DFR0941: 40 pin GPIO header signals
PAVLO.YADVYCHUK 2026-01-22 06:24:23 21 Views1 Replies Hi folks,
does anyone have pinout info for 40pin GPIO header on DFR0941 DAC?
I can understand this:
pin12 → GPIO18 → PCM CLK → PCM9211_IO.C1
pin35 → GPIO19 → PCM FS → PCM9211_IO.C2
pin40 → GPIO21 → PCM DO → PCM9211_IO.C3
but the last one is
pin29 → GPIO05 → ??????? → PCM9211_IO.C0
I'd expect this should be configured as “ALT0 FUNC” → GPCLK1, is my understanding correct?
Don't we need some DTB overlay for this? If yes, which one?
Are any other pins (except power supply) in use?
thanks in advance.
Hi! You don't need to worry about any unexpected remapping. The DFR0941 (MAX98357A) is a standard I2S DAC, which means it only utilizes the Raspberry Pi’s dedicated PCM/I2S pins:
GPIO 18: PCM CLK
GPIO 19: PCM FS (LRCK)
GPIO 21: PCM DIN (Data)
Pin 29 (GPIO 5) is completely untouched by this board and will function as a standard GPIO by default.
While GPIO 5 can be used for GPCLK1, the DAC’s driver won't enable that function automatically. If you need GPCLK1 for another part of your project, you'll just need to configure it manually in your config.txt or via a device tree overlay.
so, everything except the three PCM pins mentioned above remains available for your use as standard GPIOs.
For the exact pin mapping and driver setup, you can check the official DFRobot Wiki: DFRobot MAX98357A Amplifier Wiki
Oliver.Taylor 
