准备工作
- 配置好开发环境,本文是基于
VSCODE + PlatformIO
- 一个可用于联网的WiFi
- 编译一个.bin固件升级程序,并上传得到一个http网址。
首先编写一个程序,每隔1s打印hello world!
,并生成.bin升级固件。关于如何编译生成.bin升级固件,详见附录。
#include <Arduino.h>
void setup()
{
// put your setup code here, to run once:
Serial.begin(115200);
}
void loop()
{
// put your main code here, to run repeatedly:
Serial.println("hello world!");
delay(1000);
}
空中升级OTA代码说明
程序流程讲解:开机-->等待联网-->成功联网-->升级。
- 引入头文件
#include <WiFi.h>
#include <HTTPUpdate.h>
- 根据实际添加相关变量:wifi的名称及密码、远程升级固件的地址
/**********根据实际修改**********/
const char *wifi_ssid = "your wifi ssid"; // WIFI名称,区分大小写,不要写错
const char *wifi_password = "your wifi password "; // WIFI密码
//远程固件链接,只支持http
const char *ota_url = "http://media-1251347578.cos.ap-beijing.myqcloud.com/firmware.bin";
/**********根据实际修改**********/
- 连接wifi
WiFi.begin(wifi_ssid, wifi_password); //连接wifi
while (WiFi.status() != WL_CONNECTED)
{ //等待连接wifi
delay(500);
Serial.print(".");
}
- 远程固件升级
/**
* @brief 固件升级函数,通过http请求获取远程固件,实现升级
*
* @param update_url 待升级远程固件bin文件的地址
* @return t_httpUpdate_return 升级最终状态
*/
t_httpUpdate_return updateBin(const char *update_url)
{
WiFiClient UpdateClient;
t_httpUpdate_return ret = httpUpdate.update(UpdateClient, update_url);
return ret;
}
- 【可选】升级过程回调函数,用于提示升级过程(失败、成功、升级进度等)
//当升级开始时,打印日志
void update_started()
{
Serial.println("CALLBACK: HTTP update process started");
}
//当升级结束时,打印日志
void update_finished()
{
Serial.println("CALLBACK: HTTP update process finished");
}
//当升级中,打印日志
void update_progress(int cur, int total)
{
Serial.printf("CALLBACK: HTTP update process at %d of %d bytes[%.1f%%]...\n", cur, total, cur * 100.0 / total);
}
//当升级失败时,打印日志
void update_error(int err)
{
Serial.printf("CALLBACK: HTTP update fatal error code %d\n", err);
}
/**
* @brief 固件升级函数,通过http请求获取远程固件,实现升级
*
* @param update_url 待升级远程固件bin文件的地址
* @return t_httpUpdate_return 升级最终状态
*/
t_httpUpdate_return updateBin(const char *update_url)
{
Serial.println("start update");
WiFiClient UpdateClient;
httpUpdate.onStart(update_started); //当升级开始时
httpUpdate.onEnd(update_finished); //当升级结束时
httpUpdate.onProgress(update_progress); //当升级中
httpUpdate.onError(update_error); //当升级失败时
t_httpUpdate_return ret = httpUpdate.update(UpdateClient, update_url);
return ret;
}
运行程序后,ESP32成功连接wifi即开始远程固件升级。
Connection WIFI..........
start update
CALLBACK: HTTP update process started
CALLBACK: HTTP update process at 0 of 232976 bytes[0.0%]...
CALLBACK: HTTP update process at 0 of 232976 bytes[0.0%]...
CALLBACK: HTTP update process at 4096 of 232976 bytes[1.8%]...
CALLBACK: HTTP update process at 8192 of 232976 bytes[3.5%]...
CALLBACK: HTTP update process at 12288 of 232976 bytes[5.3%]...
CALLBACK: HTTP update process at 16384 of 232976 bytes[7.0%]...
CALLBACK: HTTP update process at 20480 of 232976 bytes[8.8%]...
CALLBACK: HTTP update process at 24576 of 232976 bytes[10.5%]...
CALLBACK: HTTP update process at 28672 of 232976 bytes[12.3%]...
CALLBACK: HTTP update process at 32768 of 232976 bytes[14.1%]...
CALLBACK: HTTP update process at 36864 of 232976 bytes[15.8%]...
