What is SD?
SD describes devices that conform to SD standards for non-volatile memory cards. See the SD Association website for details.
Are there size limitations for the cards that can be inserted into the SD slot?
Yes. The SD card specification for a memory card is 32mm by 24mm by 2.1mm. You can also use thinner cards, such as MultiMediaCards (MMC). Avoid using cards that have a thickness greater than 2.1mm, as they might damage the SD card slot if you try to insert them.
Which SD card formats work in the SD card slot?
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Cards that conform to the SD 1.x, 2.x, and 3.x standards should work. The SD card slot can use:
- Standard SD, 4MB to 2GB
- SDHC (Secure Digital High Capacity), 4GB to 32GB
- SDXC, 4GB to 2TB
- MMC (MultiMediaCards)
- UHS‑II, up to 2TB (iMac Pro only)
You can use a passive adapter like the one shown here to make MiniSD, MicroSD, and higher density formats like MiniSDHC and MicroSDHC conform to the width and thickness specifications listed above:
How fast can my Mac read or write to an SD card in the SD card slot?
Mac notebooks use the USB bus to communicate with the SD card slot. They have a maximum speed of up to 480Mbit/s. Mac desktops use the PCIe bus to communicate with the SD card slot. Desktops can transfer data at a faster rate.
Check the packaging that came with your SD media to determine the maximum transfer rate that your specific card uses.
To determine the maximum transfer speed of your Mac, you can use System Information. Choose Apple () menu > About This Mac and then click System Report.
If you use a Mac notebook:
- Select Hardware, then select USB.
- Select Internal Memory Card Reader and look for the Speed entry.
If you use a Mac desktop computer:
- Select Hardware, then select Card Reader.
- Look for the Link Speed entry. Computers that use the PCIe bus express their speed as GT/s.
Does the SD slot work with cards that exceed 32GB?
Yes. However, most media manufacturers preformat the media using common block-and-cluster sizes that don’t approach the theoretical limits of a given file system.
Most SD cards use the FAT32 file format, and preformatted FAT32 SD media is commonly available up to a capacity of 32GB. Media that exceeds 32GB usually uses the exFAT file system, while some smaller capacity cards use the FAT16 file format. Preformatted FAT16 media is generally available up to a capacity of 2GB.
Minidisc Reader For Pc
If you use OS X Snow Leopard 10.6.5 or later, you can find out which file system you’re using:
- Insert the media into the SD card slot.
- Choose Apple menu > About This Mac.
- Click System Report.
- In the Hardware section, click Card Reader, and find the File System field.
Will the SD card slot work with SD cards that use the exFAT file system?
Yes. Any Mac that has an SD card slot and is running OS X 10.6.5 or later can use the exFAT file system.
exFAT is also supported in Boot Camp with Windows 7, 8.1, or 10 on any Mac made in 2011 or later with an SD card slot.
How do I insert media into the SD card slot?
When you insert the card, make sure that the metal contacts face down and point toward the computer. Don’t force media into the SD card slot, as this might cause damage.
How does my Mac use the media inserted into the SD card slot?
Your computer recognizes a card inserted into the SD card slot as a USB storage device. You can mount, read from, and write to the SD card just like you can with any other USB storage device.
I put the card in the slot, but it didn’t mount. What should I do?
Remove the card and insert it again. Sometimes the SD card won’t mount properly if you put it into the slot too slowly.
When I try to write content to the card, I get a 'cannot be modified' message. How can I fix this?
You see this message when you try to edit data on an SD card that’s locked. You need to use the lock slider to unlock the card before you can edit the data.
To eject the card, drag the icon that represents the card to the Trash. After the icon disappears from the desktop, you can remove the card from the computer. Adjust the lock slider tab to unlock the card, then reinsert the card into the slot. See the manufacturer’s instructions for the location of the slider tab.
Can I use Disk Utility to reformat an SD card?
You can use Disk Utility to partition and format an SD device as FAT32 (using the MS-DOS FAT setting) or Mac OS Extended. The Mac OS Extended format can be used only on Macintosh systems. Non-Apple systems won’t recognize cards formatted to Mac OS Extended.
You might have to format a card that’s larger than 32GB with exFAT if you want to use it with a digital camera, GPS, or another device. When in doubt, format the card in the device that you intend to use it with.
