Sending large structs via nrf24l01 leads to cliping of some structs members I started with building of the wireless temp/hygro/other values probes. I use 2 arduinos, both with nf24l01+ wireless transceivers, library used is rf24.h (https://github.com/maniacbug/RF24). Basically ping/pong test works for me - so each arduino communicates properly via nrf24l01+.
I added dht22 temperature sensor and just for testing I started with sending structure:

typedef struct{
  int A; // just counter to see if receiving new data
  float B; // temperature
} data;

data payload;


I send it from Arduino1 like this:

radio.write( &amp;payload, sizeof(payload) );


Other Arduino2 receives the payload:

radio.read( &amp;payload, sizeof(payload) );


This works perfectly and I am able to print the counter value as well as the temperature value on the oled display o Arduino2. The problem is when I add float C to the struct for sending/receiving hygrometer values. Then Arduino2 does not receive/display any valid hygro value, but there is just value of 0.00.

I think I know where my problem is - nrf24.h has possibility to set payload size for nrf24l01+ - both Arduinos have to use the same payload size (default is 16, min is 8, max is 32). I use 8 - as this looks to be the most reliable value when using larger distances between Arduinos.
When I tried to set payload size to 32 on both Arduinos:

radio.setPayloadSize(32);


Then it works and I can receive and display counter, temp, hygro values.
So it looks the nrf24l01+ sends a payload of either 8 or 32 bytes and when sending struct with INT, FLOAT, FLOAT - 8 bytes is not sufficient and 32 bytes of payload is needed. But when I will use many other values, I can reach also limit of 32 bytes payload.

I do not have much skills in C programming and also I do not fully understand how data packets are being transferred between nrf24l01+ modules- maybe I just need to adapt my send/receive code to handle sending of the larger structures. Maybe somebody could give me a hint.
Your payload is too big. You will have to split it to smaller pieces.

NOTE: If you'd use a library like RF24Mesh then you'd not have to worry about it.