An unresponsive controller can ruin a gamer's experience and get thrown across a room, but even a great controller has to stand up to a lot of abuse. C&K recently released a series of new tactile switches that give us a chance to think about what demands come with this application.
The Considerations of Game Controller Design
When designing a product, the environment it will be exposed to is a critical factor. High temperatures require high-temperatures parts, thermal cycling environments may need to consider expansion and solder cracking, etc.
A game controller is most often used in good conditions—a temperature-stable environment with controlled humidity. However, game controllers are not ordinary hardware. They have their keys smashed hundreds of times in a single minute, are pulled aggressively as a character navigates a scene, and are potentially launched across rooms when a gamer gets frustrated.
The Sony PlayStation DualShock controller, considered by some to be the pinnacle of good controller design. Image used courtesy of Evan Amos
Even though they're used in stable conditions, the violent movements and extensive handling that come with gaming create a harsh mechanical environment. The latest discussions may focus on advancements in gaming VR and upgrades to game graphics, but the manual interface is still key to the experience.
A decent game controller must use parts that are able to handle a high degree of mechanical force as well as plenty of mechanical cycles. A typical tactile switch may not do in such situations.
The Importance of a Good Switch
While some components in a circuit can be replaced with less expensive versions with little to no effect on the overall performance, there are some portions of a BOM that cannot afford sacrifice. Interfaces are a good example as the feeling of buttons and responsiveness of screens can be just as important as a device's specifications.
The latest discussions may focus on advancements in gaming VR and upgrades to game graphics, but the manual interface is still key to the experience. Reviews of poorly made products often focus on the feel of switch interfaces, describing them as being too heavy, to “plasticky," having “no tactile feeling at all,” or failing after several hard presses. Conversely, designers are continuing to update pushbutton switches to improve the user experience.
If you'd like to see an example of the insides of a gaming controller, check out our teardown of the Steam controller.
C&K Tactile Switches
To meet the demanding industry requirements on switches, C&K this week has announced their latest line of sin-miniature switches that are highly suitable for gaming environments. These switches, which can be directly mounted to PCBs, are customizable, allowing designers to fine-tune the exact feel and sound when pressed.
The KMT0 switch. Image used courtesy of C&K
One of their switch ranges is the KMT0 nano-miniature SMT top-actuated switches which have the smallest footprint in the C&K line. These switches are rated for up to 1 million cycles, have a contact current rating of 50mA, a contact resistance of less than 150mΩ, and operate between -40°C to 85°C. Its incredibly low profile and ability to handle many mechanical cycles make this switch also ideal for Bluetooth headsets and MP3 accessories.
The KXT3 switch. Image used courtesy of C&K
Another switch is the KXT3 ultra low profile top actuated tactile switch which measures just 3mm x 2mm and a height of 0.6mm. The switch is capable of performing up to 500,000 cycles with an operational temperature range of -40°C to 85°C. An alternative to the KXT3, the KSC2 and KSC4 are sealed tactile switches which are IP rated to IP67 making them incredibly resilient to the odd spill of energy drink, as well as being useful for outdoor equipment and even VR applications.
The KBD switch. Image used courtesy of C&K
Controllers are not the only products used by gamers. The computer keyboard is also one of the most common mechanical input devices for gaming. While anti-ghosting and LED backlights can be incredibly useful, the one feature that gamers (and even engineers) look for in a keyboard is tactile function; there is nothing like the feeling of an old IBM clicky keyboard! The KBD series of switches from C&K are tactile keyboard switches with an electrical life of up to 50 million presses. These switches are rated for 10mA at 12V, have a contact resistance of 200mΩ, and operate at temperatures between -10°C to 70°C.
Which other applications are these design considerations important for? What other tactile switches have you used in the past? Let us know in the comments below.