Can I install macOS on an SD storage device and use it as a startup volume?
Use Disk Utility to change the default partition table to GUID. Then format the card to use the Mac OS Extended file format.
How do I remove a card from the SD card slot?
Before you remove the card, allow any data transfer to SD media to complete. To eject the card, drag the icon that represents the card to the Trash. After the icon disappears from your desktop, you can remove the card from the slot.
Don't remove a card while your Mac is sleeping, as this could lead to data loss. Always wake your computer and eject the SD card before removing it from your Mac.
Can I use Secure Digital Input Output (SDIO) cards?
Can I use macOS to see the specifications for the interface hardware and media inserted in the SD card slot?
You can get information about the interface hardware and the media that you inserted in the slot from the System Information:
- Choose Apple menu > About This Mac.
- Click System Report.
- In the Hardware section of System Information, select USB.
- In the list of USB devices, select Internal Memory Card Reader to access information about the interface hardware and the media inserted into the SD card slot.
Can I use the SD card slot while running Windows using Boot Camp?
The SD card slot works with Boot Camp in all supported versions of Windows. You’ll need to download and install the Windows Support Software to use the SD card slot with Windows.
Learn more about using Windows on a Mac.
Can I use an SDXC card on my Mac with Windows?
You can use an SDXC card in Windows 7, Windows 8, and Windows 10 with these Mac computers:
- MacBook Pro (Early 2011 and later)
MacBook Pro models from 2016 and later don't have a built-in SD card slot. You can use a USB-C card reader, or a combination of a USB-C to USB Adapter and a USB card reader. - MacBook Air (Mid 2011 and later)
- Mac mini (Mid 2011 and later)
Mac mini (Mid 2010) doesn't support SDXC cards. - iMac (Mid 2011 and later)
iMac (Mid 2010) doesn't support SDXC cards.
Can I use an SD, SDHC, or SDXC card to install Windows on my Mac?
No. You can’t use SD, SDHC, or SDXC cards with Boot Camp to install Windows software on Mac computers.
Fortunately, a very large number of developers have created software for use with our OBD integrated circuits. We list just a sampling of what is available here, to get you started. They are grouped based on the operating system:
- Windows
- Mac OS X
- Linux
- iOS
- Android
- Other Software
- Remote Connections
Windows Software
The following are just a few of the programs that are available for the Windows platform:
AutoScan OBD2
Sapphirefoxx bilibili stars bars and stripes. Autosafe Diagnostics offers the AutoScan OBD2 software for the PC. You can download a free trial before you buy.
Minidisc Reader For Mac Windows 10
Com Port Terminal
This is a bare bones (but free) terminal program from WGSoft. Works well for communicating with the ELM327.
EngineCheck
Gendan’s EngineCheck for ELM-based tools.
FORScan
As the web site says, FORScan is a software scanner for Ford, Mazda, Lincoln and Mercury vehicles, designed to work over ELM327 and compatible OBD2 to RS232 interpreters.
freediag
A SourceForge project that provides a command line interface for controlling OBDII interfaces (with some support for ELM327 devices). Versions available for Windows, and Linux too.
iMechatronics.com
…keeps a list of (mostly) Windows software that you might find convenient.
LapLogger
LapLogger.com offers software and interface packages for a variety of platforms.
OBD 2007
GLM Software offers a Lite (free) version OBD 2007 program, in addition to the full one.
OBD Auto Doctor
OBD Auto Doctor is available for Windows, Mac and Linux.
OBD2Spy
Offers software for Elm and mOByDic based interfaces.
OBD Logger
A basic software package for reading trouble codes, and real-time data. Available for Windows and Unix/Linux.
openOBD
A SourceForge project that provides a GUI for controlling ELM327 devices. Versions available for Windows and Linux.
PC Scan Tool
Some assorted bits of OBD info, and a link to a freeware PC scan tool. It is no longer supported, but is still useful.
PCMSCAN
This software is full-featured and works with a large number of interfaces.
RealTerm
Is another great free terminal application, that is certainly worth a try.
Scanclic
Most of the OBD software available is in English, but if you prefer Italian, one company (Informaticlaclic) offers Windows and Android software packages that may be of interest to you.
ScanMaster-ELM
WGSoft has been offering the full-featured ScanMaster software for a number of years. They offer great support, and a very reasonable price, considering all the features.
