Spirit1 - External Clock from MCU or using Low Power Oscillator

[jacopo]

Posted on July 02, 2015 at 13:13

Greetings,

I have a problem with my test board. I am using a Spirit1 module on a PCB toghether with a STM32F103 microcontroller, trying to implement a wireless comunication. On the board there are two different oscillators: a 8 MHz quartz oscillator for the microcontroller and a 52 MHz quartz for the Spirit1. The problem is that I found out that the XIN and XOUT pins of the Spirit1 are not connected to the 52 MHz oscillator, so the module stays in READY state after exiting from shutdown. I wanted to know if:

- it is possible to configure the low frequency  internal oscillator (at 34.7 kHz) of the Spirit1 as the reference clock;

- it is possible to eventually generate an external clock coming from the MCU (for example through a PWM) to one of the GPIOs of the Spirit1.

Thank you for your attention.

[Nickname4815_O]

Posted on July 06, 2015 at 09:42

Hi,

- it is not possible to configure the RC osc as ref clock. Indeed it is a low frequency clock (34.7kHz) and it is not possible use it as a PLL reference.

- from GPIO it is only possible to supply the low frequency clock (in replacement of the internal RC) and, as said such reference can't be used as ref.

So, I am scared that the only solution is to redo the board or even try to connect the XTAL to the XIN XOUT pins .

Best Regards,

F.

[jacopo]

Posted on July 07, 2015 at 13:11

I thought so. Thank you for your attention, at least now I cleared all my doubts about it.