Configure Coded PHY

RE: Configure Coded PHY

Vidar Berg — Fri, 19 Jan 2024 15:29:21 GMT

Hi,

If you have not yet manufactured the new boards, you may create a new private support ticket to have the layout reviewed by one of my colleagues.

Best regards,

Vidar

RE: Configure Coded PHY

domko99 — Fri, 19 Jan 2024 12:32:50 GMT

Hi,

no, unfortunately no. We have developed new board which is not using module ACN52840 but only chip nRF52840 with external ceramic antenna (https://www.mouser.sk/ProductDetail/Quectel/YC0010AA?qs=HBWAp0VN4Rh%252BBydEKHtdNg%3D%3D). We will try the range on this board. We also considered to try Coded PHY with nRF5 SDK, maybe there will be different results, now we are developing with nRF Connect SDK. The last option is to buy two nRF52840 DK and try the range. We will see, thanks.

RE: Configure Coded PHY

Vidar Berg — Thu, 18 Jan 2024 11:49:34 GMT

Hi,

Apologies for the delayed response, this case has slipped through the cracks. Have you been able to resolve the issue in the meantime?

Best regards,

Vidar

RE: Configure Coded PHY

domko99 — Fri, 29 Sep 2023 09:33:39 GMT

Hi. I am sending you logs which you requested. Logs dont stop dead after 3 seconds, there are more logs.

Here are peripheral logs:

/cfs-file/__key/communityserver-discussions-components-files/4/peripheral_5F00_logs.txt

And here are central logs:

/cfs-file/__key/communityserver-discussions-components-files/4/central_5F00_logs.txt

Disconnected reason is 0x08 (the supervision timeout is hit (no packets from the peer is received in x seconds)). Thanks for any help, I will open new thread if you dont mind, where I will be asking just for dongles (devzone.nordicsemi.com/.../short-range-with-coded-phy). This is pretty old thread and maybe someone new from community will come and try to help. Nevertheless, thanks for your support.

RE: Configure Coded PHY

haakonsh — Fri, 08 Sep 2023 14:53:59 GMT

Sry for the late reply.

Your logs end after 3 notifications. I expect to see the output from the disconnected() callback:
printk("Disconnected (reason 0x%02x)\n", reason);

Does the logs really just stop dead after ~3 seconds, or are there more logs?

I'm looking for logs from boot until the connection disconnects.

Also you should set CONFIG_UART_CONSOLE=n when using USB CDC ACM as you can enter a bootloop if the logger subsystem is initialized earlier than the USB driver.

RE: Configure Coded PHY

domko99 — Mon, 28 Aug 2023 10:39:04 GMT

Hi, thanks for answer.

I have tried to set CONFIG_LOG_MODE_DEFERRED but it didnt help with distance.

I am sharing with you logs and files which you want to see below:

/cfs-file/__key/communityserver-discussions-components-files/4/6471.central.zip

/cfs-file/__key/communityserver-discussions-components-files/4/3326.peripheral.zip

RE: Configure Coded PHY

haakonsh — Thu, 24 Aug 2023 15:23:19 GMT

It could be an issue with logging, try to set CONFIG_LOG_MODE_DEFERRED.

Can you share any logs?

Can you share .config and zephyr.dts from build/sephyr/ ?

RE: Configure Coded PHY

domko99 — Tue, 15 Aug 2023 19:29:19 GMT

Hi, thanks for answer.
I determine the range by getting disconnected range.
For connection parameters, as I was using samples Peripheral HR Coded and Central HR coded, I used the connection parameters set in this samples. But I will provide you my codes which I was using.
devzone.nordicsemi.com/.../coded_5F00_phy_5F00_codes.rar
I will discuss the HW issue with my colleague. Thanks again for your answer, I really dont know what to try next, maybe it is USB port issue.

RE: Configure Coded PHY

haakonsh — Mon, 14 Aug 2023 18:56:50 GMT

This might be unrelated, but you need to enable CONFIG_LOG_MODE_DEFERRED.

How do you determine the range? is it the range at which you get a BT disconnect event?

What are your connection parameters? interval, slave latency, MTU size, DLE length and size, ect.

Can you share your project as a whole?

One potential HW issue could be a noisy USB3 port.

