NRF24L01+PA+LNA power consumption

[Mark Swift]

I saw this on Hackaday, could we make this change in MySensors?

"Don’t use polling over SPI to check if there is a received packet like most of the libs out there do. This increases the noise. Use the IRQ pin"

@hek

[hek]

In the development branch we do use irq nowadays, if you define

#define MY_RF24_IRQ_PIN xx

It also de-queues messages from the NRF24 quickly, which reduces missed messages.

[Mark Swift]

@hek amazing, I never knew that.

So all I would do is define this line in my sketch and connect up the IRQ line?

I presume I can use this on both my gateway (ESP8266) and my nodes (Nano / Uno)?

[hek]

The ESP still doesn't support this feature due to lack of SPI transaction support (if I remember correctly? @Yveaux ).

[Yveaux]

@hek @Mark-Swift More precisely, it misses the interrupt protection for SPI transfers. Ref https://github.com/esp8266/Arduino/issues/1943.

But the queueing is not yet in development, as far as I know -- it is in my personan testing branch https://github.com/Yveaux/Arduino/tree/development_rxqueue

[Oitzu]

@Mark-Swift there are basicly effects that could occur while you holding the module:
1.) You are forming a very small capacitor between you and the module.
Much unlikely to be the reason.
2.) You are functioning as an antenna for the module.
Also much unlikely, you would probably bring more noise then signal in the system.
3.) You function as a shield to the module.
More likely. I got the same behavior with insufficient shielding.
The shielding works ungrounded in low noise environment but needs to be grounded in a high noise environment.
This happens, as example, if a insufficient shielded switching power supply is nearby.

Please make absolutely sure that your shield is properly grounded!

[Mark Swift]

@Oitzu The shielded modules appear to have the shield well grounded?

[Oitzu]

@Mark-Swift does "appear" mean you actually measured it all the way to ground or that you believe that it should be well grounded?

[GertSanders]

@hek
So it would make sense to connect the IRQ pin of the radio to the processor ? Any pin ? Or is it meant for INT0/INT1 pins only ?

[karl261]

@GertSanders Did you find an answer to this? With 2.0.0 would it be better to use IRQ now? Just connecting the pin and adding the IRQ line?

[Yveaux]

@karl261 It isn't used by default in 2.0.0, but can be used in the 2.0.1 development brach. I would advise you to connect the nRF irq pin to into (pin 2), to be prepared for later usage.

[karl261]

@Yveaux So, basically this means that in the future we can have the arduino sleeping and when a message comes in it wakes up from the interrupt? Sounds like repeaters could run on battery then. If there is not too much traffic.

[hek]

No, running repeaters on battery is probably not possible. Keeping radio in listening-mode takes too much juice.

[karl261]

@hek Ah yes, that's right. The radio needs to be on. I forgot about that. We need an over the air interrupt... ;-)