diff --git a/CMakeLists.txt b/CMakeLists.txt
index 586693c1..4bcae43d 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -4,6 +4,7 @@
 # CMakeLists in this exact order for cmake to work correctly
 cmake_minimum_required(VERSION 3.8)
 set(CMAKE_CXX_STANDARD 17)
+set(CMAKE_CXX_STANDARD_REQUIRED ON)
 
 include($ENV{ADF_PATH}/CMakeLists.txt)
 include($ENV{IDF_PATH}/tools/cmake/project.cmake)
diff --git a/main/CMakeLists.txt b/main/CMakeLists.txt
index d8e98ac6..085f5683 100644
--- a/main/CMakeLists.txt
+++ b/main/CMakeLists.txt
@@ -1,2 +1,2 @@
-idf_component_register(SRCS "gay-ipod-fw.cpp" "gpio-expander.cpp" "battery.cpp"
+idf_component_register(SRCS "gay-ipod-fw.cpp" "gpio-expander.cpp" "battery.cpp" "storage.cpp"
                     INCLUDE_DIRS ".")
diff --git a/main/gay-ipod-fw.cpp b/main/gay-ipod-fw.cpp
index 5f16ddc7..a01a99b1 100644
--- a/main/gay-ipod-fw.cpp
+++ b/main/gay-ipod-fw.cpp
@@ -1,17 +1,20 @@
 #include <stdio.h>
 
+#include "battery.h"
 #include "driver/adc.h"
 #include "driver/gpio.h"
 #include "driver/i2c.h"
+#include "driver/sdspi_host.h"
 #include "driver/spi_common.h"
 #include "driver/spi_master.h"
 #include "esp_adc_cal.h"
+#include "esp_intr_alloc.h"
 #include "esp_log.h"
 #include "gpio-expander.h"
-#include "battery.h"
 #include "hal/adc_types.h"
 #include "hal/gpio_types.h"
 #include "hal/spi_types.h"
+#include "storage.h"
 
 #define I2C_SDA_IO (GPIO_NUM_0)
 #define I2C_SCL_IO (GPIO_NUM_4)
@@ -69,24 +72,22 @@ esp_err_t init_spi(void) {
 
     // Use the DMA default size.
     .max_transfer_sz = 0,
-    // TODO: check flags
-    .flags = 0,
+    .flags = SPICOMMON_BUSFLAG_MASTER | SPICOMMON_BUSFLAG_IOMUX_PINS,
     .intr_flags = 0,
   };
 
   ESP_ERROR_CHECK(spi_bus_initialize(VSPI_HOST, &config, SPI_DMA_CH_AUTO));
 
-  // TODO: CS lines
-  // TODO: add devices to the bus (sd card and display)
-
   return ESP_OK;
 }
 
 extern "C" void app_main(void)
 {
   ESP_LOGI(TAG, "Initialising peripherals");
+
+  ESP_ERROR_CHECK(gpio_install_isr_service(ESP_INTR_FLAG_LOWMED));
   init_i2c();
-  //init_spi();
+  init_spi();
 
   ESP_LOGI(TAG, "Setting default GPIO state");
   gay_ipod::GpioExpander expander;
@@ -99,14 +100,18 @@ extern "C" void app_main(void)
   ESP_LOGI(TAG, "Init ADC");
   ESP_ERROR_CHECK(gay_ipod::init_adc());
 
+  ESP_LOGI(TAG, "Everything looks good! Waiting a mo for debugger.");
+  vTaskDelay(pdMS_TO_TICKS(2500));
+
+  ESP_LOGI(TAG, "Trying to init SD card");
+  gay_ipod::SdStorage storage(&expander);
 
-  while (1) {
-    uint32_t battery = gay_ipod::read_battery_voltage();
-    expander.Read();
+  ESP_ERROR_CHECK(storage.Acquire());
 
-    ESP_LOGI(TAG, "millivolts: %d, wall power? %d", battery, expander.charge_power_ok());
+  ESP_LOGI(TAG, "Looks okay? Trying to deinit now.");
+  vTaskDelay(pdMS_TO_TICKS(1000));
+  ESP_ERROR_CHECK(storage.Release());
 
