What uart port connects to the modem on the B-L462E-CELL1 board?

JVand.12 · ‎2023-05-20

KDJEM.1 · ‎2023-05-24

Hello @JVand.12 ,

The USB connector is used to connect the UARTs of the modem to debug and update the modem in LBAD0ZZ1SE.

The " CN10" is a USB connector for UART. Indeed, the CN10 is connected to UART1 and UART2 through USB-UART converter. These connections are well descripted in the MB1508-L462RE-C03 Board schematic in Sheet 5.

For more explanation, I advise you to refer to UM2743 and precisely Hardware layout and configuration Section and USB connector for UART Section.

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Kaouthar

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JVand.12 · ‎2023-05-24

To clarify, I am asking about the UART connection that is used by the low level code to tx/rx data via the cell modem. Digging into the setup code for the driver I discovered that the MCU transmits data to Port A, GPIO4, and receives on Port C, GPIO5. There is a unique wakeup step and so ordinary UART code will fail. Due to the bugs I encountered with handling of sockets I am entertaining creating my own driver.