ScanTool.net open source software
ScanTool.net started an open-source project several years ago. It is still available on the SourceForge site:
http://sourceforge.net/projects/scantool/
ScanXL Pro
In addition to the PCMSCAN software, Palmer Performance also offers ScanXL. If you purchase the vehicle-specific versions, ScanXL will provide access to a great deal more than just the standard OBD information.
SynchroScan
The eurOBDiag group in France brings us this software.
Tera Term Pro
By T. Teranishi, this is yet another free terminal program. It hasn’t been updated for some time, but should still work well on many systems. If you are interested in this program, be sure to also look at the Tera Term project at SourceForge.
Terminal 1.9b
Bray++ has offered several versions of this program since 1997. It’s a good way of directly ‘talking’ to your ELM327 circuit (and the vehicle), made even easier with the macro and scripting capability. It’s donation-ware, so don’t forget to send him something if you use it.
Termite
This is a bare bones (but free) terminal program from CompuPhase. It has a nice, simple interface, and offers a large number of features.
TouchScan
OCTech offers this complete Windows based (Vista SP2 or later) system for obtaining and displaying vehicle info. If you wish to go into more detail, they also have a reasonably priced add-on package.
WinALDL
A 160 baud ALDL reader (that’s pre OBDII) for those vehicles that use it. The software is 32 bit Windows only.
Macintosh OS X Software
There aren’t as many titles available for the Macintosh, but these will get you started:
EOBD-Facile
The people that brought us the iOS version of EOBD-Facile now offer a Mac OSX version. The free download allows you to read trouble codes, while the paid version offers full functionality. See the Outils OBD Facile YouTube page for additional info.
goSerial
Andreas Mayer offers a great little program for directly ‘talking’ to your ELM327 circuit. It’s donation-ware, so if you like it, consider sending something his way.
Movi and Movi Pro
Only for the Mac, there are two versions of this software. The standard version provides all the basic OBD functions, while Movi Pro adds more bells and whistles. If you just want to try it out, the download will operate in demo mode.
OBD Auto Doctor
OBD Auto Doctor is available for Windows, Mac and Linux.
OBD GPS Logger
Useful for logging both GPS and OBD data, if you should wish to compare vehicle data and location. Exports data in a few useful ways. Available for Mac OSX and Linux.
LapLogger
LapLogger.com offers software and interface packages for a variety of platforms.
ZTerm
Dave Alverson provides terminal software too. Even though the site does not say so, we have had no trouble using it with Mavericks.
Linux Software
Here are a few Linux apps:
CuteCom
Alexander Neundorf offers this graphical serial terminal program. Note that there are no precompiled versions at this link – you will have to make your own.
freediag
A SourceForge project that provides a command line interface for controlling OBDII interfaces (with some support for ELM327 devices). Versions available for Windows and Linux.
minicom
This link takes you to the nixCraft site for info on installing and setting up minicom. Very DOS-like, but it gets the job done.
OBD Auto Doctor
OBD Auto Doctor is available for Windows, Mac and Linux.
OBD GPS Logger
Useful for logging both GPS and OBD data, if you should wish to compare vehicle data and location. Exports data in a few useful ways. Available for Mac OSX and Linux.
OBD Logger
A basic software package for reading trouble codes, and real-time data. Available for Windows and Unix/Linux.
openOBD
A SourceForge project that provides a GUI for controlling ELM327 devices. Versions available for Windows and Linux.
Perl OBD-II Logger
Open source software for logging OBD-II PID data. The sampling periods/rates can be customized for each PID. Runs primarily on Linux, but also on Windows if you install a Perl interpreter. Includes SYSV init scripts for running on the Raspberry Pi in dedicated “headless” mode.
picocom
A very minimal terminal emulation program that runs on Linux.
pyOBD
Python-based interface for use with Elm devices, now maintained by SECONS Ltd.
Note that there are several versions of this program available, so check around if you are discouraged with this package (see pyOBD-II and roflson/pyobd).
pyOBD-II
As the description says, pyOBD-II (a.k.a. “pyobd2”) is a Python library for communicating with OBD-II vehicles. Its goal is to make writing programs for vehicle diagnostics and monitoring vehicle data as easy as possible. Relies on pySerial to communicate with ELM scanners.
roflson/pyobd
Python-based interface that offers several improvements over the original pyOBD.
