custom write ack payload.

[ulao]

My end goal for development is something like the following.

Master sends 0x00 slave sends back 13 bytes of data.
Master sends 0x01 slave sends back one byte of data.
Master sends 0x02, 0x03, 0x04 slave calls a function with parm (3,4)

My plan is to send the data with disabling auto ack from the master and then going in to receive mode, and having the slave return the data by going in to  transmit mode. Though I was wondering if any of that can be automated with a custom ack?

EDIT: Ok just read this on the net.

"This acknowledgement message can contain a preloaded payload, meaning a system of bi-directional communications can be established entirely using a master device that transmits data requests to each slave device in succession. The nRF24L01+ does this by storing a preloaded message into its transmit First-In-First-Out (FIFO) buffer, and sending this message on the listening pipe address as soon as a message with ack payload requested is received."

If that sort of thing is possible, is there a small example or write up on that? Can a "preloaded message" be dynamic?

[Håkon Alseth]

Hi,

  

My plan is to send the data with disabling auto ack from the master and then going in to receive mode, and having the slave return the data by going in to  transmit mode. Though I was wondering if any of that can be automated with a custom ack?

 As you mention, you can do this with using auto ACK, and ACK payload.

To ensure that you receive the data, it is recommended that you send a "prepare ACK payload" command first to allow the host to upload it to the FIFO, then a dummy payload to fetch the actual ACK payload.

If that sort of thing is possible, is there a small example or write up on that? Can a "preloaded message" be dynamic?

 What do you mean by "dynamic"? You can upload a ACK payload on a specific pipe, and on the next received payload on that specific pipe, the ACK will then be sent with your ACK payload.

 

Kind regards,

Håkon

[ulao]

Sounds straight forward. But as soon as I enable ackpayload or dynamicpayload I can no longer receive. Also noticed since I have been working with this my master needs to have tx and rx both set to the same address. (0x30 and 0x2a) IF not it will not send. I never understood that.

master short code

0x20,0x0A
0x25,2
0x26.0x0E
0x23,3
0x3D,6
0x22,0x3f
0x30,1,1,1,1,1
0x2a,1,1,1,1,1
pulse

0xa0, 0xff send payload ready flag
0xa0, 3 test code
pulse

receiver
This is an Arduino so I do not know what it is really doing but here is the output.

STATUS         = 0x0e RX_DR=0 TX_DS=0 MAX_RT=0 RX_P_NO=7 TX_FULL=0
RX_ADDR_P0-1     = 0x0101010101 0c2c2c2c2c2
RX_ADDR_P2-5     = 0xc3 0xc4 0xc5 0xc6
TX_ADDR         = 0x0101010101
RX_PW_P0-6     = 0x01 0x01 0x00 0x00 0x00 0x00
EN_AA         = 0x3f
EN_RXADDR     = 0x03
RF_CH         = 0x02
RF_SETUP     = 0x0f
CONFIG         = 0x0b
DYNPD/FEATURE     = 0x03 0x06 <--- with this set I never receive data. with 0,0 I do.
Data Rate     = 2MBPS
Model         = nRF24L01+
CRC Length     = 8 bits
PA Power     = PA_MAX

[Håkon Alseth]

Hi,

 

ulao said:

Do I need to clear bits or flush because I write the new payload? 

 It sounds like your firmware isn't clearing the events (TX_DS, RX_DR, MAX_RT). I do not know details about the library you're using or how it works in the deep, unfortunately. Its quite normal that libraries, even arduino, clears these when needed.

 

ulao said:

when I send the same data this happens, so I think the counter int is not resetting on same data sends. This is a know issue on this chip (china clone) ill buy elsewhere. -a suspicion only-

 Could you share the chip markings of your device (take a picture of it for instance) so I can check it with known clone?

 

ulao said:

What woudl it mean when my status registers goes from 2e to 3e?
to get my payload I just send NOP commands and read the status register. Normally it goes to a 0x60 around 300 us. But there are times it goes to 0x3e and my data is not ready. I'm not sure what is doing this. I make sure to first clear my ints before sending with

If it goes from 0x2x to 0x3x,  It means that it the 4th bit is set, which is MAX_RT, ie: your receiver isn't responding.

 

Kind regards,

Håkon

[ulao]

...

[ulao]

[Håkon Alseth]

Hi,

 

1808AH is unfortunately a known fake revision, which can explain the strange behavior you're seeing.

Kind regards,

Håkon

[ulao]

I assume this chip woudl be correct?

www.mouser.com/.../nRF24L01P-R7

I'm not able to find a dev board that matches what I have.

[Håkon Alseth]

Hi,

 

Yes, mouser is one of the online dealers that distributes our devices.

You can plot in your region/country here, to see which alternatives are available in terms of distributors in your area:

https://www.nordicsemi.com/About-us/FindDistributor

 

As for a genuine module, try for instance sparkfun. Or if you have soldering tools, take it off the current module and solder on a genuine one.

 

Kind regards,

Håkon