PaulS:
You need 4 bytes in the array to hold the 4 bytes you need to send and receive. But, you are not sending decimal values. That implies floating point variables, not ints.
You can convert the floats you have to ints, as you are doing, use highByte() and lowByte(), or bitshifting and masking, to convert the signed and unsigned ints to bytes, stuff the bytes into the 4 elements of the array, send and receive the array, and then use bitshifting, or multiply by 256 and addition to recreate the ints that you can then convert back to floats.
Got it working now with your advice PaulS. Thank you so much! Now by sending temp and humidity on the same message I can save some current from my battery because I do not have to do a separate transmit with the humidity reading.
I did this on the TX side when constructing the RF message:
myMsg.cmd = 0x03; // Return Data
myMsg.idx = 0x05; // HID and Sensors
myMsg.sdx = 0x0a; // Temperature & humidity
myMsg.data[0] = highByte(t);
myMsg.data[1] = lowByte(t);
myMsg.data[2] = highByte(h);
myMsg.data[3] = lowByte(h);
myMsg.len = 4; // Update length
sendMessage();
And this on the RX side to pick up the values for logging later on to an external RRD database:
kitchentemp = myMsg.data[0] * 256 + myMsg.data[1];
kitchenhum = myMsg.data[2] * 256 + myMsg.data[3];
Cheers!