WirelessHART over TIMAC on cc2538

Kiran G

Other Parts Discussed in Thread: TIMAC, CC2538, CC2520, MSP430F5636

Hi,

In this post Peder says that it is possible to use TIMAC as the MAC layer for WirelessHART. Is this possible? Does TIMAC API support the WirelessHART requirements like TDMA, channel hopping etc?

Kiran

over 11 years ago

0 TheDarkSide over 11 years ago

TI__Genius 16570 points

Hi,

while the CC2538 is a device capable of supporting WHART stack, TI-MAC API don't support channel hopping or TDMA WHART framing.

Thanks,

TheDarkSide

0 Firefighter over 11 years ago in reply to TheDarkSide

TI__Genius 12480 points

You would need to use the IEEE802.15.4 Hardware API in order to implement WHART on CC2538.

0 Kiran G over 11 years ago in reply to Firefighter

Prodigy 120 points

Can you please clarify what you mean by IEEE802.15.4 Hardware API? You mean using the CC2538 programming guide and implementing the MAC layer ourselves?

0 Firefighter over 11 years ago in reply to Kiran G

TI__Genius 12480 points

yes.

0 Kiran G over 11 years ago in reply to Firefighter

Prodigy 120 points

Would it be possible to use TIMAC as a relay. My code will prepare the WHART MAC frame and send it via TIMAC API. TIMAC should not add any MAC header/footer. It should just pass it on to the PHY layer. This way I dont need to worry about PHY layer programming.

From the API document I could see that "MAC_McpsDataReq" is the only API function which allows data transfer to TIMAC layer. And we need to preallocate the buffer for the full MAC frame before sending the data. I am assuming the TIMAC will overwrite this buffer with the header info. Is it possible to skip this so that I can fill the MAC header etc from my code.

0 TheDarkSide over 11 years ago in reply to Kiran G

TI__Genius 16570 points

I think it is better for you to start from this code, rather than from TI-MAC
www.ti.com/.../swrc272
TheDarkSide

0 Kiran G over 11 years ago in reply to TheDarkSide

Prodigy 120 points

Does the RF API provided in the per_test code completely abstract the RF operations( configuration, tx,rx) etc. Or do I need to implement functions to support PHY layer using the Hardware API?

0 TheDarkSide over 11 years ago in reply to Kiran G

TI__Genius 16570 points

No, they abstract the PHY so you can build whatever packet you want on top of a standard 802.15.4 frame, DSSS OQPSK modulation @ 2.4 Ghz.
TI-MAC API instead doesn't allow you to modify the MAC header.

0 LeonardEllis over 10 years ago in reply to TheDarkSide

TI__Guru 71526 points

I'm a bit confused here - my understanding is that HART is a current-loop protocol, so how is it implemented wirelessly?

Having said that, and seeing the HART governing body has approved WHART, do we have a way to implement this with the CC2538, or perhaps CC26xx?

~Leonard

0 Morten Braathen over 10 years ago in reply to LeonardEllis

TI__Mastermind 19575 points

Hi Leonard,

I believe we have a solution with the MSP430F5636 and CC2520 from a 3rd party. Not sure about a CC26xx solution yet.

WHART uses the IEEE 802.15.4 -2006, (so it is a IEEE compliant PHY PDU with maximum payload of 127 bytes.
It is a secure and TDMA based wireless mesh networking protocol

It specifies three principle elements

- WHART Field Devices (WFD)
- WHART Gateways
- WHART Network Manager

0 LeonardEllis over 10 years ago in reply to Morten Braathen

TI__Guru 71526 points

I'm also going to suggest they look at using 6LoWPAN, as we already have a solution here. Will convey the WHART info as well - thanks!

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WirelessHART over TIMAC on cc2538