nRF24 transmission range

RE: nRF24 transmission range

Alessio — Tue, 12 May 2020 13:11:34 GMT

Sorry???
You not able to solve my problem and so you think is enought to close the ticket by suggest to me to ask a replacement???

RE: nRF24 transmission range

ketiljo — Tue, 12 May 2020 11:58:02 GMT

If you suspect that the kit is faulty, please ask for a replacement from the distributor where you got it from.

RE: nRF24 transmission range

Alessio — Mon, 11 May 2020 15:14:47 GMT

Setup:
Upper traces: Yellow and Cyan
Under traces: Magenta and Blue
Transmitter: device in the left angle (lower) in the video
Receiver: device in the right angle (upper) the device is directly connected do the PC (only for power supply)

Oscilloscope Traces
Upper traces are the data sent from Transmitter device
Lower traces are the receiving data by Receiver device

CASE ONE - Video MOV_1155
Transmitter receiving data from USB and transmit them, when I put the hand between the devices the communication stop workingdevzone.nordicsemi.com/.../MOV_5F00_1154_5F00_000.rar devzone.nordicsemi.com/.../MOV_5F00_1155.rar

CASE TWO – Video MOV_1154_000
When we move in air the transmitter the data are lost by the receiver (the transmitter continue to send the data correctly)

CONCLUSION
We can confirm that the problem is in your KIT devices, I ask you to send us a complete Transmitter and Receiver KIT (nRF24 or nRF5X)

RE: nRF24 transmission range

ketiljo — Fri, 08 May 2020 09:00:30 GMT

The setup looks ok. To rule out the USB traffic, setup the receiver to toggle a pin and check the status if it, with a LED or an oscilloscope to check that you are receiving the packets you should.

One problem with these older devices is that debugging isn't easy, but you can toggle pins to check where the packets get lost.

If you don't have noise on the channel and the radio is setup correctly, which it looks like it is, you should not see packet loss like this.

RE: nRF24 transmission range

Alessio — Thu, 07 May 2020 10:40:29 GMT

Any news regarding the setup?

RE: nRF24 transmission range

Alessio — Wed, 06 May 2020 17:12:41 GMT

Here are some photos on how devices are used. There are less than 2m from TX and RX and the transmission is fine only if no one is moving in between. If someone is sitting on the chair we can observe delays of some seconds and the data flowing is non linear.
If one of the PC is 6m away from the other (in the same room) the transmission never begin.

The TX is the one with the USB cable.

RE: nRF24 transmission range

ketiljo — Wed, 06 May 2020 14:30:53 GMT

I've taken a look at the code and there's no obvious errors that I can see.

Can you post a picture of your setup please? There's something seriously wrong with your setup that causes this.

RE: nRF24 transmission range

Alessio — Wed, 06 May 2020 08:16:11 GMT

We had post both firmwares used in TX and RX devices some weeks ago. The TX side was the Nordic nRF2726 PCB and the RX side was the Nordic USB dongle both from development Kit nRF24LU1P-FxxQ32-DK as said above. Both devices exchange data over USB.
We leaved the unbranded modules.

Are you able to give us a solution based on material we'd sent in within few days? Otherwise we need to change supplier and ask to NS or your reseller to refound our money...

RE: nRF24 transmission range

ketiljo — Wed, 06 May 2020 07:16:16 GMT

Can you post a picture of your setup please? If you're using stock, unchanged modules and have not changed any of the register values, there's no reason for this short range.

The unbranded modules, unless you have bought them from a distributor of Nordic devices, most probably have fake chips and can't be trusted.

RE: nRF24 transmission range

ketiljo — Thu, 30 Apr 2020 13:54:21 GMT

Ok, so you can rule out USB3.0 noise then. It's puzzling why you see this short range. You should have no problems getting a range of 30+ m at 2 Mbps and more at 1 Mbps.

The radio in all nRF51 series are the same as the nRF24L01+, but the nRF52 series radio is very different. The shockburst HW part is now done entirely in SW to make it more flexible. The sensitivity is somewhat better as well so range will be higher. But since you're only seeing a range is a few meters, there's something wrong, probably in SW. Try using all default register values and see it that does it better.

