To facilitate over-the-air (OTA) firmware updates for the ESP32 using a C# application, you’ll need to prepare both the ESP32 firmware to handle OTA requests and write C# code to send the new firmware to the ESP32.
Here’s a step-by-step guide with the required code snippets.
Step 1: Preparing ESP32 Firmware for OTA
- OTA Code for ESP32: Use the Arduino IDE to program your ESP32. Include OTA capabilities in your ESP32 firmware.
- Update
ssidandpasswordwith your WiFi credentials. - This code sets up the ESP32 to receive OTA updates.
- Here’s a simplified example: –
#include <WiFi.h>
#include <ESPmDNS.h>
#include <WiFiUdp.h>
#include <ArduinoOTA.h>
const char* ssid = "yourSSID";
const char* password = "yourPASSWORD";
void setup()
{
Serial.begin(115200);
WiFi.begin(ssid, password);
while (WiFi.status() != WL_CONNECTED)
{
delay(1000);
Serial.println("Connecting to WiFi...");
}
// Port defaults to 3232
ArduinoOTA.setPort(3232);
// Hostname defaults to esp3232-[MAC]
ArduinoOTA.setHostname("myesp32");
// No authentication by default
ArduinoOTA.setPassword("admin");
ArduinoOTA
.onStart([]()
{
String type;
if(ArduinoOTA.getCommand() == U_FLASH)
{
type = "sketch";
}
else
{
// U_SPIFFS type = "filesystem";
}
// NOTE: if updating SPIFFS this would be the place to unmount SPIFFS using SPIFFS.end()
Serial.println("Start updating " + type);
})
.onEnd([]()
{
Serial.println("\nEnd");
})
.onProgress([](unsigned int progress, unsigned int total)
{
Serial.printf("Progress: %u%%\r", (progress / (total / 100)));
})
.onError([](ota_error_t error)
{
Serial.printf("Error[%u]: ", error);
if (error == OTA_AUTH_ERROR)
{
Serial.println("Auth Failed");
}
else if (error == OTA_BEGIN_ERROR)
{
Serial.println("Begin Failed");
}
else if (error == OTA_CONNECT_ERROR)
{
Serial.println("Connect Failed");
}
else if (error == OTA_RECEIVE_ERROR)
{
Serial.println("Receive Failed");
}
else if (error == OTA_END_ERROR)
{
Serial.println("End Failed");
}
});
ArduinoOTA.begin();
}
void loop()
{
ArduinoOTA.handle();
}Step 2: Creating the C# Application for OTA
- C# Application Setup:
- Create a new C# Console or Windows Forms application in Visual Studio.
- Implementing OTA Update Function in C#:
- Replace
espIpAddresswith the IP address of your ESP32. - Replace
firmwarePathwith the path to your compiled ESP32 firmware binary file. - Use the following code snippet to create a method that uploads the firmware file to the ESP32:
- Replace
using System;
using System.Net.Http;
using System.Threading.Tasks;
class Program {
static async Task Main(string[] args)
{
var espIpAddress = "192.168.1.100"; // Replace with your ESP32 IP
var string firmwarePath = @"C:\path\to\your\firmware.bin"; // Replace with your firmware file path
using (varclient = new HttpClient())
{
var form = newMultipartFormDataContent();
var firmwareData = System.IO.File.ReadAllBytes(firmwarePath);
form.Add(new ByteArrayContent(firmwareData, 0, firmwareData.Length), "firmware", "firmware.bin");
Console.WriteLine("Uploading firmware...");
var response = awaitclient.PostAsync($"http://{espIpAddress}/update", form);
if(response.IsSuccessStatusCode)
{
Console.WriteLine("Firmware upload successful.");
}
else
{
Console.WriteLine("Firmware upload failed.");
}
}
}
}Performing OTA Update
Run the C# application, ensuring the ESP32 is powered on and connected to the same network. The application will upload the new firmware to the ESP32, which will then apply the update and reboot.
Conclusion
This setup demonstrates the core components needed for OTA firmware updates for ESP32 using C#. Ensure proper error handling and secure the OTA process to prevent unauthorized access, especially in production environments.
