nRF24LU1+ WRSR command not working, cannot erase InfoPage

[kelin]

I have a USB dongle with nRF24LU1+ chip (marking "NRF E LU1P16 1438AD").

I have several problems with programming this chip via SPI. For example after entering programming mode, I call WRSR with bytes 00100000 (FSR.WEN). Then I'm trying to check the result with RDSR and I'm getting 00000000, why?

Also I try to erase InfoPage with FSR set to FSR_WEN | FSR_INFE followed by ERASE_PAGE command. Then I read this page to check if erase operation was successful, and I get the next sequence. 416 0x00 and 96 0xFF bytes.

All this seems weird to me. I suppose this is not a OTC chip. May be it's broken?

Dongle: (pins: VDD, PROG, SCK, MOSI, MISO, CSN, GND).

Flasher: (I use Arduino Due or Teensy)

Schematics:

[Hung Bui]

@Kelin: I'm not sure what could be wrong here, but have you made sure you followed the instruction in the spec :

To allow access through the SPI the external PROG pin must be set high during all flash operation commands. After activation of the PROG pin you must wait at least 1.5 ms before you input the first flash command.

Also please provide a close up photo of your setup.

[kelin]

@Hung Bui, my program wait 5 seconds after pulling PROG pin high. But, there one little problem, my dongle has no RESET pin, but documentation says that it's required for entering programming mode. I added pictures to my question.

[Hung Bui]

Hi Kelin,

I'm not sure the RESET pin is needed. The instruction at 17.7.3 only tells the RESET pin should be connected to pull up and only needed if you want to reset the chip after programming (which can be done by power reset). Do you have the schematic of the board, have you made sure RESET pin is pulled high ?

Also I would suggest not to use too long cables on the SPI lines. Should be less than 15cm. Have you tried to write to a normal flash address instead of the Infopage ?

[kelin]

I added schematics which was provided by seller. It's not very detailed but it is enough to see that RESET is pulled to VDD through the resistor above the SCK hookup.

[Hung Bui]

@kelin: Have you tried to write to a normal address instead of the Infopage ? Do you have a logic analyzer ? Could you send the SPI trace ?