NRF52840 won't receive from some TI CC2538 chips

RE: NRF52840 won't receive from some TI CC2538 chips

zrivard — Fri, 13 Mar 2026 19:46:22 GMT

Hi Libertas,

On the off chance that you're still troubled by this issue, I've just experienced the same phenomenon with a few of TI's CC2420 and various nRF chips.

The cause of my issues were that some of the CC2420's were struggling to ramp up their internal PAs in time for the preamble transmission, leading the nRF chips to fail to synchronize properly with the transmitter, generating CRC errors.

If you still require a solution to this problem, I can share some of the details as to how we tested and verified what the root of the problem was.

Cheers,

zrivard

RE: NRF52840 won't receive from some TI CC2538 chips

Susheel Nuguru — Fri, 11 Nov 2022 07:56:25 GMT

[quote user="Libertas"]The nRF52840 802.15.4 sniffer firmware, which is 4 years old, won't receive 802.15.4 packets from some devices. Is there any updated version of the firmware?[/quote]

Not that I know of. I have But I have asked the internal team to see if there are any unpublished updates on this but I have not received any answer yet. Most likely there are no updates to the sniffer tool you are using. There does not seems to be any active development ongoing on this sniffer tool.

RE: NRF52840 won't receive from some TI CC2538 chips

Libertas — Thu, 10 Nov 2022 02:18:25 GMT

I have invested a lot of effort in the nRF solutions. And I am baffled by the symptoms I experienced.

Let me rephrase the question a little bit.

The nRF52840 802.15.4 sniffer firmware, which is 4 years old, won't receive 802.15.4 packets from some devices. Is there any updated version of the firmware?

I do hope it is due to something I did wrong on my side as I am still feeling surreal about it.

RE: NRF52840 won't receive from some TI CC2538 chips

Susheel Nuguru — Wed, 09 Nov 2022 18:03:44 GMT

I see, thanks for making the crystal clear. If you are developing another mesh protocol which is not one of our solutions, then I do not think I can help you much here. Our hardware is proven to be 802.15.4 capable and we have protocols that work on it. It is not possible for us to validate the timing and other implementation details of protocols that are not our solution.

RE: NRF52840 won't receive from some TI CC2538 chips

Libertas — Wed, 09 Nov 2022 14:04:26 GMT

I am not developing Thread. I am developing another mesh protocol that we are going to open source.

That's why I am testing plain 802.15.4 reception with Nordic sniffer firmware. And it couldn't receive from 2 out of 9 devices.

RE: NRF52840 won't receive from some TI CC2538 chips

Susheel Nuguru — Wed, 09 Nov 2022 11:13:25 GMT

[quote user="Libertas"]First of all, Thread is based on 802.15.4, and I am discussing 802.15.4 reception on nRF52840.[/quote]

I understand that, but there are two Thread solutions from us,

1. Thread solution based on old nRF5SDK which I am guessing is the one you are using.
2. 'Thread solution based on our latest nRF Connect SDK.

The one you are using seems to be on the older SDK which are in frozen now and no new development happens on that SDK. We recommend you to use the latest version of NCS.

RE: NRF52840 won't receive from some TI CC2538 chips

Libertas — Tue, 08 Nov 2022 14:23:20 GMT

First of all, Thread is based on 802.15.4, and I am discussing 802.15.4 reception on nRF52840.

Secondly, I didn't have reception problems with ALL my devices based on TI CC2538. Out of 9 devices, there are only two devices that have the problem.

Thirdly, I am using the official Nordic sniffer firmware (for 802.15.4) which I downloaded from your GitHub page:

https://github.com/NordicSemiconductor/nRF-Sniffer-for-802.15.4

It is obvious that if it cannot receive, it cannot communicate.

I am planning to test more devices on my side. In the meantime, if you have an updated version of the sniffer firmware I would like to try and test again.

RE: NRF52840 won't receive from some TI CC2538 chips

Susheel Nuguru — Tue, 08 Nov 2022 13:27:03 GMT

We go through the interoperability tests during the Thread certification, so it should have been ok when communicating with other Vendor thread devices if they have done the same. Also we recommend you to use the nRF Connect SDK instead of the nRF5SDK. nRF5 based SDK are old and are in maintenance mode only. All new features and fixes will be coming the nRF Connect SDK only.

RE: NRF52840 won't receive from some TI CC2538 chips

Susheel Nuguru — Tue, 01 Nov 2022 08:20:17 GMT

It does not look like we have any data on the interoperability against this specific chip with the setup you have. I do not get any additional insights from internal queries, so I have to assume that we have not tested this.

