💾 Archived View for floppy.p1x.in › micro › article › fun-with-at.gmi captured on 2023-03-20 at 17:53:14. Gemini links have been rewritten to link to archived content
⬅️ Previous capture (2023-01-29)
-=-=-=-=-=-=-
Written on Jan 29, 2022
You need any RS323 communication tool. I recommend Termite (Windows) or Hercules SETUP Utility (Windows). Termite is easier to use at first. For more complex interactions like setting up a web server or sending/receiving data from the web, Hercules becomes more useful.
Easy Termite version 3.4 (Setup, 332 KiB).
Advanced Hercules version3-2-8 (Binary, 38.3 KiB)
For now, I will use Termite. Out-of-the-box settings are OK. Port and Baud rate should be detected automatically. Just turn off the local echo (it repeats each sent command).
Try AT and AT+GMR to confirm everything is working.
The most basic and important command is AT (empty, without any parameters). It is kind of saying "Hello" to the chip. If everything is working fine it should return OK.
> AT OK
Most of the commands are ended by an OK string. This indicates the end of the message from the ESP.
Another useful command is GMR which returns all the information about the installed firmware.
> AT+GMR AT version:1.6.2.0(Apr 13 2018 11:10:59) SDK version:2.2.1(6ab97e9) compile time:Jun 7 2018 19:34:26 Bin version(Wroom 02):1.6.2 OK
You can restart the board by simply toggling the power (re-plug USB). To actually see the boot messages it's better to just use the reset command RST.
> AT+RST
OK
WIFI DISCONNECT
ets Jan 8 2013,rst cause:2, boot mode:(3,7)
load 0x40100000, len 2408, room 16
tail 8
chksum 0xe5
load 0x3ffe8000, len 776, room 0
tail 8
chksum 0x84
load 0x3ffe8310, len 632, room 0
tail 8
chksum 0xd8
csum 0xd8
2nd boot version : 1.6
SPI Speed : 40MHz
SPI Mode : DOUT
SPI Flash Size & Map: 4Mbit(256KB+256KB)
jump to run user1 @ 1000
„ă[03]ě[1B]Ă'ä’{Ăón<ä[04]$Śäl`[03][1C]b“[1B][03][04]ź|[02]{’[03]lÜnŕ[04]oâ[00]dl [03]Śâs“l„l[1B]Ä[0C][04]ěl`[03]„ă;›děd[12]Ś[04][0C][0C]d`[03]ŚăsŰl[0C]Źž[00]„[0C][0C]dl [03]s$ŹĂslŚžă„c[04]Ś„c[1C]|d[0C]cŹŕ[04][13]ä‡ăălcäň'ç€[13]noă[10][03][0C][03]Śdű|[02][04]äÇ„[0C]d[04][0C]děŚd‡|ě$[0C]Ź[07]dŔ[03]gü[00]ÄßăŚ#[04]$läŚÇ[1B][0C]#[04][03][03]ŚßăŚb[04]l[0C]„c[1C]rl;l
ready
WIFI CONNECTED
WIFI GOT IP
Use SYSRAM - System Random Access Memory - with "?" at the end to prompt for the value.
> AT+SYSRAM? AT+SYSRAM? +SYSRAM:32968 OK
Using CWMODE you can check (?) or change (=N) the WiFi mode as a client (1), AP(2), or both(3):
AT+CWMODE? +CWMODE:1 OK
AT+CWMODE=2 OK
Check (?) and change (="NAME") hostname:
> AT+CWHOSTNAME? AT+CWHOSTNAME? +CWHOSTNAME:ESP_21D811 OK
> AT+CWHOSTNAME="ESP-01" OK
Enable DHCP for both SoftAP and Station modes.
> AT+CWDHCP=1,1
List Acces Points
The CWLAP - List AccessPoints will print all visible wifi networks (on 2.4Ghz spectrum.)
> AT+CWLAP AT+CWLAP +CWLAP:(3,"Orange_Swiatlowod_4DD0",-68,"d4:f8:29:92:4d:d0",1,70,0,4,4,7,1) +CWLAP:(4,"rybki",-87,"54:e6:fc:ea:10:5a",1,78,0,5,3,3,0) +CWLAP:(4,"P1X_2.4GHz",-53,"58:ef:68:b9:77:a9",6,83,0,4,3,7,1) +CWLAP:(0,"ESP_0D3294",-57,"4a:3f:da:0d:32:94",6,103,0,0,0,3,0) +CWLAP:(4,"komster.net-522515704",-73,"90:9a:4a:94:0d:36",9,93,0,5,3,7,1) +CWLAP:(4,"INEA-4236_2.4G",-85,"30:cc:21:1c:a5:a3",9,32767,0,5,3,6,0) OK
Connect to your network using the CWJAP command - Join AccessPoint. Provide name and password.
> AT+CWJAP="P1X_2.4GHz","password" AT+CWJAP="P1X_2.4GHz","password" WIFI CONNECTED WIFI GOT IP OK
Get the microcontroller IP using the CIFSR command.
> AT+CIFSR +CIFSR:STAIP,"192.168.1.175" +CIFSR:STAMAC,"08:31:c8:21:d8:11" OK
If you need to get a static IP set it using CIPSTA where the first parameter is IP, the second is DNS and the last is a mask.
> AT+CIPSTA="192.168.1.123","192.168.1.1","255.255.255.0"
Simple as CWQAP - Quit AccessPoint.
> AT+CWQAP OK
You don't need Apache anymore! ;)
> AT+CIPMUX=1 > AT+CIPSERVER=1,80
AT+CIPSEND=0,12 <h1>P1X</h1> AT+CIPCLOSE=0
> AT+CIPSERVER=0 > AT+RST
Send more data in packets.
> AT+CIPSEND=0,12 <h1>P1X</h1> > AT+CIPSEND=0,41 <p>Welcome to the AT learning session</p> > AT+CIPCLOSE=0
> AT+CIPMUX=1 OK > AT+CIPSERVER=1,80 no change OK
Now go to TCP Client and connect to the microcontroller IP (hint: use AT+CIFSR to get it.)
After that you should see a new connection in the Serial tab:
0,CONNECT
The first number is the ID of the client. Each connected client gets a different ID. To send any message/data to it you will need to specify that ID.
CIPSEND command takes two arguments:
To send "hello" count the letters (5 in that case) and use them in the command:
AT+CIPSEND=0,5 OK > hello Recv 5 bytes SEND OK
It will prompt ">" for the message. It will not be visible while typing. After you fill up 5 bytes it will send them to the client. Go to the TCP Client tab and see if your message arrives.
Now write whatever you want in the input below and hit send.
Back to the ESP tab (Serial), you should see that client 0 sends, 9 bytes that represent the "whats up?" string.