Datasheet

Flyport Wi-Fi and Ethernet Programmer's guide framework 2.3 (rev 1.0) www.openpicus.com

SNTP Client

SNTP service is a Simple Network Time Protocol, a simplified version of NTP protocol for embedded

devices. Using this feature, Flyport can download from the internet network very precise time

information from dedicated time servers.

Using this feature, Flyport can always be in sync with “real world” time. Every embedded system has

it's own timers and counters, but they are usually related to a unspecific starting time. In addition,

the Flyport Real Time Clock Calendar (RTCC) must be set to a starting point, and this setting should be

done by a user task.

With SNTP, Flyport can synchronize the RTCC with real time, or send emails at defined actual times,

with “timestamps,” or display a webpage with a constantly updated clock value.

NOTE: SNTPClient service is not enabled by default project configuration. Please use IDE wizard to

enable it, or compilatiling process will fail.

SNTP Functionalities

The result of a SNTP request will be a 32 bit (DWORD) that is the count of seconds from January 1

1970 to the current time. So 0 is the value related tot January 1

, 1970 00h:00min:00sec, 3 is the

value at 1st January 1970 00h:00min:03sec, and so on.

Converting functions are used to extract the actual time from the 32-bit value obtained from an SNTP

request. To convert the DWORD value to a user friendly structure in the openPicus framework, 3

processing steps are needed:

DWORD → Tme_t → struct tm

Using this 3 step conversion, all the timing values become easy to access and are formatted as

minutes, seconds, days, months, etc...

An external file called “heap.s” is needed to perform the conversion. The contents of heap.s is:

.section my_heap,heap

.space 0x0080

The heap.s function contains just a few commands, but they are necessary for correct compilation of

the SNTP helper functions.

This file should be included or created in a project using the “External Libs” tool.

NOTE: If the “external lib” tool is used, the “heap.s” file should be placed outside the project folder!