Missing pull-up resistors on MISO? (No – SPI uses push-pull). Real Cause: You forgot to connect the CE pin to a digital output. CE must be pulled HIGH for TX mode. Many beginners leave it floating. Tie it to a terminal set to HIGH or connect it to the Arduino pin 9 as shown above.

Here’s a clean, helpful write-up you can use for a blog, GitHub README, or forum post (like Embedded Related, EDAboard, or Reddit).