---
title: "SD"
aliases:
    - firmwareapi/pycom/machine/sd.html
    - firmwareapi/pycom/machine/sd.md
    - chapter/firmwareapi/pycom/machine/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. 

> Make sure your SD card is formatted either as FAT16 or FAT32.


## 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.read()
f.close()
```

## Constructors

### class machine.SD([id])

Create a SD card object. See `sd.init()` for parameters.

## Methods

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

Enable the SD card. The id is always 0.

> Use the [os](/firmwareapi/micropython/uos/) module to manipulate files.

### sd.deinit()

Disable the SD card.

> 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.