STM32WL55xx Custom Board Development
Hi ST,
I have developed and manufactured a custom STM32WL55CCU6 target based board, based on the reference board STDES-WL5U4SBB you provided, and I noticed the following issue:
when I uploaded my application that I have uploaded and tested before on the NUCLEO-WL55JC1 Board with region configuration LORAMAC_REGION_US915, I found that the gateway receives only on the uplink sub-channel Band 64 which has a bandwidth 500KHz, although the same application uploaded and executed successfully on the board NUCLEO-WL55JC1 and connected with all other sub-channel Bands with band width 125KHz.
In the Board NUCLEO-WL55JC1 based on the target STM32WL55JC17 I Found in the schematic that it has 2 External Oscillators: (TCXO 32MHz and the default HSE 32MHz Oscillators) and the application running on the NUCLEO-WL55JC1 used the TCXO Oscillator, while the other board I developed based on the STDES-WL5U4SBB board has no TCXO (as the reference provided)
So my questions are:
Q1: What could be the reason of this problem? Knowing that I also configured the default HSE instead of the TCXO on the Board NUCLEO-WL55JC1 and it also worked well.
Q2: I’m developing now another board based on the target STM32WL55JC17 and following the reference of the NUCLEO-WL55JC1 Board, Should I Keep both the Crystal as the NUCLEO or remove one of them and which one to remove?