Hi, I posted this on the espressif/esp8266_at github issues but it has received no response so I repost it here ...
I am using at_v0.20_14_11_28 to contact a NTP server via UDP. If I use the IP address it works ok as below
AT+CIPMUX=0
AT+CIPSTART="UDP","134.130.4.17",123
AT+CIPSEND=48
(NTP data Recieved OK)
However if I use a domain name, the DNS lookup works correctly but the following AT+CIPSEND hangs with no > data prompt
AT+CIPMUX=0
AT+CIPSTART="UDP","pool.ntp.org",123
AT+CIPSTATUS - returns +CIPSTATUS:0,"UDP","217.114.59.3",123,25349,0 (which is correct at the time)
AT+CIPSEND=48 - hangs with no > data prompt
I have looked at the source code for AT+CIPSTART in 'at_ipCmd.c' and i see that for a UDP start with IP address
espconn_create is called at line 818 (TCP calls espconn_connect). However if a DNS lookup is required, the callback function
at_dns_found calls espconn_connect for both TCP and UDP !
I think at_dns_found should call espconn_create for UDP ?
Also at line 731 "ALREAY CONNECT\r\n" should be "ALREADY CONNECT\r\n" or even better english is "ALREADY CONNECTED\r\n"
I hope you can correct this problem. I cannot build the code myself yet. If you like to post new user.bin file I can test it out
Congratulations on a great device !
Thankyou
Dennis Tricker
UK
AT+CIPSTART bug when using UDP and DNS lookup
Re: AT+CIPSTART bug when using UDP and DNS lookup
Postby ESP_Faye » Tue Jan 06, 2015 3:36 pm


I have replicated your problem, we are working on it.
Thanks for the bug report.
Re: AT+CIPSTART bug when using UDP and DNS lookup
Postby ESP_Faye » Thu Feb 05, 2015 4:23 pm
The problem you mentioned has been resolved in AT_v0.21_on_sdk_v0.9.5
please have a try and feel free to let us know if you have any question ~
http://bbs.espressif.com/viewtopic.php?f=5&t=154
Thanks for your interest in ESP8266 !
please have a try and feel free to let us know if you have any question ~
http://bbs.espressif.com/viewtopic.php?f=5&t=154
Thanks for your interest in ESP8266 !
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