ESP32 Solar Lib

A robust and lightweight framework for buidling IoT APIs using the ESP32 chip.

Features

• Auto Connect to WiFi using Smart Config.
• Base API with reset, OTA update functionality.
• HTTPS OTA updates.
• API is secured using a client authentication key.
• Extremely fast response times.
• Easily expandable and customizable codebase to fit your needs.

Usage Example

Let's build a simple API that allows us to access info about the device.
Here is the Main .ino file with API configuration

#include "SolarWebService.h"
#include "WifiConfig.h"

/* Device Identifiers /**/

const char* authKey = "17iXyGkWGrnmXRi9JW9ygiCUIkCSiOK0"; // Auth Key to pass from the client device
const char* firmwareVersion = "MyDeviceOS-v-1.0";
const char* modelName = "Solar IOT Device";
const char* mdnsDomainName = "SolarIOTDevice1"; // Domain Name (Your API will be hosted on this domain)
const char* mdnsServiceName = "SolarIOTDevice"; // mDNS Service Type Name

/* Solar Library Object Pointers /**/

WifiConfig* wifiConfigInstance = nullptr;
SolarWebService* apiInstance = nullptr;

void setup() 
{
  
  wifiConfigInstance = new WifiConfig();
  wifiConfigInstance->connectToWifi();
  apiInstance = new SolarWebService(authKey);

  // Declare a new api "/info" path and implement it in a separate .ino file.
  // This will be our device info endpoint.
  apiInstance->server->on("/info", HTTP_GET, &getDeviceInfo);
  
  apiInstance->startMDNS(mdnsDomainName, mdnsServiceName);
  
}

void loop() 
{
  // put your main code here, to run repeatedly:
}

Let us now implement the endpoint.
Here is the API Path Implementations .ino file

void getDeviceInfo(AsyncWebServerRequest* request)
{
    // Use authKeyParamValid to verify the passed Auth Key
    if (SolarWebService::authKeyParamValid(request)) {

         // Create and send the response
         StaticJsonDocument<200> jsonResponse;
         StaticJsonDocument<200> responseData;
         
         responseData["os_version"] = firmwareVersion;
         responseData["uid"] = WiFi.macAddress();
         responseData["model_name"] = modelName;
         responseData["status"] = 200;

         jsonResponse["response"] = responseData;
      
         AsyncResponseStream* response = request->beginResponseStream("application/json");
      
         serializeJson(jsonResponse, *response);
          
         request->send(response);
         
    } else {
        // Invalid or no Auth Key -> Unauthorized request
        // handleRequest is defined in HttpResponseHandler.h
        handleRequest(request, 401);
    }
}

Dependencies + Installation

1. Make sure these are installed:
   

• ESPAsyncWebServer
• AsyncTCP for ESPAsyncWebServer
• ArduinoJSON - download from the Arduino IDE library manager

2) Move the SolarCore folder to your libraries directory - Done!

Base Paths

Defined in PathHandlers.h and WebService.h

/update

Params:

• authkey: Client Auth Key.
• url: New Firmware Binary URL.

Notes:
Firmware host must be signed by set Root CA (DigiCert High Assurance EV Root CA by default). Defined in OTA.h

/reset

Params:

• authkey: Client Auth Key.

Security

Please assess potential threats before using this library.
OTA updates are done over HTTPS. The API is locked by a client auth key.
Smart Config passes WiFi credentials without encryption.
This Library doesn't doesn't support HTTPS out of the box to be lightweight.

About

If you have any questions, you can reach me here: Leon.Vladimirov@gmail.com