RE: Configure Coded PHY

domko99 — Wed, 19 Jul 2023 20:12:54 GMT

Hi, sorry for late reply. So we did cut off a piece of board as you suggested, but only the smaller portion of it, as we couldnt cut more because of wiring on board. I am sending you a photo.

But this cut off didnt help, I am getting the same results as before. The outside tested range with direct visibility is 63 m (according to Google Maps, set Coded PHY and 8 dBm power). The inside range is also low, same as before (approximately 8 meters, between boards only one block wall with a thickness of 30 cm). I have also tried to direct antenna acccording to radiation diagram of antenna (found here https://www.infineon.com/dgdl/Infineon-AN91445_Antenna_Design_and_RF_Layout_Guidelines-ApplicationNotes-v09_00-EN.pdf?fileId=8ac78c8c7cdc391c017d073e054f6227), it added some small distance, outside maybe 5 meters and inside almost nothing....

I dont think that bigger cut off which you suggest would make any major difference.... We have been also testing the transmit power of our board and dongle nrf52840 with spectrum analyzer and receiving antenna, and we have found out that they both have the same transmit power. We are really confused by it, as you have also mentioned that dongle does not have as good antenna as nrf module which we are using, but the results were the same (we have been testing without cut off). Also I have found some thread here (5 years old, https://devzone.nordicsemi.com/f/nordic-q-a/48978/no-measurable-range-increase-using-long-range-bluetooth-le-coded-phy), where they have been able to get 300 m distance from two dongles using Coded PHY, I have been testing it and I could not get nowhere near this number. I dont know if I have some strange conditions for my boards, or using bad code to set Coded PHY (I am using examples provided from Nordic) or something else... Would be possible for you to confirm that dongle is able to achieve 300 m distance with Coded PHY? Thanks for any help.

RE: Configure Coded PHY

haakonsh — Fri, 30 Jun 2023 22:37:15 GMT

The nRF52840 dongle does not have a good antenna due to it's tiny ground plane and is not suited for applications where range is critical.

I suggest you cut off the piece of board I've outlined below, use a hacksaw or dremel:

Can you share your layout files?

RE: Configure Coded PHY

domko99 — Mon, 26 Jun 2023 12:09:52 GMT

Hi and thanks for your answer. I didnt send you the other side of board, there is a cutout for antenna, see in image of my board below:

I also did some testing with two nRF52840dongle boards which I have. I have tried the same code above with Coded PHY, got same results (Connected: xx.xx.xx.xx.xx.xx (random), tx_phy 4, rx_phy 4) and the range was the same, at least in indoor environment. Is dongle capable of long ranges, are there any restrictions regarding the antenna of dongle board? Because the results look same, and this is original Nordic board.

I dont know what to test next, I dont have a nRF52840DK or other board from you. I am starting thinking to use external antenna, but I dont know if it will help.

Thanks for your answer.

RE: Configure Coded PHY

haakonsh — Fri, 23 Jun 2023 17:29:18 GMT

I believe "tx_phy 4, rx_phy 4" is in fact Coded PHY.

I think there's an issue with the design of your board, there should be a keep-out area on both sides of the module, at the right edge of the motherboard. The problem here is that the antenna of the module is 'de-tuned' by the presence of metal in its 'near-space'.

For reference you should should get ~1km range (outdoor, line-of-sight) with Coded PHY at +8dBm on a decent board. I suggest that you either get the module's Evaluation Kit from the manufacturer of the module, or get the nRF52840DK from us, as a reference.

Note:
Coded PHY trades 8x longer on-air time per symbol for a higher receiver sensitivity. Where a higher sensitivity means that the receiver can resolve signals that are of lower power than regular 1mbps PHY (longer range).

However, that 8x longer on-air time is also 8x more likely to encounter spurious interference from other radios, especially Wi-Fi routers. That means that if you are in a typically noisy environment like an office space, the likelyhood that any given BLE packet will be successfully transmitted can be lower for Coded than 1mbps PHY. In this scenario, Coded PHY will still have longer max range than 1mbps if a given Coded PHY transmission is not interferred with.

The opposite is true for 2mbps PHY, where a lower receiver sensitivity is traded for shorter on-air time per symbol. In extremely noisy environments 2mbps PHY can actually have significantly higher throughput than 1mbps or Coded PHY (at a range where the throughput of 1mbps and Coded PHY are closer to zero), but with much shorter max range.

-edit:

If you share your schematics and layout files we can take a look and see if there are any other issues.