我正在通过GSM执行ESP32 OTA。我在网上找到了一些示例代码，根据我的板连接对其进行了轻微修改，并能够成功地执行固件更新。
我使用lilygo ESP32 GSM开发板。
然而，让我感到沮丧的是，我无法从底层理解代码中真正发生的事情。在我继续我的项目之前，我真的很想了解。
我的OTA更新的完整代码：
#include <Update.h>
#define TINY_GSM_MODEM_SIM800
// Increase RX buffer
#define TINY_GSM_RX_BUFFER 1030
const char apn[] = "omnitel";
const char user[] = "omni";
const char pass[] = "omni";
#define MODEM_RST 5
#define MODEM_PWRKEY 4
#define MODEM_POWER_ON 23
#define MODEM_TX 27
#define MODEM_RX 26
#define LED_GPIO 13
#define LED_ON HIGH
#define LED_OFF LOW
#define SerialAT Serial1
#include <TinyGsmClient.h>
#include <CRC32.h>
#include "FS.h"
#include "SPIFFS.h"
#ifdef DUMP_AT_COMMANDS
#include <StreamDebugger.h>
StreamDebugger debugger(SerialAT, Serial);
TinyGsm modem(debugger);
#else
TinyGsm modem(SerialAT);
#endif
TinyGsmClient client(modem);
const char server[] = "myesptestserver.ddns.net";
const int port = 80;
const char resource[] = "/esp.bin"; //here de bin file
uint32_t knownCRC32 = 0x6f50d767;
uint32_t knownFileSize = 1024; // In case server does not send it
void setup()
{
SerialAT.begin(115200, SERIAL_8N1, MODEM_RX, MODEM_TX);
// Set console baud rate
Serial.begin(115200);
setupModem();
delay(10);
if (!SPIFFS.begin(true))
{
Serial.println("SPIFFS Mount Failed");
return;
}
SPIFFS.format();
listDir(SPIFFS, "/", 0);
// Set GSM module baud rate
delay(3000);
// Restart takes quite some time
// To skip it, call init() instead of restart()
Serial.println("Initializing modem...");
modem.restart();
String modemInfo = modem.getModemInfo();
Serial.print("Modem: ");
Serial.println(modemInfo);
// Unlock your SIM card with a PIN
//modem.simUnlock("1234");
}
void loop()
{
Serial.print("Waiting for network...");
if (!modem.waitForNetwork())
{
Serial.println(" fail");
delay(10000);
return;
}
Serial.println(" OK");
Serial.print("Connecting to ");
Serial.print(apn);
if (!modem.gprsConnect(apn, user, pass))
{
Serial.println(" fail");
delay(10000);
return;
}
Serial.println(" OK");
Serial.print("Connecting to ");
Serial.print(server);
// if you get a connection, report back via serial:
if (!client.connect(server, port))
{
Serial.println(" fail");
delay(10000);
return;
}
Serial.println(" OK");
// Make a HTTP request:
client.print(String("GET ") + resource + " HTTP/1.0rn");
client.print(String("Host: ") + server + "rn");
client.print("Connection: closernrn");
long timeout = millis();
while (client.available() == 0)
{
if (millis() - timeout > 5000L)
{
Serial.println(">>> Client Timeout !");
client.stop();
delay(10000L);
return;
}
}
Serial.println("Reading header");
uint32_t contentLength = knownFileSize;
File file = SPIFFS.open("/update.bin", FILE_APPEND);
while (client.available())
{
String line = client.readStringUntil('n');
line.trim();
//Serial.println(line); // Uncomment this to show response header
line.toLowerCase();
if (line.startsWith("content-length:"))
{
contentLength = line.substring(line.lastIndexOf(':') + 1).toInt();
}
else if (line.length() == 0)
{
break;
}
}
timeout = millis();
uint32_t readLength = 0;
CRC32 crc;
unsigned long timeElapsed = millis();
printPercent(readLength, contentLength);
while (readLength < contentLength && client.connected() && millis() - timeout < 10000L)
{
int i = 0;
while (client.available())
{
// read file data to spiffs
if (!file.print(char(client.read())))
{
Serial.println("Appending file");
}
//Serial.print((char)c); // Uncomment this to show data
//crc.update(c);
readLength++;
if (readLength % (contentLength / 13) == 0)
{
printPercent(readLength, contentLength);
}
timeout = millis();
}
}
file.close();
printPercent(readLength, contentLength);
timeElapsed = millis() - timeElapsed;
