars: 1
• Watchers: 5
• Forks: 2
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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• awesome-mongoose-os - dallas-rmt

README

        
# Library to read Dallas temperature sensor using ESP32's RMT device

The library uses the `onewire-rmt` library. 

A pullup resistor (4.7k) must be connected between the data line of the sensor and Vcc.

# Example code in C++

```

#include 

#include "DallasRmt.h"

static DallasRmt* dallas = NULL;

static OnewireRmt* ow = NULL;

static int numDevices = 0;

static uint32_t readings = 0;

static void loop_onewire(void *arg)

{

    (void) arg;

    if (0 == numDevices) {

        LOG(LL_WARN, ("No device found"));

        return;

    }

    bool wait = dallas->getWaitForConversion();

    double start = mg_time();

    dallas->requestTemperatures();

    double end = mg_time();

    LOG(LL_WARN, ("wait=%d, conversionTime=%.2fms", wait, 1000.0 * (end - start)));

    uint8_t deviceAddress[8];

    for (int i = 0; i < numDevices; ++i) {

        float temp = dallas->getTempCByIndex(i);

        dallas->getAddress(deviceAddress, i);

        char buf[17];

        char*p = buf;

        for (int i = 0; i < 8; ++i) {

            p += snprintf(p, sizeof (buf) - 2 * i, "%02x", deviceAddress[i]);

        }

        LOG(LL_WARN, ("index=%d, address=%s, temp=%.2f, reading=%d", i, buf, temp, readings));

        readings++;

    }

}

extern "C"

enum mgos_app_init_result mgos_app_init(void)

{

    dallas = new DallasRmt();

    ow = new OnewireRmt(13 /*pin*/, 0 /*rmt_rx*/, 1 /*rmt_tx*/);

    dallas->setOneWire(ow);

    dallas->begin();

    numDevices = dallas->getDeviceCount();

    

    mgos_set_timer(3000, 1, loop_onewire, NULL);

    return MGOS_APP_INIT_SUCCESS;

}

```

# Example code in C

```

#include 

#include "mgos_dallas_rmt.h"

static DallasRmt* dallas = NULL;

static int numDevices = 0;

static uint32_t readings = 0;

static void readData() {

    char deviceAddress[8];

    for (int i = 0; i < numDevices; ++i) {

        float temp = mgos_dallas_rmt_get_tempc_by_index(dallas, i) / 100.0;

        mgos_dallas_rmt_get_address(dallas, deviceAddress, i);

        char buf[17];

        char*p = buf;

        for (int i = 0; i < 8; ++i) {

            p += snprintf(p, sizeof (buf) - 2 * i, "%02x", deviceAddress[i]);

        }

        LOG(LL_WARN, ("index=%d, address=%s, temp=%.2f, reading=%d", i, buf, temp, readings));

        readings++;

    }

}

static void owTimerCB(void * arg) {

    readData();

}

static void loop_onewire(void *arg) {

    (void) arg;

    if (0 == numDevices) {

        LOG(LL_WARN, ("No device found"));

        return;

    }

    bool wait = mgos_dallas_rmt_get_wait_for_conversion(dallas);

    double start = mg_time();

    mgos_dallas_rmt_request_temperatures(dallas);

    double end = mg_time();

    LOG(LL_WARN, ("wait=%d, conversionTime=%.2fms", wait, 1000.0 * (end - start)));

    if (wait) {

        readData();

    } else {

        mgos_set_timer(800, 0, owTimerCB, NULL);

    }

}

enum mgos_app_init_result mgos_app_init(void) {

    OnewireRmt* ow = mgos_onewire_rmt_create(13 /*pin*/, 0 /*rmt_rx*/, 1 /*rmt_tx*/);

    dallas = mgos_dallas_rmt_create(ow);

    

    mgos_dallas_rmt_begin(dallas);

    numDevices = mgos_dallas_rmt_get_device_count(dallas);

    

    int resolution = mgos_dallas_rmt_get_global_resolution(dallas);

    int16_t millis = mgos_dallas_rmt_millis_to_wait_for_conversion(dallas, resolution);

    LOG(LL_WARN, ("resolution=%d, millis=%d", resolution, millis));

    //mgos_dallas_rmt_set_wait_for_conversion(dallas, false);

    mgos_set_timer(3000, 1, loop_onewire, NULL);

    return MGOS_APP_INIT_SUCCESS;

}