I have an old tried-and-true saw: give me 10 engineers, and I can build 1 of anything. The trick is building thousands, and that takes a little more planning and less improvisation. With that in mind, Cypress has a new capacitive touch interface solution.

Today’s CapSense Express announcement is about more than just tuning, and I’ll let you read the details. I want to focus briefly on Cypress’ claim of being the only auto-tuning solution available now for capacitive touch interface.

Talking with Ken Johnston, Sr. Marketing Manager for CapSense, gave me some insight into the exact problem. Tuning an interface isn’t news in the mixed signal world; it’s a required part of the manufacturing process. Ken described the solution fairly simply (it’s not that simple) as automatically tuning for variations in parasitic capacitance and calibrating the touch interface, but the sources of the problem were interesting.

• PCB layout is one source. Ken said that Cypress has a reference design layout to aid designers using the CY8CMBR2044 that provides a baseline, but variations from PCB to PCB need to be tuned out.
• Overlay capacitance also varies, and needs to be tuned out.
• Capacitance can also vary with environmental conditions.
• Now try to manufacture the same device in several different locations with the same level of quality worldwide, and autotuning becomes a real plus.
• Finally, there are some rather exotic variations, like paint or some other coating being applied over the interface, which Ken says won him a customer when this solution tuned that effect out.

Quoting the press release: “With SmartSense auto-tuning, the device dynamically optimizes the baseline and detection threshold and adjusts for the optimal capacitance sensing range at power up and during runtime as environmental conditions change.” While you and your 10 engineers could certainly develop this type of IP and process, Cypress is betting they’ve developed a robust solution that will get you to market faster compared to non-auto-tuned capacitive touch solutions.

This opens up touch interface design from being one of the black arts to being something that developers can implement quicker, more easily, and with low risk. There’s a Design Toolbox which helps with the layout, no programming tools or firmware to deal with, and no tuning required. Seems like a good plan.