Burning Bootloader with other SPI device attached

In the pdf file attached, you can see I have an Atmega328P and an NRF24L01+ transceiver in the project. I need to burn the boot loader on the Atmega328P. Can I do it directly on my custom PCB, with the NRF24L01 installed. It uses SPI. Along with the MOSI, MISO, & SCK pins, it has 2 other pins connect to the Atmega328P. CE & CSN, are connected to D7 & D8. CSN on the NRF24L01+ is the chip select pin. This shouldn't be a problem, should it?
thanks.

NRF24L01+Atmega328P-AU.pdf (41.6 KB)

Maybe. :slight_smile: SPI devices are supposed to be high-impedance when their chip-select line is not active. Some don't do too well with that (e.g. the TLC5940). Some do. The datasheet sometimes spells out what the device does when chip-select is not active.

So, if the NRF24L01+ transceiver really does set its SPI pins to high-impedance then you are good-to-go.

However, in your schematic there is no pullup resistor on CE. If there is not a pullup somewhere on that line (e.g. internal to the NRF24L01+ transceiver) then you will have to add one.

Series resistors (220 ohm is a good choice) on the three SPI lines will protect all parties in the event of a mistake.

I guess I'll just play it safe and get a TQFP32 socket adapter, and burn the boot loader before populating the PCB, then.
Thanks.