Is it possible to program ESP8266 from another microcontroller

avresp8266

I am using PL2303 USB to TTL adapter to program ESP8266, but I do not want to unplug it from system and plug it into PL2303 all the time. That's why I want to program it in system, with my AVR (the AVR is already connected to ESP8266 in the device that I intended to build).

What I want to achieve is that I just restart ESP8266 in flash mode (by hand. It is not a big deal, I can do it myself) and program it using AVR.

I could not ask a clearer question, because I couldn't think of any close solution. Please tolerate my confusion.

NOTE: Uploading a code to AVR which makes AVR act like USB to TTL adapter can be an option for me. That way, I can upload the code I wrote for ESP8266 through AVR.

NOTE 2: I am seeking for a help that eliminates the requirement of PL2303 and use directly AVR to program ESP.

Best Answer

I assume you are compiling and uploading (running esptool) on the PC. What I would try is:

Connect the serial lines from the PL2303 to the ESP8266 via two series resistors (start with trying 1k). Keep the AVR (which I assume is also connected to the serial pins of the ESP) in reset while downloading to the ESP. When the AVR comes out of reset it can 'take over' the seria lines because its output is much stronger than the 1k-impedance signal from the PL2303.

Notes - the AVR is connected directly to the ESP pins - you only need a resistor in the Rx line of the ESP, but why no put one in both - you might have to lower the esptool baudrate - you can do this in a more fancy way with a real switch, a digital switch, an analog switch, or even a relay

Related Solutions

Electronic – How to request “GET” from an ASP.NET website using ESP8266

You have an error in your HTTP request, the HTTP version should be uppercase (i.e. HTTP/1.1). Try your requests on a computer with telnet first. I get the following output:

$ telnet zgrdataserver.com.azhar.arvixe.com 80
Trying 23.91.112.247...
Connected to zgrdataserver.com.azhar.arvixe.com.
Escape character is '^]'.
GET /androidserver.aspx?param=esp8266 Http/1.1
HTTP/1.1 400 Bad Request
Content-Type: text/html; charset=us-ascii
Server: Microsoft-HTTPAPI/2.0
Date: Sun, 10 May 2015 18:54:39 GMT
Connection: close
Content-Length: 311

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN""http://www.w3.org/TR/html4/strict.dtd">
<HTML><HEAD><TITLE>Bad Request</TITLE>
<META HTTP-EQUIV="Content-Type" Content="text/html; charset=us-ascii"></HEAD>
<BODY><h2>Bad Request</h2>
<hr><p>HTTP Error 400. The request is badly formed.</p>
</BODY></HTML>
Connection closed by foreign host.

Notice that the server responds immediately after sending the first line. With a correct request I get:

$ telnet zgrdataserver.com.azhar.arvixe.com 80
Trying 23.91.112.247...
Connected to zgrdataserver.com.azhar.arvixe.com.
Escape character is '^]'.
GET /androidserver.aspx?param=esp8266 HTTP/1.1
Host: zgrdataserver.com.azhar.arvixe.com

HTTP/1.1 200 OK
Cache-Control: private
Content-Type: text/html; charset=utf-8
Server: Microsoft-IIS/8.0
X-AspNet-Version: 4.0.30319
X-Powered-By: ASP.NET
Date: Sun, 10 May 2015 18:55:53 GMT
Content-Length: 846

<br>
78.167.30.214<br>
asdf<br>
[...]

This is at least part of your problem.

As a suggestion, use HTTP/1.0 instead of HTTP/1.1. This prevents the server from sending chunked data and it will also automatically close the connection (without a Connection header in the request).

Electronic – arduino – How to program a microcontroller over another microcontroller

Basically your task will be to program a bootloader onto the one at the very end. That bootloader will need to accept specific commands via UART which causes it to reboot (watchdog?) and then enter the bootloader section. From the bootloader, it will again accept data which will overwrite your application area. After the update is done, boot to your application section (until you receive the command to update again).

Are you planning for a redesign at this point?

Best Answer

Related Solutions

Electronic – How to request “GET” from an ASP.NET website using ESP8266

Electronic – arduino – How to program a microcontroller over another microcontroller

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