We are pleased that our bearing design for Microchip’s Knob on Display™ or KoD™ family of controls has generated so many questions!

Below are some ‘Frequently Asked Questions’ to help clarify some of the functions and features of the BNL KoD™ for Microchip. 




What is a  Knob on Display™ or KoD™?

  • A Knob on Display™ or KoD™, is a capacitive rotational control that connects to the surface of a touchscreen, eliminating any cutting or invasive operations to the screen surface. Developed with and for Microchip, the BNL KoD™ uses our control knob bearing technology and is customizable to individual client requirements from an initial reference design.

How does it adhere to the screen?

  • The BNL KoD™ bearing uses full pad adhesion that can withstand 40kgs of force. The adhesive offers waterproofing and dustproofing in line with automotive specifications and industry standard testing.

Microchip maXTouch® Knob on Display (KoD™) Touch Controller

How does it connect to the screen?

  • BNL’s KoD™ bearings have an electrical path from the touch ring to the surface of the screen. The screen reads a change in capacitance through detecting contact from the electrode pad through the compression spring that contacts the chrome coating of the touch ring. As the touch ring is touched, the screen detects the touch, then tracks the rotational movement to the electrode pad.

Is the connection consistent?

  • The BNL version of the KoD™ has full and consistent contact with the screen. They are designed to rotate smoothly for constant electrode contact so the signal remains consistent.

Will the KoD™ work if the user is wearing gloves?

  • Yes, the BNL KoD™ can be used with gloves. The conductive cap uses the highest performance polymer bearing surfaces, conductive materials, coatings and plating, allowing the screen to track its rotation and position. It is sensitive to still pick up touch signals through most glove materials.

Does the BNL KoD™ have a push function?

  • The BNL KoD™ has both a rotational function and a push function, or ‘rise & fall’ – but we can ‘turn off’ the push function if a customer only requires the KoD™ to rotate. We can design the BNL KoD™ with different directional functions dependent on available space – north, south, east, west, push, pull, clockwise and counter-clockwise.

Can we customize the design?

  • Yes, the BNL KoD™ is meant to be customised to your requirements using the Microchip reference design as a starting point and meeting automotive industry standards.
  • BNL can design the bearing for use with customer specific sensors and materials, with an open or closed centre, in different sizes, with a push function or rotation only and different decorative surface finishes.

We would like a specific sound and feel. Can the haptics be customized?

  • Haptics can be designed to your specification. We do not have fixed number of haptic detents and we use a tuneable haptic spring. These BNL design features allow us to customize the haptic feedback to your needs.

Is the bearing sealed?

  • The KoD reference design is sealed with a silicone o-ring and labyrinth – most automotive customers demand this, as we must pass water/dust ingress tests.

Where can I get a BNL KoD™?

  • Contact us. Reference KoD™ parts are available and validated against the Microchip screen. BNL offer production customization in partnership with Microchip and we will work with individual companies’ validation tools to access connectivity to screens. We offer entry level options and full solutions for on-screen capacitive controls. We also design mechanical control knob bearings for automotive applications, domestic appliances and heating controls.