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danak6jq / RAK3172

Port of STM32WLxx example for RAK3172
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HSEO is 32M? #3

Closed IoTopenTech closed 2 years ago

IoTopenTech commented 2 years ago

I'm trying to understand this port. The IOC file shows an 8M HSEO but, according to the RAK3172 datasheet, it should be a 32M one. imagen I don't know whether this is relevant, but would like to understand it. Kind regards from Madrid

IoTopenTech commented 2 years ago

According to this forum post (https://forum.rakwireless.com/t/hse32-tcxo-or-xtal/4764/7) it seems to be a 32MHz regular (no TCXO) crystal

danak6jq commented 2 years ago

That's correct, and an RAK hardware feature

danak6jq commented 2 years ago

The chip is a little confusing in how the clock is set up. It's apparently actually running in the radio and fed to the MCU, and doesn't follow the usual rules for configuration.

DominusFulguris commented 2 years ago

The .ioc file still set to 8MHz for the HSEO.

I think the clock config should be 32MHz for HSE, then PLL Source Mux set to HSESystem Clock Mux to PLLCLK. PLLM values /2, X6, /2

Or have I got this mixed up somehow?