nRF24L01 Ack issue / tx giving max_rt error / PIC18F25K20

RE: nRF24L01 Ack issue / tx giving max_rt error / PIC18F25K20

Hung Bui — Mon, 24 Jul 2017 10:13:05 GMT

Do you have full control of the code ? I would assume CE is controlled by the MCU ?

What I'm saying is that if you enable the radio, send 1 packet, then disable and enable the radio and send the same packet, the RX will misunderstood that it's a re-transmission and ignore the packet.

If you send packet continuously without disable and enable the radio, the PID will be flipped for each packet and then the RX can detect that they are new packets.

If you want to send packets and disable then enable radio, you should add 1 more byte/bit into the payload and change that bit so that each packet would have different payload.

RE: nRF24L01 Ack issue / tx giving max_rt error / PIC18F25K20

Jev — Fri, 21 Jul 2017 12:18:16 GMT

Yes, No is CE HIGH before sleep and LOW when in sleep and PWR_UP low. Not sure, might be. As the module is shielded I cannot check it, unless to open it. I will probably do it on Monday.

If I am sending continuously, it works fine. And receives every-time I am sending even without changing the packet content.

RE: nRF24L01 Ack issue / tx giving max_rt error / PIC18F25K20

Hung Bui — Fri, 21 Jul 2017 12:10:20 GMT

Have you made sure you set CE = 0 or set PWR_UP = 0 before you cut the power ? Could be that the 16Mhz crystal still running.

My suggestion is to keep sending (more than 2 time) before you switch mode or doing anything else, just try sending continuously, just for testing. Try to change the content of the data on every packet.

RE: nRF24L01 Ack issue / tx giving max_rt error / PIC18F25K20

Jev — Fri, 21 Jul 2017 07:47:10 GMT

Hung Bui ,

Yes, DPL enabled on both ends. Yes, Radio powered only for a moment. Everytime it is powered it going through configuration routine and then transmission with some delays before and after. So, instead of putting to sleep, I am disconnect the power to radio module as I found even in sleep the module ( nRF24L01 with PA LNA) consumes quite a lot of current (around 1mA) for my application.

Oh, I see... yes, I am sending same packet twice, but loading it to buffer every time I am transmitting.

[code]

    for (a = 0; a < 2; a++)
    { 
        Transmit_nRF24L01_TX(); 
    }

[/code]

So if i am replacing a < 2 with a < 1, it transmits ones and receives max_rt error

RE: nRF24L01 Ack issue / tx giving max_rt error / PIC18F25K20

Hung Bui — Tue, 18 Jul 2017 13:47:30 GMT

You need to enable DPL on both side so that the receive also know that the packet length is dynamic and it should check for the NOACK bit.

Do you mean you transmit and then you disable the radio and then transmit again ?

If you do that and don't change the content of each packet you send, the RX will think that it's a re-transmission (because PID doesn't change, content doesn't change) and ignore them.

If you send 2 or more packets in a row, the PID will change, and the RX can recognize that it's a new packet.

RE: nRF24L01 Ack issue / tx giving max_rt error / PIC18F25K20

Jev — Tue, 18 Jul 2017 09:35:40 GMT

Hung Bui,

I have tried both DPL enabled and disabled with no luck, at the minute DPL is enabled. Why it should be enabled on both sides? As one works as transmitter another side as receiver only (not taking in account ACK) TX_DC is received only when two messages send one after another. If one packet sent no TX_DS received.

RE: nRF24L01 Ack issue / tx giving max_rt error / PIC18F25K20

Hung Bui — Fri, 07 Jul 2017 15:18:32 GMT

Hi Jev,

I'm not so familiar with the nRF24L01 , but have you enabled DPL, Dynamic payload length ? on both side ? Do you receive any TX_DS on the PTX ? (and the PRX if you do ack payload ?)