On the product page for ZED-X20P Qwic it indicates ‘The USB interface does not fully comply with industry standards and is unsuitable for production use. The USB 2.0 FS (full speed, 12 Mbit/s) interface can be used for host communication. Due to the hardware implementation, certifying the USB interface may not be possible.’ I am a loss to know how limiting this would be for configuring the receiver or obtaining data from it. I noticed that on the documentation for the ublox EVK-X20P evaluation kit, it has the same warning as the Sparkfun board, plus further ‘We recommend using USB-A to USB-C cable only. USB-C to USB-C type cable is not supported.’ The ublox kit has USB C at the receiver end and expects USB A to connect to a port on a computer with u center 2. So are these warnings likely to vanish once the certifying agencies get a chance to test ZED-X20P or did ublox maybe make a hardware mistake to be corrected in later chip versions? There are unfortunately no reviews yet for the Sparkfun kit that might give information about USB issues. Thanks for any insight ..
Welcome snowbank!
You should ask u-blox as well for the official response, but this is how I’ve experienced it:
The X20P connects just fine over USB, just like its previous model (F9P). You can communicate and configure the device over USB, with the one caveat that you cannot update the firmware over USB (we’ve tested UART and I2C upgrades just fine). We believe the warnings and language coming from u-blox is because there was an issue with the IC where USB is not fully functioning. Again, this is just me, but u-blox is a very conservative company - if it’s not perfect, it doesn’t ship. So since USB is not performing completely (in some way I am not privy to), they don’t wany users to use it. Perhaps there will be a revision to the silicon in the future, but for now, USB works great for bench and project use. If you’re deploying a X20P based product across a global fleet, then I would design the system to use one of the other many interfaces to communicate with the module: UARTs, I2C, or SPI and leave USB as a ‘nice to have’ but not critical.
@snowbank : u-blox have just released further information about this: