//! # Pico SD Card Example //! //! Reads and writes a file from/to the SD Card that is formatted in FAT32. //! This example uses the SPI0 device of the Raspberry Pi Pico on the //! pins 4,5,6 and 7. If you don't use an external 3.3V power source, //! you can connect the +3.3V output on pin 36 to the SD card. //! //! SD Cards up to 2TB are supported by the `embedded_sdmmc` crate. //! I've tested this with a 64GB micro SD card. //! //! You need to format the card with an regular old FAT32 filesystem //! and also make sure the first partition has the right type. This is how your //! `fdisk` output should look like: //! //! ```text //! fdisk /dev/sdj //! //! Welcome to fdisk (util-linux 2.34). //! Changes will remain in memory only, until you decide to write them. //! Be careful before using the write command. //! //! Command (m for help): Disk /dev/sdj: //! 59,49 GiB, 63864569856 bytes, 124735488 sectors //! Disk model: SD/MMC/MS/MSPRO //! Units: sectors of 1 * 512 = 512 bytes //! Sector size (logical/physical): 512 bytes / 512 bytes //! I/O size (minimum/optimal): 512 bytes / 512 bytes //! Disklabel type: dos //! Disk identifier: 0x00000000 //! //! Device Boot Start End Sectors Size Id Type //! /dev/sdj1 2048 124735487 124733440 59,5G c W95 FAT32 (LBA) //! ``` //! //! The important bit here is the _Type_ with `W95 FAT32 (LBA)`, other types //! are rejected by the `embedded_sdmmc` filesystem implementation. //! //! Formatting the partition can be done using `mkfs.fat`: //! //! $ mkfs.fat /dev/sdj1 //! //! In the following ASCII art the SD card is also connected to 5 strong pull up //! resistors. I've found varying values for these, from 50kOhm, 10kOhm //! down to 5kOhm. //! Stronger pull up resistors will eat more amperes, but also allow faster //! data rates. //! //! ```text //! +3.3V //! Pull Ups ->|||| //! 4x[5kOhm] //! ||| \ //! _______________ ||| \ //! | DAT2/NC 9\---o|| \ _|USB|_ //! | S DAT3/CS 1|---o+----+------SS--\ |1 R 40| //! | D CMD/DI 2|----o----+-----MOSI-+-\ |2 P 39| //! | VSS1 3|-- GND | | | GND-|3 38|- GND //! | C VDD 4|-- +3.3V | /--SCK--+-+----SPI0 SCK-|4 P 37| //! | A CLK/SCK 5|---------+-/ | \----SPI0 TX--|5 I 36|- +3.3V //! | R VSS2 6|-- GND | /--MISO-+------SPI0 RX--|6 C | //! | D DAT0/DO 7|---------o-/ \------SPI0 CSn-|7 O | //! | DAT1/IRQ 8|-[5k]- +3.3V | | //! """""""""""""""" | | //! | | //! ......... //! |20 21| //! """"""" //! Symbols: //! - (+) crossing lines, not connected //! - (o) connected lines //! ``` //! //! The example can either be used with a probe to receive debug output //! and also the LED is used as status output. There are different blinking //! patterns. //! //! For every successful stage in the example the LED will blink long once. //! If everything is successful (9 long blink signals), the example will go //! into a loop and either blink in a _"short long"_ or _"short short long"_ pattern. //! //! If there are 5 different error patterns, all with short blinking pulses: //! //! - **2 short blink (in a loop)**: Block device could not be aquired, either //! no SD card is present or some electrical problem. //! - **3 short blink (in a loop)**: Card size could not be retrieved. //! - **4 short blink (in a loop)**: Error getting volume/partition 0. //! - **5 short blink (in a loop)**: Error opening root directory. //! - **6 short blink (in a loop)**: Could not open file 'O.TST'. //! //! See the `Cargo.toml` file for Copyright and licence details. #![no_std] #![no_main] // The macro for our start-up function use cortex_m_rt::entry; // info!() and error!