SD (secure digital) cards (sometimes called flash cards) have become the industry standard for portable memory in cell phones, laptops, digital cameras and other devices. But SD cards can do more than store and recall data. Secure digitial input/output (SDIO) cards can actually expand the functionality of your device. SDIO cards haven’t been widely adapted yet, but as electronic devices become more portable and this standard takes hold, we may see SD cards transforming our computers and smartphones in a big way.

How Does SDIO Work?

For the end user, an SDIO card is incredibly simple. All you do is insert the SDIO card into your normal memory card slot and you’re ready to go. The SDIO card includes all the firmware and software needed to operate the peripheral that’s integrated into the SDIO card. For example, an SDIO card may have a small camera attached or WiFi receiver built-in. To use the SDIO peripheral with a smartphone or laptop, all you would have to do is insert it into the slot—no installation or drivers required.

What Types of SDIO Cards Are Available?

One of the first SDIO cards were developed for PDAs, such as the Palm Treo. These allowed Palm users to add Wi-Fi, Bluetooth, GPS, digital cameras, TV tuners, FM radio tuners, RFID readers and other features to their phones without upgrading the hardware in their phone. Another widespread SDIO card is the Eye-Fi SD card, which works as a wireless Internet radio for digital cameras. Several photo sharing and printing companies have partnered with Wi-Fi to have the SD card automatically upload your photos to their online photo service.

How Can I Tell If My Device Supports SDIO?

Not all devices support SDIO cards. Most times, the SDIO card will tell you which devices it is intended for and which devices it is compatible with. But because SDIO is a standard maintained by the SD Association, if a device is listed as SDIO compatible, it means that it is compatible with all current SDIO devices.

What is the Future of SDIO?

When SDIO was first released, the technology received much fanfare and hype. However, recent smartphones haven’t taken advantage of SDIO. This is mostly because most cell phones now incorporate all the hardware add-ons that SDIO offered, such as GPS, cameras and WiFi. But there is also likely some hesitance for cell phone manufacturers and carriers to allow users to expand the functionality if their devices using third-party I/O cards. Part of the business model of cell phone developers is to limit the full technological potential of their phones in order to steer users to paid proprietary apps and hardware. SDIO support may make this more difficult.
But newer mobile platforms, such as Android, embraces a more open approach to mobile computing, which means that SDIO may see a resurgence in the future. Furthermore, the rise of netbooks and tablets may be a good fit for SDIO cards, since these devices are typically difficult or impossible to upgrade.