Serial.println();
client.stop();
Serial.println("stop client");
modem.gprsDisconnect();
Serial.println("gprs disconnect");
Serial.println();
float duration = float(timeElapsed) / 1000;
/*
Serial.print("Tamaño de Archivo: ");
Serial.println(contentLength);
Serial.print("Leido: ");
Serial.println(readLength);
Serial.print("Calculado. CRC32: 0x");
Serial.println(crc.finalize(), HEX);
Serial.print("Conocido CRC32: 0x");
Serial.println(knownCRC32, HEX);
Serial.print("Bajado en: ");
Serial.print(duration);
Serial.println("s");
Serial.println("Se genera una espera de 3 segundos");
for (int i = 0; i < 3; i++)
{
Serial.print(String(i) + "...");
delay(1000);
}
*/
//readFile(SPIFFS, "/update.bin");
updateFromFS();
// Do nothing forevermore
while (true)
{
delay(1000);
}
}
void appendFile(fs::FS &fs, const char *path, const char *message)
{
Serial.printf("Appending to file: %sn", path);
File file = fs.open(path, FILE_APPEND);
if (!file)
{
Serial.println("Failed to open file for appending");
return;
}
if (file.print(message))
{
Serial.println("APOK");
}
else
{
Serial.println("APX");
}
}
void readFile(fs::FS &fs, const char *path)
{
Serial.printf("Reading file: %sn", path);
File file = fs.open(path);
if (!file || file.isDirectory())
{
Serial.println("Failed to open file for reading");
return;
}
Serial.print("Read from file: ");
while (file.available())
{
Serial.write(file.read());
delayMicroseconds(100);
}
}
void writeFile(fs::FS &fs, const char *path, const char *message)
{
Serial.printf("Writing file: %sn", path);
File file = fs.open(path, FILE_WRITE);
if (!file)
{
Serial.println("Failed to open file for writing");
return;
}
if (file.print(message))
{
Serial.println("File written");
}
else
{
Serial.println("Write failed");
}
}
void listDir(fs::FS &fs, const char *dirname, uint8_t levels)
{
Serial.printf("Listing directory: %sn", dirname);
File root = fs.open(dirname);
if (!root)
{
Serial.println("Failed to open directory");
return;
}
if (!root.isDirectory())
{
Serial.println("Not a directory");
return;
}
File file = root.openNextFile();
while (file)
{
if (file.isDirectory())
{
Serial.print(" DIR : ");
Serial.println(file.name());
if (levels)
{
listDir(fs, file.name(), levels - 1);
}
}
else
{
Serial.print(" FILE: ");
Serial.print(file.name());
Serial.print(" SIZE: ");
Serial.println(file.size());
}
file = root.openNextFile();
}
}
void deleteFile(fs::FS &fs, const char *path)
{
Serial.printf("Deleting file: %sn", path);
if (fs.remove(path))
{
Serial.println("File deleted");
}
else
{
Serial.println("Delete failed");
}
}
void updateFromFS()
{
File updateBin = SPIFFS.open("/update.bin");
if (updateBin)
{
if (updateBin.isDirectory())
{
Serial.println("Directory error");
updateBin.close();
return;
}
size_t updateSize = updateBin.size();
if (updateSize > 0)
{
Serial.println("Starting update");
performUpdate(updateBin, updateSize);
}
else
{
Serial.println("Error, archivo vacío");
}
updateBin.close();
// whe finished remove the binary from sd card to indicate end of the process
//fs.remove("/update.bin");
}
else
{
Serial.println("no such binary");
}
}
void performUpdate(Stream &updateSource, size_t updateSize)
{
if (Update.begin(updateSize))
{
size_t written = Update.writeStream(updateSource);
if (written == updateSize)
{
Serial.println("Writes : " + String(written) + " successfully");
}
else
{
Serial.println("Written only : " + String(written) + "/" + String(updateSize) + ". Retry?");
}
if (Update.end())
{
Serial.println("OTA finished!");
if (Update.isFinished())
{
Serial.println("Restart ESP device!");
ESP.restart();
}
else
{
Serial.println("OTA not fiished");
}
}
else
{
