How to send several data packets using AT+CIPSEND or AT+CIPSENDBUF?

akouz
Posts: 27
Joined: Tue May 10, 2016 1:10 pm

Re: How to send several data packets using AT+CIPSEND or AT+CIPSENDBUF?

Postby akouz » Wed Jul 27, 2016 2:31 pm

pratik wrote:Sorry, not able to reproduce the situation with v.0.60 either.


I monitor UART traffic from ESP8266 using Arduino serial monitor. ESP8266 is set to echo commands by ATE1. Here is a typical log:

+IPD,0,88:<...> AT+CIPSENDBUF=0,34
4,3

OK
> AT+CIPSENDBUF=0,38
busy s...

Recv 34 bytes

0,4,SEND OK

at this point microcontoller exits by time-out

At every step of data exchange with ESP8266 my microcontroller prints a debug message to USB. PC runs a test program, it decodes debug messages and adds time stamps to them. Combining those debug messages, time stamps with UART traffic above, overall picture looks as follows:

15:45:06 +IPD,0,88:<...> - microcontroller received a binary TCP message (it is a command) from PC, connection 0, 88 bytes
15:45:10 AT+CIPSENDBUF=0,34 - microcontroller prepared first reply to PC, 34 bytes, and starts CIPSENDBUF command
4,3

OK

15:45:10 > - microcontroller detects '>' symbol and start transmitting 34 bytes of binary data to ESP8266
15:45:10 - microcontroller finished transmitting 34 bytes of data to ESP8266, then it waits 10 ms before sending next command
15:45:10 AT+CIPSENDBUF=0,38 microcontroller prepared second reply to PC, 38 bytes, and starts CIPSENDBUF command
15:45:20 - microcontroller reports time-out, there is no symbol '>' for the last 10 sec

What I am doing wrong?

Can you describe your set-up? Can I reproduce your set-up here? What program do you use to communicate to the UART of ESP8266? Is it a PC program or a microcontroller?

akouz
Posts: 27
Joined: Tue May 10, 2016 1:10 pm

Re: How to send several data packets using AT+CIPSEND or AT+CIPSENDBUF?

Postby akouz » Thu Jul 28, 2016 1:07 pm

pratik wrote:The CIPSENDBUF command responds very fast and also transmits immediately. My laptop, connected to the router is running XAMPP server.
I tried the same with by connecting to Google, sending a GET request in packet sizes of 24 bytes using multiple SENDBUF commands. Works just find, maximum delay I got anywhere was less than 200 ms. Local network latency is way faster.


Could you please provide a log of AT commands you sent to ESP8266 while sending multiple AT+CIPSENDBUF commands?

karan_k1110
Posts: 1
Joined: Mon Jun 17, 2019 3:59 pm

Re: How to send several data packets using AT+CIPSEND or AT+CIPSENDBUF?

Postby karan_k1110 » Mon Jun 17, 2019 4:05 pm

I have to send an image that is 11KB, I can't send it using cpisend because it only allows 2KB to be sent. So shall I use CPISEND command multiple times?

Her Mary
Posts: 411
Joined: Mon Oct 27, 2014 11:09 am

Re: How to send several data packets using AT+CIPSEND or AT+CIPSENDBUF?

Postby Her Mary » Wed Jun 26, 2019 10:43 am

Why don't you use the UART-WiFi passthrough mode?

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