I am referencing to this example:
https://github.com/raspberrypi/pico-exa ... ello_48MHz
When I am adding lines 49 to 66 to my C-Code, my Pico W does not connect to the WiFi anymore.
Lines 49-66:
This is what I am seeing on the serial port when I am NOT adding those lines.
This is what I am seeing on the serial port when I am adding those lines (including the header files of course).
I tried with a variant of the above, output on the serial port is the same.
So why does this not work? Why CYW43 does not like diminishing clk_sys?
I am not really familiar with the Pico W, but according to the documentation the CYW43439 driver makes use of one of the PIOs, so the PIO cannot deal with a changed clk_sys? Or what is the matter here?
With the "normal" Pico I've never seen any problems with changing clk_sys, and as one would expect the power consumption goes down when the system clock goes down (what is actually the reason I want to change it).
https://github.com/raspberrypi/pico-exa ... ello_48MHz
When I am adding lines 49 to 66 to my C-Code, my Pico W does not connect to the WiFi anymore.
Lines 49-66:
Code:
clock_configure(clk_sys, CLOCKS_CLK_SYS_CTRL_SRC_VALUE_CLKSRC_CLK_SYS_AUX, CLOCKS_CLK_SYS_CTRL_AUXSRC_VALUE_CLKSRC_PLL_USB, 48 * MHZ, 48 * MHZ); // Turn off PLL sys for good measure pll_deinit(pll_sys); // CLK peri is clocked from clk_sys so need to change clk_peri's freq clock_configure(clk_peri, 0, CLOCKS_CLK_PERI_CTRL_AUXSRC_VALUE_CLK_SYS, 48 * MHZ, 48 * MHZ); // Re init uart now that clk_peri has changed stdio_init_all();Code:
clock_configure(clk_sys, CLOCKS_CLK_SYS_CTRL_SRC_VALUE_CLK_REF, 0, 12 * MHZ, 12 * MHZ); // Turn off PLL sys for good measure pll_deinit(pll_sys); // CLK peri is clocked from clk_sys so need to change clk_peri's freq clock_configure(clk_peri, 0, CLOCKS_CLK_PERI_CTRL_AUXSRC_VALUE_CLK_SYS, 12 * MHZ, 12 * MHZ);I am not really familiar with the Pico W, but according to the documentation the CYW43439 driver makes use of one of the PIOs, so the PIO cannot deal with a changed clk_sys? Or what is the matter here?
With the "normal" Pico I've never seen any problems with changing clk_sys, and as one would expect the power consumption goes down when the system clock goes down (what is actually the reason I want to change it).
Statistics: Posted by FlorianJW — Fri Jan 16, 2026 5:24 am