https://github.com/tordwessman/r2bt

Simple BLE library for ESP32 used to expose JSON objects.
https://github.com/tordwessman/r2bt

Last synced: about 2 months ago
JSON representation

Simple BLE library for ESP32 used to expose JSON objects.

• Host: GitHub
• URL: https://github.com/tordwessman/r2bt
• Owner: TordWessman
• Created: 2023-11-13T11:18:30.000Z (about 1 year ago)
• Default Branch: main
• Last Pushed: 2023-11-15T20:13:28.000Z (about 1 year ago)
• Last Synced: 2023-11-15T21:27:32.453Z (about 1 year ago)
• Language: C
• Size: 24.4 KB
• Stars: 0
• Watchers: 1
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md

Awesome Lists containing this project

README

        
# R2BT

Simple Bluetooth Low Energy(BLE) abstraction library (tested for ESP-32).

It's intended to be used as a "variable storage" where a `R2BTDataContainer` represents a "variable".

Communicates using JSON-packages and is coupled to the `cJSON` library (https://github.com/DaveGamble/cJSON).

Example blob:

```

#include 

/// Override to access the delegate methods.

class AVariable: public R2BTDataContainer {

public:

    AVariable(uint16_t id) : R2BTDataContainer(id) { }

    // Callback when a container has been updated.

    void OnUpdate(cJSON *newValue, R2BTError *error) override {

        Serial.println("Got updated, yo!");  

    }

};

AVariable *aVariable;

R2BTHub *hub;

#define A_SERVICE_ID "aaaabbbb-1fb5-459e-8fcc-c5c9c331914b"

void setup() {

    Serial.begin(9600);

    aVariable = new AVariable(0x42); // The full characteristics id will be defined by `R2BTDataContainer_CHARACTERISTICS_ID_TEMPLATE`. `id` only denotes the first 4 bytes.

    hub = new R2BTHub("device_name", A_SERVICE_ID); // Device will be identified by `"device_name"` and `A_SERVICE_ID`

    // Create a cJSON object

    cJSON *json = cJSON_CreateObject();

    cJSON_AddStringToObject(json, "cause_of_death", "death by eating");

    // Instantiate the variable by adding it to the hub.

    hub->AddDataContainer(aVariable, json);

    // Free up the JSON object

    cJSON_Delete(json);

    hub->Start();

}

void loop() {

    //Code below will update (and broadcast) the value every 10 seconds:

    delay(10 * 1000);

    cJSON *newValue = cJSON_CreateObject();

    cJSON_AddStringToObject(newValue, "cause_of_death", "death by fishing");

    // Print current value

    char *currentValue = testEp->GenerateRawValue();

    Serial.print("Current value (before change): "); Serial.println(currentValue);

    free(currentValue);

    //Broadcast new value

    aVariable->SetValue(newValue);

    cJSON_Delete(newValue);

}

```