() macros for printing information to the debug output use defmt::*; use defmt_rtt as _; // Ensure we halt the program on panic (if we don't mention this crate it won't // be linked) use panic_halt as _; // Pull in any important traits use rp_pico::hal::prelude::*; // Embed the `Hz` function/trait: use embedded_time::rate::*; // A shorter alias for the Peripheral Access Crate, which provides low-level // register access use rp_pico::hal::pac; // Import the SPI abstraction: use rp_pico::hal::spi; // Import the GPIO abstraction: use rp_pico::hal::gpio; // A shorter alias for the Hardware Abstraction Layer, which provides // higher-level drivers. use rp_pico::hal; // Link in the embedded_sdmmc crate. // The `SdMmcSpi` is used for block level access to the card. // And the `Controller` gives access to the FAT filesystem functions. use embedded_sdmmc::{Controller, SdMmcSpi, TimeSource, Timestamp, VolumeIdx}; // Get the file open mode enum: use embedded_sdmmc::filesystem::Mode; /// A dummy timesource, which is mostly important for creating files. #[derive(Default)] pub struct DummyTimesource(); impl TimeSource for DummyTimesource { // In theory you could use the RTC of the rp2040 here, if you had // any external time synchronizing device. fn get_timestamp(&self) -> Timestamp { Timestamp { year_since_1970: 0, zero_indexed_month: 0, zero_indexed_day: 0, hours: 0, minutes: 0, seconds: 0, } } } // Setup some blinking codes: const BLINK_OK_LONG: [u8; 1] = [8u8]; const BLINK_OK_SHORT_LONG: [u8; 4] = [1u8, 0u8, 6u8, 0u8]; const BLINK_OK_SHORT_SHORT_LONG: [u8; 6] = [1u8, 0u8, 1u8, 0u8, 6u8, 0u8]; const BLINK_ERR_2_SHORT: [u8; 4] = [1u8, 0u8, 1u8, 0u8]; const BLINK_ERR_3_SHORT: [u8; 6] = [1u8, 0u8, 1u8, 0u8, 1u8, 0u8]; const BLINK_ERR_4_SHORT: [u8; 8] = [1u8, 0u8, 1u8, 0u8, 1u8, 0u8, 1u8, 0u8]; const BLINK_ERR_5_SHORT: [u8; 10] = [1u8, 0u8, 1u8, 0u8, 1u8, 0u8, 1u8, 0u8, 1u8, 0u8]; const BLINK_ERR_6_SHORT: [u8; 12] = [1u8, 0u8, 1u8, 0u8, 1u8, 0u8, 1u8, 0u8, 1u8, 0u8, 1u8, 0u8]; fn blink_signals( pin: &mut dyn embedded_hal::digital::v2::OutputPin, delay: &mut cortex_m::delay::Delay, sig: &[u8], ) { for bit in sig { if *bit != 0 { pin.set_high().unwrap(); } else { pin.set_low().unwrap(); } let length = if *bit > 0 { *bit } else { 1 }; for _ in 0..length { delay.delay_ms(100); } } pin.set_low().unwrap(); delay.delay_ms(500); } fn blink_signals_loop( pin: &mut dyn embedded_hal::digital::v2::OutputPin, delay: &mut cortex_m::delay::Delay, sig: &[u8], ) -> ! { loop { blink_signals(pin, delay, sig); delay.delay_ms(1000); } } #[entry] fn main() -> ! { info!("Program start"); // Grab our singleton objects let mut pac = pac::Peripherals::take().unwrap(); let core = pac::CorePeripherals::take().unwrap(); // Set up the watchdog driver - needed by the clock setup code let mut watchdog = hal::Watchdog::new(pac.WATCHDOG); // Configure the clocks // // The default is to generate a 125 MHz system clock let clocks = hal::clocks::init_clocks_and_plls( rp_pico::XOSC_CRYSTAL_FREQ, pac.XOSC, pac.CLOCKS, pac.PLL_SYS, pac.PLL_USB, &mut pac.RESETS, &mut watchdog, ) .ok() .unwrap(); // The single-cycle I/O block controls our GPIO pins let sio = hal::Sio::new(pac.SIO); // Set the pins up according to their function on this particular board let pins = rp_pico::Pins::new( pac.IO_BANK0, pac.PADS_BANK0, sio.gpio_bank0, &mut pac.RESETS, ); // Set the LED to be an output let mut led_pin = pins.led.into_push_pull_output(); // Setup a delay for the LED blink signals: let mut delay = cortex_m::delay::Delay::new(core.SYST, clocks.system_clock.freq().integer()); // These are implicitly used by the spi driver if they are in the correct mode let _spi_sclk = pins.gpio2.into_mode::(); let _spi_mosi = pins.gpio3.into_mode::(); let _spi_miso = pins.gpio4.into_mode::(); let spi_cs = pins.gpio5.into_push_pull_output(); // Create an SPI driver instance for the SPI0 device let spi = spi::Spi::<_, _, 8>::new(pac.SPI0); // Exchange the uninitialised SPI driver for an initialised one let spi = spi.init( &mut pac.RESETS, clocks.peripheral_clock.freq(), 16_000_000u32.Hz(), &embedded_hal::spi::MODE_0, ); info!