I'm not sure if this is the correct forum to post this. I have a strange problem with nRF24L01 radios.
With the same 4 sketches on 4 different boards ( 2 nanos, 1 uno and 1 mega). the auto acknowledge works fine. using an Addicore brand
With these Maker Focus on Amazon it does not. They work fine if they're just receiving or transmitting data, but not if they have to perform an auto acknowledge. The manufacturer claims autoack works on them.
The Maker Focus radios have an external antenna and the Addicore's do not.
It does not matter which sketch is on any particular board. I've switched them around repeatedly. All the boards run all of the sketches perfectly if using the Addicore radios
I've attached the 4 sketches I'm using. Two of the boards are nanos with a built in RF-24, one is an Arduino Uno and the other is a Arduino Mega. All sketches work on all of the boards when I'm using the addicore radios or the nanos with the built in radio. I have tried two different Maker Focus radios on the Uno and the Mega.
Can anyone give clueless me a clue as to why the Maker Focus radios are not working with autoack, despite the manufacturer's claim they do?
I could imagine that this is a difference between the nrf24l01+ and the non ‘+’ version of the basic chip. You can test if the suspect module has a non ‘+’ version by attempting to get it to talk to the others with the data rate set to 250 kbps. This rate is supported by the ‘+’ version only.
The Maker Focus radios have an external antenna and the Addicore's do not.
They have different power requirements, the + has a power amplifier.
【NRF24L01+ Module】High-performance wireless data transmission chip NRF24L01 +, an increase of high-power PA and LNA chips, RF switches, band-pass filters and other professional full bidirectional RF, making the effective communication distance has been greatly expanded.
Do you have a 10uF cap across the powersupply pins of the NRF.
Can you please post a copy of your circuit, in CAD or a picture of a hand drawn circuit in jpg, png?
Do you have a DMM to measure the supply voltage at the NRF when they are activated?
Just to be clear. The '+' is a Nordic Semiconductors designation. That is there are two versions of the chip NRF24L01 and NRF24L01+. The links are to the separate data sheets.
Not all features are supported by the non '+' chip, for example the low data rate RF24_250KBPS is not available.
Some module vendors also use the term "NRF24L01+PA+LNA" to indicate that the board has, in addition, a combined power amplifier and low noise amplifier chip (usually RFAxis X2401C).
That a 10uF and 100nF capacitor close to the power rails of the board is good.
That if lowering the radio transmitter power ( RF24_PA_MIN ) makes the problem "go away", then a power supply / decoupling issue should be suspected. Lowering the radio power here is only a troubleshooting measure and not a solution.
Sorry for the slow response. I've been busy with other issues these last few days.
Do you have a 10uF cap across the powersupply pins of the NRF.
I did not have the cap across the power pins on the NRF. This seemed to have solved the problem. Thank you very much Tom George. A schematic would not have helped much as it's just the radios connected to the different boards, nothing else.
That a 10uF and 100nF capacitor close to the power rails of the board is good.
Do I need to have a 100nf across the power supply? This leads me to some questions about capacitors across other devices. Should I have one on all the individual components such as RTC's and relays such as these?
If so, how do I determine the value required? I am not an electronics expert, but I do love tinkering with these projects. I learned from Perry Bebbington in the display forum I needed a 47uf across my Nextion display.
Do I need to buy an expensive oscilloscope?
Thank you all for your expertise. I can now incorporate these radios into a more complicated project I have going. I'm really glad these forums exist and grateful for the people who dispense advise such as yourselves.
The larger value capacitors, in this case 10uF, have the effect of smoothing the supply, compensating for higher instantaneous demand of devices like radio modules. The lower value capacitors, say 100nF, are to decouple one device from others, reducing higher frequency noise. Especially decoupling capacitors should be as physically close to the device as possible.
By board power rails, I was referring to the board of the radio module. Ideally, modules should have their own adequate decoupling and smoothing capacitors. For some components, especially ICs, it is good when they each have their own external decoupling capacitors.
Those relay modules you have linked to should not need additional capacitors.
Generally, an oscilloscope is more useful for troubleshooting and verifying the performance of analog circuits. It should not be necessary if you are working mainly with digital circuits and properly designed modules.
6v6gt:
The lower value capacitors, say 100nF, are to decouple one device from others, reducing higher frequency noise. Especially decoupling capacitors should be as physically close to the device as possible.
What exactly does decoupling mean in the electronic circuit design world?
As has already been pointed out, there are a number of "clone" NRF24L01+ chips in existence. Maybe new, poor quality ones are emerging which may explain the number of problems people have with these devices.
Some, like the one known as Si24R1 (which can also carry the markings similar to a genuine Nordic Semiconductors NRF24L01+) exhibit a problem with handling acknowledgements. But different "clones" can exhibit different behaviour.