-    vTaskDelay(pdMS_TO_TICKS(1000));
-    ESP_ERROR_CHECK(expander.Write());
-  }
+  ESP_LOGI(TAG, "Hooray!");
+  vTaskDelay(pdMS_TO_TICKS(1000));
 }
diff --git a/main/storage.cpp b/main/storage.cpp
new file mode 100644
index 00000000..b1d5aa6c
--- /dev/null
+++ b/main/storage.cpp
@@ -0,0 +1,72 @@
+#include "storage.h"
+
+#include "esp_check.h"
+#include "driver/sdspi_host.h"
+#include "esp_err.h"
+#include "gpio-expander.h"
+#include "hal/gpio_types.h"
+#include "hal/spi_types.h"
+#include "sdmmc_cmd.h"
+
+namespace gay_ipod {
+
+SdStorage::SdStorage(GpioExpander *gpio) {
+  this->gpio_ = gpio;
+}
+
+SdStorage::~SdStorage() {
+  ESP_ERROR_CHECK(sdspi_host_deinit());
+}
+
+esp_err_t SdStorage::Acquire(void) {
+  // First switch to this device, and pull CS.
+  gpio_->set_sd_mux(GpioExpander::ESP);
+  gpio_->set_sd_cs(false);
+  gpio_->Write();
+
+  // Now we can init the driver and set up the SD card into SPI mode.
+  sdspi_host_init();
+
+  sdspi_device_config_t config = {
+    .host_id = VSPI_HOST,
+    // CS handled manually bc it's on the GPIO expander
+    .gpio_cs = GPIO_NUM_2,
+    .gpio_cd = SDSPI_SLOT_NO_CD,
+    .gpio_wp = SDSPI_SLOT_NO_WP,
+    .gpio_int = GPIO_NUM_NC,
+  };
+  esp_err_t ret = sdspi_host_init_device(&config, &handle_);
+  if (ret != ESP_OK) {
+    gpio_->set_sd_cs(true);
+    gpio_->Write();
+    return ret;
+  }
+
+  host_ = sdmmc_host_t SDSPI_HOST_DEFAULT();
+  host_.slot = handle_;
+  // Will return ESP_ERR_INVALID_RESPONSE if there is no card
+  // TODO: use our own error code
+  ret = sdmmc_card_init(&host_, &card_);
+
+  // We're done chatting for now.
+  gpio_->set_sd_cs(true);
+  gpio_->Write();
+
+  return ret;
+}
+
+esp_err_t SdStorage::Release(void) {
+  gpio_->set_sd_cs(false);
+  gpio_->Write();
+
+  sdspi_host_remove_device(this->handle_);
+  sdspi_host_deinit();
+
+  gpio_->set_sd_mux(GpioExpander::USB);
+  gpio_->set_sd_cs(true);
+  gpio_->Write();
+
+  return ESP_OK;
+}
+
+} // namespace gay_ipod
diff --git a/main/storage.h b/main/storage.h
new file mode 100644
index 00000000..79267b0b
--- /dev/null
+++ b/main/storage.h
@@ -0,0 +1,34 @@
+#ifndef STORAGE_H
+#define STORAGE_H
+
+#include "driver/sdmmc_types.h"
+#include "driver/sdspi_host.h"
+#include "esp_err.h"
+#include "gpio-expander.h"
+
+namespace gay_ipod {
+
+class SdStorage {
+  public:
+    SdStorage(GpioExpander *gpio);
+    ~SdStorage();
+
+    esp_err_t Acquire(void);
+    esp_err_t Release(void);
+
+    // Not copyable or movable.
+    // TODO: maybe this could be movable?
+    SdStorage(const SdStorage&) = delete;
+    SdStorage& operator=(const SdStorage&) = delete;
+
+  private:
+    GpioExpander *gpio_;
+
+    sdspi_dev_handle_t handle_;
+    sdmmc_host_t host_;
+    sdmmc_card_t card_;
+};
+
+} // namespace gay_ipod
+
+#endif