How much range did you get with 2 nrf24 cheapest module communicate?

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WindyYam
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How much range did you get with 2 nrf24 cheapest module communicate?

Post by WindyYam » Fri Feb 02, 2018 2:45 am

What I mean are those common nrf24 from china vendor with PCB antenna. I know most of them are fake, but more or less they are compatible clones with same specs.

I'm doing with 2 of them but only get about 1 or 2 meters without losing packet. I'm using lib https://github.com/nRF24/RF24

According to the following picture these PCB antenna have a higher sensitivity on some direction but even if i place them in the right direction still i got no more than 4 meters. By setting the tx power to MAX it's just 50% range increased. and still in some direction got heavy packet loss. I'm doing a wireless motion sensor so it's quite anonying
095829zniedw8nns1s881t.jpg
095829zniedw8nns1s881t.jpg (49.06 KiB) Viewed 254 times
Are there any special care should be taken into consideration ? The power is directly supplied by BP ldo output but I added decouple cap of 10uF
Last edited by WindyYam on Fri Feb 02, 2018 3:42 am, edited 1 time in total.


WindyYam
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Re: How much range did you get with 2 nrf24 cheapest module communicate?

Post by WindyYam » Fri Feb 02, 2018 3:44 am

so the solution is switching to 250kbps and minimize packet length? well 250kbps is sort of affordable but I cant minimize my packet below 17 bytes. anyway, not all the nrf24s were capable for 250kbps I'm afraid, it depends on the subtype

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Manny
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Re: How much range did you get with 2 nrf24 cheapest module communicate?

Post by Manny » Fri Feb 02, 2018 3:01 pm

Used the very cheap ones a few times, never had any problem with them reliability wise, never had to resort to putting extra capacitors. Realistic range line of sight is about 30 meters in open air, or a couple of walls indoors if you're lucky. The ones which claim to be amplified with separate antenna don't fair much better in my experience.

WindyYam
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Re: How much range did you get with 2 nrf24 cheapest module communicate?

Post by WindyYam » Fri Feb 02, 2018 4:18 pm

Manny wrote:
Fri Feb 02, 2018 3:01 pm
Realistic range line of sight is about 30 meters in open air, or a couple of walls indoors if you're lucky
did you config something, like the tx power, packet length, datarate and else, or just put it to work with default settings? If that's the case, ok maybe I should do a comparison on those modules on taobao :(

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Manny
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Re: How much range did you get with 2 nrf24 cheapest module communicate?

Post by Manny » Fri Feb 02, 2018 6:36 pm

Data was set at 250Kbps, power max which is default in the lib I used. Only thing I can suggest is choose a different channel, you might be getting interference from WIFI etc looking at my old sketch I used channels above 60.

WindyYam
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Re: How much range did you get with 2 nrf24 cheapest module communicate?

Post by WindyYam » Sat Feb 03, 2018 7:31 am

i ve test some interesting result that, i have a bunch of "nrf24" modules, if i set them to channel 0, got some decent performance. but if i raise the channel up to 50 100 120, the packet loss rate gradually increases till completely mismatched, they seems do.not like each other as the channel grows. result was done by place 2 modules as close as possible so Its not by environment interference

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Manny
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Re: How much range did you get with 2 nrf24 cheapest module communicate?

Post by Manny » Sat Feb 03, 2018 11:02 am

WindyYam wrote:
Sat Feb 03, 2018 7:31 am
i ve test some interesting result that, i have a bunch of "nrf24" modules, if i set them to channel 0, got some decent performance. but if i raise the channel up to 50 100 120, the packet loss rate gradually increases till completely mismatched, they seems do.not like each other as the channel grows. result was done by place 2 modules as close as possible so Its not by environment interference
Interesting but I'm not sure having them so close together is a good idea test wise. Have you tried any other library like RF24_STM?
The setup I used, was a nRF24L01P+PA+LNA as the base node and cheap pcb antenna modules as childs. If you're looking for range maybe RF 315/433MHZ is the way to go..I have no experience with these.

WindyYam
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Re: How much range did you get with 2 nrf24 cheapest module communicate?

Post by WindyYam » Tue Feb 06, 2018 6:24 am

After alot of experiments I think I start to learn the pattern.
In my setup I have a "nrf24 + pa + lna + rubber Antenna" module as the local part, the remote part is a pcb antenna rf24. Both are directly connected to boards' ldo 3.3 output. In my code I writed the local part tx power to RF24_PA_MAX, this cause the setChannel part unmatched between both module(still dont know why). After set tx PA to RF24_PA_LOW now the setChannel works up to channel 125 with the same packet loss rate as channel 0, and by setting channel 120 the range is extended too though still not too much,By far I'm already pleased with that performance.

To extends further I think I should got some genuine modules, not the fake one

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RogerClark
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Re: How much range did you get with 2 nrf24 cheapest module communicate?

Post by RogerClark » Tue Feb 06, 2018 7:52 pm

I experimented with some nRf24 boards when they first come out a few years ago, but I was disappointed with the range.

I think it was Ok if both devices where in the same room, but it was useless for me to communicate between different rooms in the house , and impossible to communicate between the garage and the opposite side of the house.

I ended up using a 433Mhz data module instead, as they have much longer range, and I do not need high continuous data rate, as I only send power logging data of 32 bytes , once per second.

I used a nRF905, but there are other FM data modules e.g. from Hope RF.

I also use nRF51822 Bluetooth Low Energy modules, however the range is not very good with these either.
BLE is on 2.4 GHz like the nRf24, so probably has similar characteristics, in fact I think the nRF5x series can communicate with nRF24 via special low level libs which override its BLE operation.

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