USB communication with other module

[Venus_Bilandi]

Hi, I have a nRF52840 based Custom development board and a GSM module(AT command based) with UART and USB support. Because of lack of UARTs in nRF52840, I want to use USB to transmit AT commands and receive response.

How do I do that?

[Simonr]

Hi

From what I understand, you are out of UART instances to use, correct? And thus you want the GSM module and the nRF52840 to connect over USB. USB has a strict master/slave protocol for addressing peripheral devices, and two peripheral devices can not interact with one another directly except via a host. The nRF52840 is not able to act as a USB host, and I would assume the GSM module is not either. Making this connection require a USB host to manage the communication.

Are any of the other UART devices your nRF52840 able to communicate over I.E. SPI or I2C, if so I would recommend switching to that to free up a UART instance for your GSM module.

Best regards,

Simon

[Venus_Bilandi]

Pendrive is also a USB device(peripheral) so how does nRF52840 is able to perform a firmware update using pendrive.

How it is communicating with the pendrive?

[Simonr]

Can you provide some more details on this pen drive (what device exactly is it) and how you're doing firmware updates to it? Are you doing them over BLE, USB, UART or what? And how are the pen drive and nRF52840 connected? If both are connected to a computer they can communicate via the USB host on the computer for example.

Best regards,

Simon

[Venus_Bilandi]

What is USB bootloader in the SDK?

How Can I use it to update the Firmware?

Can I use a pendrive or I nedd a Host computer or a mobile phone for that?