Alternatives to the nRF24L01+ ?

The nRF24 is simple to work with and very versatile.

However Nordic recommends that the nRF24L01+ should not be used in new designs so, presumably, they have plans to discontinue production at some time in the future. However the nRF52xx devices that they recommend for new designs are conceptually completely different as they include micro-processors. The few breakout boards that are available for the nRF52xx devices are physically a great deal bigger than the common nRF24 modules which makes them unsuitable for small projects. As well as which they are a lot more expensive.

It is possible to make a very small wireless package with an ESP8266-07 using ESP-NOW but it uses a great deal more energy than the combination of an nRF24 and an Attiny - presumably because its clock-speed is about 10 times higher. For radio control applications sleeping to save power is not really an option when the model is in motion.

I'm not worried that supplies of the nRF24 are going to dry up next week, but if anyone has suggestions for alternatives I will be interested to consider them.

...R

2.4Ghz is indeed a band that is more user friendly that the bands used by typical UHF modules, its pretty much a worldwide allocation with few to no duty cycle restrictions and heaps of bandwidth.

The obvious choice for an alternative 2.4Ghz device would be the SX1280 LoRa modules. Capable of 203kbps air rate in LoRa mode, 1.3Mbps in FLRC mode.

The LoRa modes will go a fair bit further than most (all?) other 2.4Ghz radio modules and are capable of stupid long range at slow data rates. I have used an SX1280 as a balloon tracker, it worked out to 89km, as did the distance measuring capability, the SX1280 has the ability to measure distance from time of flight of a packet exchange.

Sleep mode power use 1uA.

Also has BLE PHY layer compatibility apparently, but not played with that.

And someone has written an Arduino library that allows for most applications written for an SX1280 to be easily ported across to the SX127X and SX126X UHF LoRa modules, handy if you need even more range .......

Thanks. I have not been able to find a website with SX1280 modules so I can get an idea of their size and price. The lower frequency SX127x modules seem to need large antennas which would make the whole package a lot less convenient than the nRF24.

...R

The Ebyte E28 modules seem to go for around $6 on AliExpress.
They are around the same size as an ESP-12 module (24×15 mm), and have a PCB antenna as well as a U.FL connector. Even if the PCB antenna isn't good enough, you could still use a flat 2.4GHz antenna like the one used in laptops, for example.

Also see this video from Andreas Spiess: #323 Connected Light Sensor with 2 4GHz LoRa: How is its range? (SX1280, Arduino, ESP32) - YouTube

Pieter

Plenty of SX1280 to be found on Aliexpress.

There are versions with PCB antennas and u.fl option and modules similar to the RFM98 style UHF LoRa modules for external antenna.

Versions with 500mW, which would give rediculous LOS long range capability, 500km+ ?, where legal.

One thing that is a dissadvantage with SX1280 is that there does no appear to be modules directly sold with 0.1" pinouts, although there are breakout boards available.

The RFM98 style modules from NiceRF have 2mm spacing mount holes. Same as those ESP8266 breakouts, so I guess you could use one of those too.

PieterP:
The Ebyte E28 modules seem to go for around $6 on AliExpress.

Thanks for the link. That does seem to be a promising solution. I must see if I can find a UK supplier. I don't have the patience to wait for supplies from China.

...R