RE: nRF24 transmission range

Alessio — Mon, 27 Apr 2020 13:33:37 GMT

Hi,

for the USB port I used many of them, directy into USB3 on PC, with USB2 1,5m extension cord, in an USB2 hub but with a not appreciable difference. With the extension cord it seems to be a little more stable.
For the addresses I'm using E7,01,01,01,01 for pipe0 and E7,01,01,01,02 for pipe1.
The ouput power is 0dBm (as default).
Are new devices of nRF52 series based on the exact same system or they were tuned to be more stable? (uising the same technology live ESB or Gazell).

Thanks

RE: nRF24 transmission range

ketiljo — Mon, 27 Apr 2020 13:09:28 GMT

You will always have packet losses with a radio link. So your protocol must take this into account. ESB is a simple protocol that can re-transmit the packet a number of times. But even this may not be able to get all the packets through. So you might have to have an additional layer on top to handle that. But at this short range, you shouldn't loose more than one occasional packet.

When you use the nRF24LU1+ as the receiver, it this plugged into a USB3.0 port? If so, the noise from the USB traffic may affect the reception. Try using an extension cable.

What address are you using here, the default address? This should be fine. The only address that does not work is 0x55,55.. and 0xAA,AA.. as this is a continuation of the preamble and will cause false address match in the receiver.

The CRC is calculated for the whole packet, including the address. If the CRC fails, the packet will be discarded.

You have set the output power to 0 dBm?

The PCB antennas on the modules should be good enough.

RE: nRF24 transmission range

Alessio — Fri, 24 Apr 2020 13:45:33 GMT

Hi,

Any news on the phenomenon?

I'm still doing some tests. Here is the setup. The transmitter is sending 3 byte every 10ms (each byte is an increment from the same counter i.e. 0 1 2, 3 4 5, 6 7 8, etc). On the receiver side sometimes there are record like 3 7 8.

Is it guaranteed that the checksum system on the ESB with AA receives only correct data? And so the problem is in my firmware of nRF24LU1+ which is moving data from radio to USB and not proper managed for interrupts from radio and USB?

Thanks.

RE: nRF24 transmission range

Alessio — Tue, 21 Apr 2020 07:53:38 GMT

Hi, so far I tried 3 different channels, 0, 54 and 70. But the problem is still there.

We have the development kit nRF6804 rev.1.2 2019.12 and 3 unbranded modules equipped with nRF24L01+.

To avoid any issue with the 3 modules, I used the nRF2726 as a transmitter and the nRF24LU1+ USB dongle as a receiver both from your development kit.

The transmission is fine within 1.5m away. Between 1.5-2m only if devices are in a fixed position. If someone is moving between them or one device is moved (a gently movement like rotating the pcb) the transmission slows down and/or lose packets. Trying the system with TX and RX at 8m of distance the reception never begins using nRFgo development kit PCBs. But with 2 of the 3 unbranded nRF24L01+ modules as transmitter and the USB dongle from the development kit as receiver, the reception works more or less fine even at 8m distance.

The firmwares on the devices were developed from your SDK material using the enhanced shockburst examples of PTX and PRX integrated with the bootloader example to manage the USB part. I attach keil projects and .hex files.

Where I'm testing there is a WiFi network.

What can I do? Try other channels? Select a 1Mbps bitrate instead of 2Mbps?

Using the nRF2727 module with a physical antenna instead of a PCB antenna can bring some benefits? We didn't try it yet because we don't have a physical antenna compatible with the connector.

Thanks.

devzone.nordicsemi.com/.../TX_5F00_nRF24LU1P.zip devzone.nordicsemi.com/.../RX_5F00_nRF24LU1P.zip

RE: nRF24 transmission range

ketiljo — Thu, 16 Apr 2020 12:22:05 GMT

1.5 m is extremely short, you should get 40+ meters easily. Try another frequency in case there's something that disturbs the channel. Same channel on both sides of course. Use the default address