how to use RTC to store a local time in TM4C ?

Hae Ryong Jung

Other Parts Discussed in Thread: EK-TM4C129EXL, EK-TM4C1294XL, SW-EK-TM4C129EXL

Hi All,

I'd like to develop reporting event device with TM4C129, this device need to report event type and time, and connected to server via Ethernet.

so Server could set initial local time to device and device report back event with time info.

I think I need to use RTC as local clock to get current time, then how can I do it ?

please let me know any reference or example

Thanks in advance

Best Regards,

Hae Ryong

over 8 years ago

0 f. m. over 8 years ago

Guru 11940 points

Either an implementation of NTP or a similar protocol (not sure if there is any for the TM4C...).

Or, something like DCF77, as exists in Western Europe. It would require some additional hardware, but be supposedly of less effort in regard to the implementation (compared to a network time protocol). Pretty sure there is something similar in your region.

0 Amit Ashara over 8 years ago

TI__Guru**** 244400 points

Hello Hae

NTP is already implemented as part of the TI RTOS framework (see the EK-TM4C129EXL qs_secure_iot example)

0 juanquique_22 over 8 years ago in reply to Amit Ashara

Expert 1535 points

Hi Amit

I can't find the example you say, I just find qs_iot in ek-tm4c1294xl examples and I didn't see any NTP or TI RTOS use.

0 Amit Ashara over 8 years ago in reply to juanquique_22

TI__Guru**** 244400 points

Hello Juan,

Please go through the following landing page

www.ti.com/.../sw-ek-tm4c129exl

You would need to perhaps use a EK-TM4C129EXL for this task.

0 Hae Ryong Jung over 8 years ago in reply to Amit Ashara

Expert 2150 points

Hi Amit,

I have downloaded sw-ek-tm4c129exl, and I could not found qs_iot example in it.

however I have found qs_iot example in ek-tm4c1294xl.

but I cannot see any NTP related codes in it. maybe I missed it, would you please check again ?

BTW, I don't think I should use NTP in my device, since device can request server to provide current time info.

what I am concern is how to use internal RTC to store time info(maybe epoch representation)

thanks for your further response.

Best Regards,

Hae Ryong

0 Amit Ashara over 8 years ago in reply to Hae Ryong Jung

TI__Guru**** 244400 points

Hello Hae Ryong

My apologies. I should have asked you to download SW-SECURE-IOT-DEMO software package.

However, since you can get the time from the server, you would need to check the periodic request and update the RTC counter. Once updated you could rely on the local time from the RTC counter.

0 Hae Ryong Jung over 8 years ago in reply to Amit Ashara

Expert 2150 points

Hi Amit,

Thanks a lot,

I can find NTP reference code at secure_iot_demo example.

I think I had better use NTP to get current time directly.

then set this value with Second_set() in RTOS, and then get time value using Second_get() at any time.

I don't need to use RTC.

Best Regards,

Hae Ryong

0 Amit Ashara over 8 years ago in reply to Hae Ryong Jung

TI__Guru**** 244400 points

Hello Hae,

Absolutely. Relying on the NTP is a better method if the device is always connected. But having a back up in RTC can allow for logging downtime, etc.

Arm-based microcontrollers

Arm-based microcontrollers forum

how to use RTC to store a local time in TM4C ?