Serial.println("Error occured #: " + String(Update.getError()));
}
}
else
{
Serial.println("Cannot beggin update");
}
}
void printPercent(uint32_t readLength, uint32_t contentLength)
{
// If we know the total length
if (contentLength != -1)
{
Serial.print("r ");
Serial.print((100.0 * readLength) / contentLength);
Serial.print('%');
}
else
{
Serial.println(readLength);
}
}
void setupModem()
{
#ifdef MODEM_RST
// Keep reset high
pinMode(MODEM_RST, OUTPUT);
digitalWrite(MODEM_RST, HIGH);
#endif
pinMode(MODEM_PWRKEY, OUTPUT);
pinMode(MODEM_POWER_ON, OUTPUT);
// Turn on the Modem power first
digitalWrite(MODEM_POWER_ON, HIGH);
// Pull down PWRKEY for more than 1 second according to manual requirements
digitalWrite(MODEM_PWRKEY, HIGH);
delay(100);
digitalWrite(MODEM_PWRKEY, LOW);
delay(1000);
digitalWrite(MODEM_PWRKEY, HIGH);
// Initialize the indicator as an output
pinMode(LED_GPIO, OUTPUT);
digitalWrite(LED_GPIO, LED_OFF);
}
据我所知，代码的以下部分读取存储在服务器中的二进制文件，并将其读取到SPIFFS内存中：
while (readLength < contentLength && client.connected() && millis() - timeout < 10000L)
{
int i = 0;
while (client.available())
{
// read file data to spiffs
if (!file.print(char(client.read())))
{
Serial.println("Appending file");
}
//Serial.print((char)c); // Uncomment this to show data
//crc.update(c);
readLength++;
if (readLength % (contentLength / 13) == 0)
{
printPercent(readLength, contentLength);
}
timeout = millis();
}
}
然后执行updateFromFS((函数，检查二进制文件是否都好，然后调用另一个函数performUpdate(updateBin，updateSize(；
void updateFromFS()
{
File updateBin = SPIFFS.open("/update.bin");
if (updateBin)
{
if (updateBin.isDirectory())
{
Serial.println("Directory error");
updateBin.close();
return;
}
size_t updateSize = updateBin.size();
if (updateSize > 0)
{
Serial.println("Starting update");
performUpdate(updateBin, updateSize);
}
else
{
Serial.println("Error, archivo vacío");
}
updateBin.close();
// whe finished remove the binary from sd card to indicate end of the process
//fs.remove("/update.bin");
}
else
{
Serial.println("no such binary");
}
}
在performUpdate(updateBin，updateSize(中，来自ArduinoUpdateLibrary的两个函数被调用(Update.beggin(updateSize(和Update.writeStream(updateSource((，这就是我无法再关注的地方。。。
void performUpdate(Stream &updateSource, size_t updateSize)
{
if (Update.begin(updateSize))
{
size_t written = Update.writeStream(updateSource);
if (written == updateSize)
{
Serial.println("Writes : " + String(written) + " successfully");
}
else
{
Serial.println("Written only : " + String(written) + "/" + String(updateSize) + ". Retry?");
}
if (Update.end())
{
Serial.println("OTA finished!");
if (Update.isFinished())
{
Serial.println("Restart ESP device!");
ESP.restart();
}
else
{
Serial.println("OTA not fiished");
}
}
else
{
Serial.println("Error occured #: " + String(Update.getError()));
}
}
else
{
Serial.println("Cannot beggin update");
}
}
我已找到此更新库源代码：https://github.com/espressif/arduino-esp32/blob/master/libraries/Update/src/Updater.cpp
但这似乎超出了我的知识范围，无法理解这段代码中到底发生了什么。
首先，我们只将1个变量传递给.begin方法，但函数原型需要的不仅仅是：
bool UpdateClass::begin(size_t size, int command, int ledPin, uint8_t ledOn, const char *label)
然后我试图理解函数Update.writeStream(updateSource(中发生了什么，但不能。。
如果有人能在这里发光，我将不胜感激！提前感谢。。。
算法将新固件(.bin(从云中下载到设备的本地内存，并使用UpdateClass库更改固件(如果你想我们用西班牙语说话，我可以看到西班牙语文本(
检查.h(只需要一个参数(
https://github.com/espressif/arduino-esp32/blob/master/libraries/Update/src/Update.h
/*
Call this to check the space needed for the update
Will return false if there is not enough space
*/
bool begin(size_t size=UPDATE_SIZE_UNKNOWN, int command = U_FLASH, int ledPin = -1, uint8_t ledOn = LOW, const char *label = NULL);
您可以使用OTAdrive库并将其用于OTA更新。请在此处查看esp32 gsm调制解调器OTA示例。