ESP8266 Switching firmware on the fly

Question

Can you help me out to understand if this is possible with ESP8266 / 32 ?

I have a main binary that i upload to the chip, let's call it A - that's done from arduino.

A starts to work, but communicates every couple of minutes with central server polling for a task.

If there is a task - let's call it B

A downloads it and stores it on SPIFFS.

Now what should happen is that A uploads it, reboots and B starts to work.

When B finishes it loads up again A and the circle closes - this process goes on forever.

Questions:

1) Is it possible that a stored on SPIFFS binary file can be uploaded to the chip? Like OTA does via www.

2) Can i somehow store A onto the SPIFFS, so that when B finishes i reupload A ?

Thanks for any input into this

• jsotola: why don't you have a single program that does both A and B?
• Majenko: Look at what ArduinoOTA does.
• PeeS: @Majenko - right, but i would then have to ask for firmware via WWW i don't speak to Web server, i download the binary from a dedicated grid computing system. So maybe you know if i can i download binary to SPIFFS and upload to chip other way than OTA?
• PeeS: @jsotola because B changes and is sent from a distributed system, has nothing to do with A. Binaries sent from distributed system will be different all the time.
• Majenko: Look at what ArduinoOTA does. I say again. Look at what it does. Don't use it. Just look at what it does.

Answer 1

The esp8266 Arduino package has 3 libraries for firmware update.

• ArduinoOTA for upload from Arduino IDE
• ESP8266HTTPUpdateServer for upload with web browser
• ESP8266httpUpdate library to check a web server for new version of the firmware

Answer 2

I think i've found an answer to my question here

https://www.esp8266.com/viewtopic.php?f=32&t=11324

#include <ESP8266WiFi.h>
#include <WiFiClient.h>
#include <ESP8266WebServer.h>
#include "FS.h"
void setup() {
 Serial.begin(115200);
 Serial.println();
 SPIFFS.begin();
 Dir dir = SPIFFS.openDir("/");
 pinMode(BUILTIN_LED, OUTPUT);
 digitalWrite(BUILTIN_LED, LOW);
 File file = SPIFFS.open("/blinkESP.bin", "r");
 uint32_t maxSketchSpace = (ESP.getFreeSketchSpace() - 0x1000) & 0xFFFFF000;
 if (!Update.begin(maxSketchSpace, U_FLASH)) { //start with max available size
 Update.printError(Serial);
 Serial.println("ERROR");
 }
 while (file.available()) {
 uint8_t ibuffer[128];
 file.read((uint8_t *)ibuffer, 128);
 Serial.println((char *)ibuffer);
 Update.write(ibuffer, sizeof(ibuffer));
 }
 Serial.print(Update.end(true));
 digitalWrite(BUILTIN_LED, HIGH);
 file.close();
}
void loop() {
}

Will give it a try and revert back to confirm if it answers my question.

• PeeS: Confirmed,works like a charm. Flashes firmware with a file from SPIFFS.