Support for Microchip Touch Controls

Extending its support for the use of touch controls in designs, Altium Designer provides support for creating planar capacitive sensor patterns on your PCB, for use with the range of Microchip® mTouch® sensor controllers.

Supported Sensors

The following sensor types are available for use in your PCB designs:

• Chevron Slider
• Linear Slider
• Mutual Ring Sensor

Each of these sensors are self-capacitance, one-dimensional sensors – they detect movement of your finger along a single axis.

Sensor Implementation

A touch sensor is implemented in a design by placing and configuring the required sensor type from the dedicated Microchip mTouch integrated library (Microchip mTouch.IntLib), located in the \Library\mTouch folder of the installation.

When configured as required, simply update the target PCB – an ECO is used to effect the required changes, resulting in the creation of the sensor pattern for placement on the PCB. Each sensor component on the PCB isn't a footprint in the normal sense, but rather the actual copper electrode pattern. An overlaying panel would be placed over a sensor when the board is assembled.

Implementing a touch control is a snap - just place the required sensor type component on the schematic, configure it as applicable to your design needs, then push the changes over to the PCB to obtain the sensor pattern.

The following sections take a closer look at the configurable sensor components available for placement in a design, their configuration options, and the resulting sensor pattern obtained on the PCB side. In each case, the default configurations are presented.

Chevron mTouch Slider

Use the mTouchChevronSlider component to implement an n-channel chevron slider, for connection directly to a Microchip mTouch sensor controller. The resulting sensor pattern on the PCB is comprised of a 1xn array of chevron-shaped electrodes, where n is the number of devices specified. In essence, you are specifying n separate sensors placed physically adjacent to each other. You have global control over the height and width of the constituent sensors, as well as control over the chevron angle. You can also control the gap between neighboring sensors.

Default configuration and resulting sensor pattern for the Chevron mTouch Slider.

Linear mTouch Slider

Use the mTouchLinearSlider component to implement a simple 2-channel linear slider, for connection directly to a Microchip mTouch sensor controller. The resulting sensor pattern on the PCB is comprised of two electrodes. In essence, these are two separate sensors placed physically adjacent to each other. Electrode shape is formed by a defined square and triangle. The electrodes are arrange such that their triangular parts almost interlock, separated by a defined gap. This design of slider gives the most linear output as a user's finger passes from one sensor across to the other.

Default configuration and resulting sensor pattern for the Linear mTouch Slider.

Mutual Ring mTouch Sensor

Use the mTouchMutualRingSensor component to implement a simple 2-channel mutual ring sensor, for connection directly to a Microchip mTouch sensor controller. The resulting sensor pattern on the PCB is comprised of two electrodes, in concentric fashion, with a definable gap between the two. Simply define the radius for the inner pad, and a 'thickness' for the outer pad.

Default configuration and resulting sensor pattern for the Mutual Ring mTouch Sensor.

Microchip Sensor Controllers

Microchip mTouch sensor controllers (typically PIC devices) – to which the corresponding electrodes from the sensor patterns connect – can be found on the Microchip pages, within the Unified Components section of the Content Store. Browse components directly in the store or through the browser-based interface to the Altium Vault in which the components reside. Connect to the Altium Vault through Altium Designer and place components into your designs. Alternatively, download the required integrated library,as a Zip file, from the applicable store page.