stm32h7-sdmmc

Hardware Abstraction Layer for 'Secure' digital input/output MultiMediaCard interface (SDMMC) on the STM32H7.

This crate depends on the GPIO and Clock functionality from stm32h7xx-hal.

SDMMC

The H7 has two SDMMC peripherals, SDMMC1 and SDMMC2.

IO Setup

For high speed signalling (bus clock > 16MHz), the IO speed needs to be increased from the default.

use stm32h7xx_hal::gpio::Speed;

let d0 = d0.set_speed(Speed::VeryHigh);

Usage

By default the SDMMC bus clock is derived from the pll1_q_ck. This can be set when initialising the RCC.

let ccdr = rcc
    .pll1_q_ck(100.mhz())
    .freeze(vos, &dp.SYSCFG);

There is an extension trait implemented for the SDMMC1 and SDMMC2 periperhals for easy initialisation.

// Create SDMMC
let mut sdmmc = dp.SDMMC1.sdmmc(
    (clk, cmd, d0, d1, d2, d3),
    ccdr.peripheral.SDMMC1,
    &ccdr.clocks,
);

The next step is to initialise a card. The bus speed is also set.

if let Err(err) = sdmmc.init_card(10.mhz()) {
    info!("Init err: {:?}", err);
}

The card() method returns useful information about the card.

let card = sdmmc.card();
if let Some(card) = sdmmc.card() {
    info!("SD Card Connected: {:?}", card);
}

License

Licensed under either of

Apache License, Version 2.0 (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)

at your option.

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.