ScanTool.net open source software
ScanTool.net started as an open-source project several years ago, for use with the Windows OS. Apparently it’s quite usable on the Linux platform too – install it from the Ubuntu Software Center, or if you wish, by following this excellent Sam Hobbs tutorial.
Serialclient
A simple bit of software for communicating with a serial port from the command line.
iOS Software
The iPhone, iPad , and iPod continue to be very popular ways of interfacing to the ELM327.
A word of caution – the Bluetooth that Apple uses in iOS devices does not currently support the Serial Port Protocol (SPP). As such, iOS devices can not connect to ELM327 modules with Bluetooth – you must use WiFi with your device*.
AutoProPlus
AutoProPlus is a free app for monitoring your vehicle with an iPhone. A little difficult to figure out as the Owner’s Manual and web site are both very minimal.
BT1
Another bit of software that works using Bluetooth, but only if you also purchase the GoPoint Technology BT1 interface module.
DashCommand
Palmer Performance are here with another app for ELM327s and compatibles. DashCommand is a reasonable price considering what you get. You can also purchase enhancements that allow more than just generic data for many vehicles.
Engine Link
This app continuously monitors several engine parameters, but it’s not clear how you can modify (or stop) them. It does allow you to define custom PIDs though, which might be handy (depending on just what you are using the scan tool for).
EOBD Facile
The basic version of this app is free, and works well. It provides some vehicle information, and will read trouble codes, but you can not clear them unless you buy the full package. Once you’ve got to that point, you will know how you like the software, and the decision should be easy. Well worth a try.
ezOBD
Up and Running have a free app that may be just what you’re looking for. The reviews aren’t in on it yet, but it is being updated regularly.
FORScan Lite
Lite version of the popular Windows software. Requires a WiFi ELM327 (or compatible) device.
iOBD2
This software offers free support for their iOBD2 hardware, but you must pay in order to connect to an ELM327 device.
NovaScan – The OBD Total Solution
ubiqCOM offers this software for the iPad or iPhone. Unfortunately, the free demo version will not connect to a vehicle, so you can not really try it before you buy it.
OBD Car Doctor
A great little bit of free software. Provides all the basics, and works quite well.
OBD Fusion
A full-featured interface from OCTech that sells for a reasonable price. Does just about everything that you would want and now even offers support for the Apple Watch.
* We are aware that older iOS devices have serial data available at the 30 pin connector, but do not know of any software that you could use to take advantage of it.
topAndroid Software
There’s a large number of Android Apps for talking to the ELM327. We’ve had to pare it down to a few of the most popular:
Car Gauge Pro
OBD Scantech’s app provides all the basics, as well as enhanced diagnostic data for many vehicles. The price is quite reasonable too.
CarSys Scan
OBD High Tech offers a free app that provides all the basics. For use with Bluetooth scan tools.
DashCommand
Palmer Performance also supports the ELM327 (and compatibles) on Android. This app only allows 30 minutes of (limited) use before you have to make your decision whether to buy.
eCar PRO
This software reads your OBD information through Bluetooth, but does more than just read trouble codes. You can see and compare sensor data, set alarms, display times, and calculate torque and horsepower.
EOBD Facile
The basic version of this app is free, and works well. It provides some vehicle information, and will read trouble codes, but you can not clear them unless you buy the full package. Once you’ve got to that point, you will know how you like the software, can decide whether to purchase the ‘Premium Access’ package. Well worth a try.
ELM327 Terminal
Designed to send pre-defined AT and OBD commands for you. It’s a free app that may be right for you.
Elm Basic
This is terminal program for sending commands to an ELM327 interface and receiving replies. Just what you may need if you want to stay in complete control.
FordSys Scan Free
Another app by OBD High Tech. This one caters to Ford vehicles, providing information from several vehicle modules as well as the OBDII diagnostics. For use with Bluetooth scan tools.
Honda Database
Need Honda trouble code or ECU info, or engine or transmission specs? If so, this handy app is certainly worth a look.
Kwik OBD Terminal
Another terminal program for sending commands to an ELM327 interface and receiving replies. Just what you may need if you want to stay in complete control.
