So I have project, in which i'm trying to use nrf24l01 and max7219 chip on the same SPI bus, but i've achived nothing. I was wondering if you could help me with this, because it's propably nothing difficult. I think that if i'd use nrf24l01 "normally" with CE CSN on pins 7, 8 and max7219 with SS on pin 10, and MOSI and SCK pins in parallel it could work, am i right?
They should both work on the same bus, with SCK, MOSI, MISO in parallel, and with unique chip select pins (say 10 and 9).
nrf24L01 might need 5V to 3.3V buffer on SCK, MOSI, CS (and it has CE line also?), a cd74HC4050 powered from 3.3V is good for that, and then 1 gate of 74HC125A to buffer MISO from 3.3V back to 5V, with the nrf24L01 chip select used to control the '125A OE signal.
I use the same for controlling 3.3V SD cards.
The thing to watch for is the SPI modes the nrf24L01 needs. MAX7219 works fine with the default settings of 4 MHz clock, MSBFIRST, SPI Mode 0. I don't know about the nrf24L01. Do some reading; you may have to switch modes back and forth.
CrossRoads:
nrf24L01 might need 5V to 3.3V buffer on SCK, MOSI, CS (and it has CE line also?),
The nRF24 modules normally used with Arduinos can accept 5v inputs but they must be powered by a max of 3.6v - 3.3v being the usual.
@kubasz091, I assume your nRF24 works perfectly when it is the only SPI device. If not, make sure to get that working first.
Thank you both for your replies! I'll write later, if I get some problems or not.