Sending GCODE to Marlin ESP32 from ESP32C3 online

[khbilen]

I have built a laser cutter using tinyBee as the main board running Marlin V2, with ESP32 on board with wifi support.
I can run the cutter using ESP3D on my Andoid phone from the web GUI. No problem. I can use gcode files to do full batch work, I can navigate using the virtual joystik, or send single GCODE commands from the command input area. They are all OK.

Now, I want to send GCODE line by line from ESP32C3 to Marlin online.

I can connect to my local Wifi.
But then I do not know how to send individual commands without a web page. Or how to use the command line input from a, lets say virtual ESP3D page loaded on ESP32C3 when dialed marlin IP??

[luc-github]

I do not understand why do you want to connect an espc3 to the tinybee ? tinybee already have wifi and everything
You just connecte your tinybee using wifi by telnet from you PC or even your phone

[khbilen]

I will have an application running on ESP32C3 which will create GCODE in realtime, and then request marlin to execute it. I am not trying to replace ESP on tiny bee, trying to talk to it.

[luc-github]

then connect using telnet (actually raw tcp) but you need esp3dlib V3 - the current esp3dlib in Marlin release do not have telnet support

[luc-github]

you can have a look to commands and docs here : https://esp3d.io/ESP3DLib/

https://esp3d.io/ESP3D/Version_3.X/documentation/api/
https://esp3d.io/ESP3DLib/Version_3.X/documentation/api/

[khbilen]

I looked at esp3dlib but could not quite get how it works.

[khbilen]

let me have some more look, then...

[khbilen]

Actually, all I need is what the SEND button does on the Web GUI after I enter a single command.
From the source code, I can see you are using a function called SendCustomCommand(), which calls SendGET... I know I need to use GET PUT somehow, but I need the handers' names. etc...

[luc-github]

not that simple - command go by http but response come back using websocket

when using raw tcp/telnet you have permanent both way communication

[luc-github]

esp3dlib V1 should follow same handlers as esp3d 2.x https://esp3d.io/ESP3D/Version_2.1.X/documentation/api/

[khbilen]

OK. I just exected

http://192.168.1.23/command?&&commandText=%22M115%22

successfuly.

I guess I can move on.

Thanks.

[luc-github]

this one is better http://192.168.1.23/command?commandText=M115

[khbilen]

Well, everything looked fine as long as I worked on the browser on my PC, but when I loaded the same commands on theESP32C3 nothing seems to happen. I think that is due to communication format differences between the browser and the ESP32 output.

On the browser input line, plain command works fine:

192.168.1.23/command?commandText=G1X300F3500

on the ESP3d app GUI on the browser, at top right menu, it says UI 2.1.3b0. So I should be looking at and using V2 documentation, I think.

The document says, I should be using [ESPXXX] commands to talk to ESP3D otherwise they are ignored.

I tested most of those commands, first on the browser line, and then within the ESP32 script.

On the browser input, ESP100, 102, 110, 111, and similar commands work fine. I get response on the browser page, fine.

But nothing happens when I use them within the script. Normally I should be using them with GET prefix I believe. I tried following input formats

...
client connected.
...
client.println("GET /command?commandText=G1X300F3500");
or
client.println("/command?commandText=G1X300F3500");
nothing happens.

client.println("GET /[ESP111]");
or
client.println("/command?commandText=[ESP111]");
or
client.println("GET /command?commandText=[ESP111]");

nothing happens

Either I am all wrong with those formats, or ESP3D ignores them.

For V2, there is [ESP500] command which allows for sending gcode to marlin.
That does not work even on the browser, and it says invalid command. In V3 there is no such command, which means not possible to ask for gcode execution?!

Are there any working samples for V2 or V3 where I can see the correct usage format?

[luc-github]

ESP3DLib v1 is based on ESP3D V2.x but do not have all features / commands
on webUI type [ESP0] to know what command is available, or chack source here : https://github.com/luc-github/ESP3DLib/blob/master/src/command.cpp#L107-L133

I do not know how you communicate with ESP3DLib sorry but I think that is you issue, I have tried curl tool and it is working, I had to encode the bracket because curl use them