("Aquire SPI SD/MMC BlockDevice..."); let mut sdspi = SdMmcSpi::new(spi, spi_cs); blink_signals(&mut led_pin, &mut delay, &BLINK_OK_LONG); // Next we need to aquire the block device and initialize the // communication with the SD card. let block = match sdspi.acquire() { Ok(block) => block, Err(e) => { error!("Error retrieving card size: {}", defmt::Debug2Format(&e)); blink_signals_loop(&mut led_pin, &mut delay, &BLINK_ERR_2_SHORT); } }; blink_signals(&mut led_pin, &mut delay, &BLINK_OK_LONG); info!("Init SD card controller..."); let mut cont = Controller::new(block, DummyTimesource::default()); blink_signals(&mut led_pin, &mut delay, &BLINK_OK_LONG); info!("OK!\nCard size..."); match cont.device().card_size_bytes() { Ok(size) => info!("card size is {} bytes", size), Err(e) => { error!("Error retrieving card size: {}", defmt::Debug2Format(&e)); blink_signals_loop(&mut led_pin, &mut delay, &BLINK_ERR_3_SHORT); } } blink_signals(&mut led_pin, &mut delay, &BLINK_OK_LONG); info!("Getting Volume 0..."); let mut volume = match cont.get_volume(VolumeIdx(0)) { Ok(v) => v, Err(e) => { error!("Error getting volume 0: {}", defmt::Debug2Format(&e)); blink_signals_loop(&mut led_pin, &mut delay, &BLINK_ERR_4_SHORT); } }; blink_signals(&mut led_pin, &mut delay, &BLINK_OK_LONG); // After we have the volume (partition) of the drive we got to open the // root directory: let dir = match cont.open_root_dir(&volume) { Ok(dir) => dir, Err(e) => { error!("Error opening root dir: {}", defmt::Debug2Format(&e)); blink_signals_loop(&mut led_pin, &mut delay, &BLINK_ERR_5_SHORT); } }; info!("Root directory opened!"); blink_signals(&mut led_pin, &mut delay, &BLINK_OK_LONG); // This shows how to iterate through the directory and how // to get the file names (and print them in hope they are UTF-8 compatible): cont.iterate_dir(&volume, &dir, |ent| { info!( "/{}.{}", core::str::from_utf8(ent.name.base_name()).unwrap(), core::str::from_utf8(ent.name.extension()).unwrap() ); }) .unwrap(); blink_signals(&mut led_pin, &mut delay, &BLINK_OK_LONG); let mut successful_read = false; // Next we going to read a file from the SD card: if let Ok(mut file) = cont.open_file_in_dir(&mut volume, &dir, "O.TST", Mode::ReadOnly) { let mut buf = [0u8; 32]; let read_count = cont.read(&volume, &mut file, &mut buf).unwrap(); cont.close_file(&volume, file).unwrap(); if read_count >= 2 { info!("READ {} bytes: {}", read_count, buf); // If we read what we wrote before the last reset, // we set a flag so that the success blinking at the end // changes it's pattern. if buf[0] == 0x42 && buf[1] == 0x1E { successful_read = true; } } } blink_signals(&mut led_pin, &mut delay, &BLINK_OK_LONG); match cont.open_file_in_dir(&mut volume, &dir, "O.TST", Mode::ReadWriteCreateOrTruncate) { Ok(mut file) => { cont.write(&mut volume, &mut file, b"\x42\x1E").unwrap(); cont.close_file(&volume, file).unwrap(); } Err(e) => { error!("Error opening file 'O.TST': {}", defmt::Debug2Format(&e)); blink_signals_loop(&mut led_pin, &mut delay, &BLINK_ERR_6_SHORT); } } cont.free(); blink_signals(&mut led_pin, &mut delay, &BLINK_OK_LONG); if successful_read { info!("Successfully read previously written file 'O.TST'"); } else { info!("Could not read file, which is ok for the first run."); info!("Reboot the pico!"); } loop { if successful_read { blink_signals(&mut led_pin, &mut delay, &BLINK_OK_SHORT_SHORT_LONG); } else { blink_signals(&mut led_pin, &mut delay, &BLINK_OK_SHORT_LONG); } delay.delay_ms(1000); } }