Leaf Spy Pro
Owners of the Nissan Leaf will be interested in this Android app. There’s also a free version (Leaf Spy Lite) that will give battery info. The Leaf Spy Pro page on the Electric Vehicle Wiki is a must-visit too.
OBD Auto Doctor
This one is very similar to the iOS version, and it remains a free app too. A great little bit of software that provides all the basics and works well.
OBD Car Doctor
This one is very similar to the iOS version, and it remains a free app too. A great little bit of free software. Provides all the basics and works well.
OBD Trouble Codes Lite
Get trouble code descriptions on your phone or tablet. The free version of this app (ad sponsored) contains the generic trouble codes (from P0001 to P099F) in its database. The full (paid) version contains almost 20000 codes.
Piston (OBD2 & ELM327)
Marcin Gierlicki’s ‘Piston’ seems to be well designed, and worked well in testing. A free offering that should be one of the first to try.
RaceChrono
A popular lap timer app that logs both gps information and OBD data. The free version is time-limited, so if you find it useful, you will want to upgrade to the pro version.
ScanMaster for ELM327
A great free app from WGSoft.de, makers of the other ScanMaster programs. Should be one of the first apps that you try. Has in-app purchases.
Scanclic
Most of the OBD software available is in English, but if you prefer Italian, one company (Informaticlaclic) offers Windows and Android software packages that may be of interest to you.
ScanMyOpel Lite
This app is only for Opel/Vauxhall diagnostics, but that is exactly what many users are looking for. Try this Lite (limited) version before you decide whether to buy the full one.
Torque Lite
Free version of the popular app offers a lot for no cost.
Torque Pro
Is the full version of the app, which offers more features, supports more vehicles, and does not have ads.
TouchScan
This modestly priced app is getting fairly good reviews. If you’re looking for an app with a gauge type interface, this one is worth considering.
Note that most Android software requires that you already be paired with a Bluetooth device. We are often asked about pairing codes and while we can never know exactly what code would apply to your interface, we can say that most use either 0000 or 1234.
topOther Software
Some items that don’t fit into the above categories:
Electric Vehicle Wiki
Interest in electric vehicles continues to grow. If your interest is with them, you may find this Wiki helpful.
Engine Link
Use ELM327 Bluetooth adapters with your Windows Phone.
Nokia N800 and Carman
If anyone is still using a Nokia N800 internet tablet, they may wish to have a look at the Carman software. Looks like version 0.6.3 was the last one produced.
OBD Auto Doctor
OBD Auto Doctor is also available for the Windows Phone.
OBD Gauge
Dana Peters provides this software for the Palm or Pocket PC platforms. There’s even some Windows software for plotting the captured data.
opengauge
This is an open source project for interfacing the Arduino to OBD.
ptelnet
By Marcio Migueletto de Andrade is free and works well with Palm hand-held devices (if you are still using one). Besides basic communications, it allows macros to be defined, which is handy.
Raspberry Pi
If you’re experimenting with a Raspberry Pi board, then you are actually using a Linux system, so should refer to the section above for suggestions. There is one Pi-specific article that we’ve come across that you may find useful though. It’s called: Raspberry Pi Reading Car Diagnostics (OBD-II) Data.
Remote Connections
Occasionally we are asked about connecting to an ELM327 / OBD monitor from a remote location. There are a number of solutions for this. The following lists only a few:
HW VSP3 – Virtual Serial Port
This software adds a COM port to your computer that connects to a virtual serial port over a TCP/IP network (typically ethernet or WiFi). Windows only.
B&B Electronics’ VESP211 Serial Converters
A hardware/software solution for providing a serial port in a remote location. Requires a wired network connection to the module. Windows only.
Eltima Software’s FlexiHub
FlexiHub is another option for providing remote access to USB and COM devices over the internet or local network. It provides several options (including data encryption), but most appealing is the support for Windows, Mac, Linux and Android devices. See the FlexiHub Car diagnostic – remote car monitoring page for info on OBD monitoring.
FabulaTech’s Serial Port Redirector
An alternative for creating a virtual serial port over a TCP/IP network. It’s a little pricey for the experimenter, but it does provide a few features including SSL support. Windows only.
Tactical Software’s Serial/IP COM Port Redirector
Another alternative for creating a virtual serial port over a TCP/IP network. Windows only.