CALLBACK: HTTP update process at 40960 of 232976 bytes[17.6%]...
CALLBACK: HTTP update process at 45056 of 232976 bytes[19.3%]...
CALLBACK: HTTP update process at 49152 of 232976 bytes[21.1%]...
CALLBACK: HTTP update process at 53248 of 232976 bytes[22.9%]...
CALLBACK: HTTP update process at 57344 of 232976 bytes[24.6%]...
CALLBACK: HTTP update process at 61440 of 232976 bytes[26.4%]...
CALLBACK: HTTP update process at 65536 of 232976 bytes[28.1%]...
CALLBACK: HTTP update process at 69632 of 232976 bytes[29.9%]...
CALLBACK: HTTP update process at 73728 of 232976 bytes[31.6%]...
CALLBACK: HTTP update process at 77824 of 232976 bytes[33.4%]...
CALLBACK: HTTP update process at 81920 of 232976 bytes[35.2%]...
CALLBACK: HTTP update process at 86016 of 232976 bytes[36.9%]...
CALLBACK: HTTP update process at 90112 of 232976 bytes[38.7%]...
CALLBACK: HTTP update process at 94208 of 232976 bytes[40.4%]...
CALLBACK: HTTP update process at 98304 of 232976 bytes[42.2%]...
CALLBACK: HTTP update process at 102400 of 232976 bytes[44.0%]...
CALLBACK: HTTP update process at 106496 of 232976 bytes[45.7%]...
CALLBACK: HTTP update process at 110592 of 232976 bytes[47.5%]...
CALLBACK: HTTP update process at 114688 of 232976 bytes[49.2%]...
CALLBACK: HTTP update process at 118784 of 232976 bytes[51.0%]...
CALLBACK: HTTP update process at 122880 of 232976 bytes[52.7%]...
CALLBACK: HTTP update process at 126976 of 232976 bytes[54.5%]...
CALLBACK: HTTP update process at 131072 of 232976 bytes[56.3%]...
CALLBACK: HTTP update process at 135168 of 232976 bytes[58.0%]...
CALLBACK: HTTP update process at 139264 of 232976 bytes[59.8%]...
CALLBACK: HTTP update process at 143360 of 232976 bytes[61.5%]...
CALLBACK: HTTP update process at 147456 of 232976 bytes[63.3%]...
CALLBACK: HTTP update process at 151552 of 232976 bytes[65.1%]...
CALLBACK: HTTP update process at 155648 of 232976 bytes[66.8%]...
CALLBACK: HTTP update process at 159744 of 232976 bytes[68.6%]...
CALLBACK: HTTP update process at 163840 of 232976 bytes[70.3%]...
CALLBACK: HTTP update process at 167936 of 232976 bytes[72.1%]...
CALLBACK: HTTP update process at 172032 of 232976 bytes[73.8%]...
CALLBACK: HTTP update process at 176128 of 232976 bytes[75.6%]...
CALLBACK: HTTP update process at 180224 of 232976 bytes[77.4%]...
CALLBACK: HTTP update process at 184320 of 232976 bytes[79.1%]...
CALLBACK: HTTP update process at 188416 of 232976 bytes[80.9%]...
CALLBACK: HTTP update process at 192512 of 232976 bytes[82.6%]...
CALLBACK: HTTP update process at 196608 of 232976 bytes[84.4%]...
CALLBACK: HTTP update process at 200704 of 232976 bytes[86.1%].
..
CALLBACK: HTTP update process at 204800 of 232976 bytes[87.9%]...
CALLBACK: HTTP update process at 208896 of 232976 bytes[89.7%]...
CALLBACK: HTTP update process at 212992 of 232976 bytes[91.4%]...
CALLBACK: HTTP update process at 217088 of 232976 bytes[93.2%]...
CALLBACK: HTTP update process at 221184 of 232976 bytes[94.9%]...
CALLBACK: HTTP update process at 225280 of 232976 bytes[96.7%]...
CALLBACK: HTTP update process at 229376 of 232976 bytes[98.5%]...
CALLBACK: HTTP update process at 232976 of 232976 bytes[100.0%]...
CALLBACK: HTTP update process at 232976 of 232976 bytes[100.0%]...