C:\Users\luc>curl -v http://192.168.1.104/command?cmd=%5BESP420%5D
*   Trying 192.168.1.104:80...
* Established connection to 192.168.1.104 (192.168.1.104 port 80) from 192.168.1.109 port 40930
* using HTTP/1.x
> GET /command?cmd=%5BESP420%5D HTTP/1.1
> Host: 192.168.1.104
> User-Agent: curl/8.16.0
> Accept: */*
>
* Request completely sent off
< HTTP/1.1 200 OK
< Content-Type:
< User-Agent: ESP3D-WebServer/1.0 (ESP82XX; Firmware/3.0.1; Platform/arduino; Embedded; http://www.esp3d.io)
< Host: Host: http://192.168.1.104
< Cache-Control: no-cache
< Accept-Ranges: none
< Transfer-Encoding: chunked
< Connection: keep-alive
< Keep-Alive: timeout=2000
<
Configuration:
chip id: 58352
CPU Freq: 160Mhz
free mem: 19.98 KB
FW arch: ESP82XX
SDK: 2.2.2-dev(38a443e)
Arduino: 3.1.1
flash size: 4.00 MB
size for update: 1023.00 KB
FS type: LittleFS
FS usage: 104.00 KB/1.98 MB
baud: 115200
sleep mode: none
wifi: ON
hostname: esp3d
SSDP: ON
MDNS: ON
HTTP port: 80
Telnet port: 23
wifi mode: sta
SSID: Luc-Lab
signal: 100%
phy mode: 11g
channel: 4
ip mode: dhcp
ip: 192.168.1.104
gw: 192.168.1.1
msk: 255.255.255.0
DNS: 192.168.1.1
ap: OFF
ntp: OFF
serial: ON (UART0)
authentication: OFF
notification: ON (none)
targetfw: unknown
FW ver: 3.0.1
ok
* Connection #0 to host 192.168.1.104:80 left intact

so I think your issue is in your code

the command for GCODE is same, the ESP500 is to have checksum in the command but is not what you want

[khbilen]

I do not have curl. I simply use the input line of the boıwser to enter the command. When I enter the command: 192.168.1.23/command?commandText=[ESP] i.e, asking for the available commands list on this installation, I get the following: [List of ESP3D commands] [ESP] - display this help [ESP100](SSID) - display/set STA SSID [ESP101](Password) - set STA password [ESP102](Mode) - display/set STA IP mode (DHCP/STATIC) [ESP103](IP=xxxx MSK=xxxx GW=xxxx) - display/set STA IP/Mask/GW [ESP105](SSID) - display/set AP SSID [ESP106](Password) - set AP password [ESP107](IP) - display/set AP IP [ESP108](Chanel) - display/set AP chanel [ESP110](State) - display/set radio state which can be STA, AP, OFF [ESP111]display current IP [ESP112](Hostname) - display/set Hostname [ESP120](State) - display/set HTTP state which can be ON, OFF [ESP121](Port) - display/set HTTP port [ESP200] - display SD Card Status [ESP400] - display ESP3D settings in JSON [ESP401]P=(position) T=(type) V=(value) - Set specific setting [ESP410] - display available AP list (limited to 30) in JSON [ESP420] - display ESP3D current status [ESP444](Cmd) - set ESP3D state (RESET/RESTART) [ESP710]FORMAT - Format ESP Filesystem [ESP800] - display FW Informations So, yes I can enter command [ESP420] as you have done, but of course that gives me current status info, only. Unfortunately I can not see [ESP500] in the list, and no mentioning of gcode entry. That means there is no way out with this installation and using [ESPXXX] commands. The only remaining option is to execute "http://192.168.1.23/ /command?commandText=G1X300F3500", ie the gcode directly from within the esp/arduino script.I should be able to get the same result as if I type this in at the browser input line. I tried HTTPClient with WiFi Server, but no success. There are indirect ways which are not useful. I can create some dummy web page, and upon loading execute "window.locate.href= http://192.168.1.23/ /command?commandText=G1X300F3500" statement, but it needs manual launch which makes it useless. Any idea? 21 Oca 2026 Çar 13:17 tarihinde Luc ***@***.***> şunu yazdı:

…

ESP3DLib v1 is based on ESP3D V2.x but do not have all features / commands on webUI type [ESP0] to know what command is available, or chack source here : https://github.com/luc-github/ESP3DLib/blob/master/src/command.cpp#L107-L133 I do not know how you communicate with ESP3DLib sorry but I think that is you issue, I have tried curl tool and it is working, I had to encode the bracket because curl use them C:\Users\luc>curl -v http://192.168.1.104/command?cmd=%5BESP420%5D * Trying 192.168.1.104:80... * Established connection to 192.168.1.104 (192.168.1.104 port 80) from 192.168.1.109 port 40930 * using HTTP/1.x > GET /command?cmd=%5BESP420%5D HTTP/1.1 > Host: 192.168.1.104 > User-Agent: curl/8.16.0 > Accept: */* > * Request completely sent off < HTTP/1.1 200 OK < Content-Type: < User-Agent: ESP3D-WebServer/1.0 (ESP82XX; Firmware/3.0.1; Platform/arduino; Embedded; http://www.esp3d.io) < Host: Host: http://192.168.1.104 < Cache-Control: no-cache < Accept-Ranges: none < Transfer-Encoding: chunked < Connection: keep-alive < Keep-Alive: timeout=2000 < Configuration: chip id: 58352 CPU Freq: 160Mhz free mem: 19.98 KB FW arch: ESP82XX SDK: 2.2.2-dev(38a443e) Arduino: 3.1.1 flash size: 4.00 MB size for update: 1023.00 KB FS type: LittleFS FS usage: 104.00 KB/1.98 MB baud: 115200 sleep mode: none wifi: ON hostname: esp3d SSDP: ON MDNS: ON HTTP port: 80 Telnet port: 23 wifi mode: sta SSID: Luc-Lab signal: 100% phy mode: 11g channel: 4 ip mode: dhcp ip: 192.168.1.104 gw: 192.168.1.1 msk: 255.255.255.0 DNS: 192.168.1.1 ap: OFF ntp: OFF serial: ON (UART0) authentication: OFF notification: ON (none) targetfw: unknown FW ver: 3.0.1 ok * Connection #0 to host 192.168.1.104:80 left intact so I think your issue is in your code — Reply to this email directly, view it on GitHub <#1117 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ACWWAZVFAHARFLW4J4CJJK34H5G4BAVCNFSM6AAAAACSIGJLQSVHI2DSMVQWIX3LMV43URDJONRXK43TNFXW4Q3PNVWWK3TUHMYTKNJVHAZDIOI> . You are receiving this because you authored the thread.Message ID: ***@***.***>

[luc-github]

I already told you do not need to use [ESP500] it is not what you need
I showed you that curl is working so it is not linked to using browser and command line queries are possible
you showed that you have no idea of what http protocol is by guessing how to send http queries
I told you the issue is in your code not the way to access, which is http with esp3dlib V1

if you really did your home work you should be able to use http client and validate it work on any website before saying it does not work on esp3dlib to identify your issue, you do not need a dummy web page - just coding the right thing properly

And yes httpclient is the easiest way to achieve what you want

[khbilen]

OK, This code works fine, without using [ESP500] but sending GCODE directly. #include <Arduino.h> #include <WiFi.h> #include <WiFiMulti.h> #include <HTTPClient.h> WiFiMulti wifiMulti; void setup() { Serial.begin(115200); Serial.println(); Serial.println(); Serial.println(); for (uint8_t t = 4; t > 0; t--) { Serial.printf("[SETUP] WAIT %d...\n", t); Serial.flush(); delay(1000); } wifiMulti.addAP("SUPERONLINE-WiFi_2111", "XXYHUY7WUTKF"); } void loop() { // wait for WiFi connection if ((wifiMulti.run() == WL_CONNECTED)) { HTTPClient http; Serial.print("[HTTP] begin...\n"); // configure server and url //http.begin("https://dummyjson.com/products"); http.begin("192.168.1.23", 80, "/command?commandText=G1X300F3500"); Serial.print("[HTTP] GET...\n"); // start connection and send HTTP header int httpCode = http.GET(); if (httpCode > 0) { // HTTP header has been send and Server response header has been handled Serial.printf("[HTTP] GET... code: %d\n", httpCode); // file found at server if (httpCode == HTTP_CODE_OK) { // get length of document (is -1 when Server sends no Content-Length header) int len = http.getSize(); // create buffer for read uint8_t buff[128] = {0}; // get tcp stream NetworkClient *stream = http.getStreamPtr(); // read all data from server while (http.connected() && (len > 0 || len == -1)) { // get available data size size_t size = stream->available(); if (size) { // read up to 128 byte int c = stream->readBytes(buff, ((size > sizeof(buff)) ? sizeof(buff) : size)); // write it to Serial Serial.write(buff, c); if (len > 0) { len -= c; } } delay(1); } Serial.println(); Serial.print("[HTTP] connection closed or file end.\n"); } } else { Serial.printf("[HTTP] GET... failed, error: %s\n", http.errorToString(httpCode).c_str()); } http.end(); } delay(10000); } Thanks Kadir Luc ***@***.***>, 22 Oca 2026 Per, 01:15 tarihinde şunu yazdı:

…

I already told you do not need to use [ESP500] it is not what you need I showed you that curl is working so it is not linked to using browser and command line queries are possible you showed that you have no idea of what http protocol is by guessing how to send http queries I told you the issue is in your code not the way to access, which is http with esp3dlib V1 if you really did your home work you should be able to use http client and validate it work on any website before saying it does not work on esp3dlib to identify your issue, you do not need a dummy web page - just coding the right thing properly — Reply to this email directly, view it on GitHub <#1117 (reply in thread)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ACWWAZS4C2HUJDT2REX42734IACBPAVCNFSM6AAAAACSIGJLQSVHI2DSMVQWIX3LMV43URDJONRXK43TNFXW4Q3PNVWWK3TUHMYTKNJWGQ4DMOI> . You are receiving this because you authored the thread.Message ID: ***@***.***>