RE: NRF52840 won't receive from some TI CC2538 chips

Libertas — Mon, 31 Oct 2022 12:51:25 GMT

I just wanted to clarify again. In the above setup, the nRF52840 dongle did not participate the communication.

It just listens as a sniffer, with the Nordic official sniffer firmware.

As a sniffer, it is supposed to be able to receive all packets in that channel. But when two nearby devices are talking, it can only see packets from one device, and another device is completely invisible to the sniffer dongle.

RE: NRF52840 won't receive from some TI CC2538 chips

Susheel Nuguru — Mon, 31 Oct 2022 12:06:23 GMT

I will have to show this to someone who have a bit deeper knowledge in the per packet transaction and ACK/NACKing of these packets. Will be back with more info when I get some.

RE: NRF52840 won't receive from some TI CC2538 chips

Libertas — Thu, 27 Oct 2022 13:31:38 GMT

OK. Here is the Wireshark capture with the nRF52840 dongle as sniffer.

There should be 4 APS transactions in this period. Each transaction is between the Hub (short address 0x0000) and a device with a short address of 0x0006 and a long address of 00:12:4b:00:19:3c:9b:9e.

Both devices are on TI CC2538.

As you can see, somehow, the nRF52840 dongle can only see packets from Hub. It completely lost the traffic from another device.

On the other hand, the transactions were going smoothly with direct communication and no MAC retry.

Each transaction shall generate 4 packets:

1. APS request from 0x0000 to 00:12:4b:00:19:3c:9b:9e (0x0006)
2. MAC acknowledgment of request from 0x0006
3. ASP response from 0x0006 to 0x0000
4. MAC acknowledgment of response from 0x0000

Because the nrf52840 dongle can only see traffic from 0x0000, it can only record two packets per transaction.

As you can see from the capture below. Each time the sequence number of ACK didn't match the original. That's because both packets are from Hub (0x0000). The dongle lost two packets from the other device in the middle of the transaction.

These are plain 802.15.4 packets. The two devices are about 9 feet away but the "hidden device" is inches from the dongle and the dongle still can't see anything from it.

I am banging my head right now!

RE: NRF52840 won't receive from some TI CC2538 chips

Susheel Nuguru — Wed, 26 Oct 2022 10:14:59 GMT

I cannot find any references of such issues internally, so I will try get some assistance from my colleagues to see if they know about this. Meanwhile maybe a sniffer trace for the thread would help to understanding the timings of the packets transmitting from TI CC2538

RE: NRF52840 won't receive from some TI CC2538 chips

Libertas — Mon, 24 Oct 2022 13:08:25 GMT

Hi Susheel,

Thank you for your quick response. Please see my answers below:

1. The whole setup is 802.15.4. There is no BLE involved.

2. My own firmware is based on nRF5 SDK 17.1.0. My own firmware and the official Nordic sniffer firmware can only see 6 out of 8 devices on TI CC2538.

3. All TI devices can see the nRF52840 dongle. A TI2530 dongle-based sniffer can see all devices including the nRF52840 dongle.

4. All TI devices are on XTAL.

So the symptom appears to be that the nRF52840 dongle won't receive plain 802.15.4 packets from some of my TI devices.

I still can't believe what I have experienced but it just happened.

RE: NRF52840 won't receive from some TI CC2538 chips

Susheel Nuguru — Mon, 24 Oct 2022 07:01:00 GMT

Hi Libertas,

I have not seen or known any BLE interoperability issue between CC2538 and nRF52840. That does not mean that there is none, it just means that you might be the first to come across this. Before we can proceed on this I would need some information on your environment.

Which softdevice version and SDK version are you using on nRF52840 dongle? (not the sniffer, but your own firmware version based on which SDK and softdevice version?)
Does the nRF52840 run on XTAL LFCLK or internal RC?
Does your 8 devices of TI CC2538 run on XTAL LFCLK or RC?
When you say not able to receive packets, do you mean advertising packets or connection packets?
If advertising packets, what is the interval of adv and scan and If connection packets, what are the connection parameters?

When you are testing two devices that are running on the same clock accuracy, and jitter the same amount then it more probable that the devices find each other. If you are using RC oscillator or some other clock on TI CC2538 with lower clock accuracy, it is no mystery that they find each others packet as eventually as they all of them are running on the same clock accuracy.

If nRF52840 dongle is running the firmware on XTAL LFCLK with little bit more accuracy that the peer, then it is probably more strict with the timing of packets.