CALLBACK: HTTP update process finished
升级完毕会运行升级的程序
hello world!
hello world!
hello world!
hello world!
hello world!
hello world!
hello world!
hello world!
注意事项
1. 远程固件链接需为http协议
使用OTA升级,远程固件链接不支持https协议。如果使用了https,将升级失败。
例如,将远程固件链接更换为https协议
//远程固件链接
const char *ota_url = "https://media-1251347578.cos.ap-beijing.myqcloud.com/firmware.bin";
ESP运行时,进行OTA升级,会返回400失败。
Connection WIFI..........
start update
[ 6077][E][HTTPUpdate.cpp:380] handleUpdate(): HTTP Code is (400)
[update] Update failed.
2. 远程链接确保为ESP32编译后固件
如果远程固件地址为非正常编译后bin文件,OTA升级会有校验,升级失败。
Connection WIFI.....
start update
CALLBACK: HTTP update process started
[ 4281][E][HTTPUpdate.cpp:323] handleUpdate(): Magic header does not start with 0xE9
[update] Update failed.
从中串口打印的提示信息可以看出,OTA是校验远程链接文件开头是不是0xE9。使用winhex打开编译后的固件文件,确实可以看到开始是0xE9。
附录1 ESP32空中升级OTA完整代码
完整代码可在GitHub下载:canhetingsky/ESP32_DEV/ESP32_OTA
#include <WiFi.h>
#include <HTTPUpdate.h>
/**********根据实际修改**********/
const char *wifi_ssid = "your wifi ssid"; // WIFI名称,区分大小写,不要写错
const char *wifi_password = "your wifi password "; // WIFI密码
//远程固件链接,只支持http
const char *ota_url = "http://media-1251347578.cos.ap-beijing.myqcloud.com/firmware.bin";
/**********根据实际修改**********/
//当升级开始时,打印日志
void update_started()
{
Serial.println("CALLBACK: HTTP update process started");
}
//当升级结束时,打印日志
void update_finished()
{
Serial.println("CALLBACK: HTTP update process finished");
}
//当升级中,打印日志
void update_progress(int cur, int total)
{
Serial.printf("CALLBACK: HTTP update process at %d of %d bytes[%.1f%%]...\n", cur, total, cur * 100.0 / total);
}
//当升级失败时,打印日志
void update_error(int err)
{
Serial.printf("CALLBACK: HTTP update fatal error code %d\n", err);
}
/**
* @brief 固件升级函数,通过http请求获取远程固件,实现升级
*
* @param update_url 待升级远程固件bin文件的地址
* @return t_httpUpdate_return 升级最终状态
*/
t_httpUpdate_return updateBin(const char *update_url)
{
Serial.println("start update");
WiFiClient UpdateClient;
httpUpdate.onStart(update_started); //当升级开始时
httpUpdate.onEnd(update_finished); //当升级结束时
httpUpdate.onProgress(update_progress); //当升级中
httpUpdate.onError(update_error); //当升级失败时
t_httpUpdate_return ret = httpUpdate.update(UpdateClient, update_url);
return ret;
}
void setup()
{
Serial.begin(115200); //波特率115200
Serial.print("Connection WIFI");
WiFi.begin(wifi_ssid, wifi_password); //连接wifi
while (WiFi.status() != WL_CONNECTED)
{ //等待连接wifi
delay(500);
Serial.print(".");
}
Serial.println("");
t_httpUpdate_return ret = updateBin(ota_url); //开始升级
switch (ret)
{
case HTTP_UPDATE_FAILED: //当升级失败
Serial.println("[update] Update failed.");
break;
case HTTP_UPDATE_NO_UPDATES: //当无升级
Serial.println("[update] Update no Update.");
break;
case HTTP_UPDATE_OK: //当升级成功
Serial.println("[update] Update ok.");
break;
}
}
void loop()
{
}
附录2 如何编译生成.bin升级固件
PlatformIO编译生成.bin固件
在项目文件夹下的.pio\build\esp32dev
,可以找到编译后固件firmware.bin
。
Arduino IDE编译生成.bin固件
使用Arduino IDE开发ESP32,需要配置好开发环境。
在Arduino IDE中,依次点击「项目」-「导出已编译的二进制文件」,编译完毕,即可在项目文件夹下看到生成的的.bin
文件。