> For the complete documentation index, see [llms.txt](https://development-test.pycom.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://development-test.pycom.io/firmware-and-api-reference/pycom/machine/sd.md).

# SD

The SD card class allows to configure and enable the memory card module of your Pycom module and automatically mount it as `/sd` as part of the file system. There is a single pin combination that can be used for the SD card, and the current implementation only works in 1-bit mode. The pin connections are as follows:

`P8: DAT0`, `P23: SCLK` and `P4: CMD` (no external pull-up resistors are needed)

If you have one of the Pycom expansion boards, then simply insert the card into the micro SD socket and run your script.

{% hint style="info" %}
Make sure your SD card is formatted either as FAT16 or FAT32.
{% endhint %}

## Quick Example Usage:

```python
from machine import SD
import os

sd = SD()
os.mount(sd, '/sd')

# check the content
os.listdir('/sd')

# try some standard file operations
f = open('/sd/test.txt', 'w')
f.write('Testing SD card write operations')
f.close()
f = open('/sd/test.txt', 'r')
f.readall()
f.close()
```

## Constructors

#### class machine.SD(id, ...)

Create a SD card object. See [`sd.init()`](/firmware-and-api-reference/pycom/machine/sd.md#sd-init-id-0) for parameters if initialisation.

## Methods

#### sd.init(id=0)

Enable the SD card.

#### sd.deinit()

Disable the SD card.

{% hint style="info" %}
Please note that the SD card library currently supports FAT16/32 formatted SD cards up to 32 GB. Future firmware updates will increase compatibility with additional formats and sizes.
{% endhint %}