nRF24LU1+ Programming Through USB

[cyaoplus]

Hi,

I have successfully flashed nRF24LU1+ via ISP. Right now, I am validating using USB to download firmware for future production.  Here is the issue.

Our project has a USB hub chip connected to two nRF24LU1+ chips.  I have flashed one of  the nRF24LU1+ with boot24lu1p-f32.hex which I found in SDK. When I connect our board to PC USB, Windows Device list recognized the unflashed  chip as USB Receiver.

In nRFgo Studio, only flashed nRF24LU1+ chip can be recognized.  Therefore, the unflahsed one cannot use USB to download. I read from spec that nRF24LU1+ has factory bootloader.  I am wondering why this issue happens. Thank you for answering.

[Håkon Alseth]

Hi,

 

I suspect that the device "USB Receiver" has already been programmed once before.

When delivered from Nordic, each nRF24LU1+ will have the USB bootloader present in flash and will enumerate as a bootloader device.

The USB bootloader is made as an option for mass-production, and is considered "lost" once you have used it for programming once.

 

It is possible to read out the USB descriptor strings in your device manager, where you can see the identifiers for the specific "USB Receiver" device.

 

Best regards,

Håkon

[cyaoplus]

Hi Håkon,

 

Thank you for your reply.  I am sure I haven't flashed the "USB receiver" chip before. Actually all the 20 pcs chips I got were named as "USB receiver" in device list. However,  it may has possibility that I got used chips from the supplier. What is the correct or official name for nRF24LU1+ with original bootloader shown in device list?

[Håkon Alseth]

Hi,

 

A "blank" nRF24LU1+ should enumerate as either "nRF24LU1P-F32 BOOT LDR" (typical to get via windows update) or "nRF24LU1+ Bootloader" (newer driver, supplied with nRFgo Studio) depending on which driver is loaded.

The first one is the older libusb-0.1 driver, while the "nRF24LU1+ Bootloader" is the libusb-1.0 driver.

 

Kind regards,

Håkon

 

[cyaoplus]

Hi Håkon,

Thanks for answering. Then I suspect  I got used parts.