1. The limiting factor is parasitic capacitance, Cp. The smartsense algorithm that powers the MBR3 device has a limitation of 45 pF. It is observed that with buttons larger than 15x15 mm, the parasitic capacitance, Cp is higher than 45pF and the device may fail to register a touch.
2. No. This is not possible in MBR3 device.
3. Trackpad/Touchpad is not supported in MBR3. The only supported widgets are buttons, sliders and proximity sensors.
Thanks and regards
Thank you for prompt reply.
let me explain you in more detail.
1) Product A
It is a button cell powered bluetooth low energy user interface with a area 42mm x 42mm assigned for touch buttons.
We wish to place four touch buttons as per attached sketch. We will manage in the software this four touch buttons in such a way that either the entire area ( touch button 1, touch button 2, touch button 3, touch button 4 ) as one button or four individual buttons or two buttons ( touch button 1+touch button2, touch button3+touch button 4). Since we are keeping the button sizes and ground clearance s within the specifications given. We strongly feel that with above arrangement as four small buttons, two medium button or one big button will work. Please comment.
2) Product B
This is also button cell powered bluetooth low energy device. Can we use the button size other than 15x15mm ( 225 sqmm ) keeping the area within 225 sqmm. e.g. 20mm x 10mm.
If the answer to 1 and 2 is NO then please suggest suitable device which can operate on button cell and it is a low cost.
Gladiance Automation Pvt. Ltd. Kolhapur
BTLE_product_key_details.pdf 384.9 K
1. Product A-
MBR3 cannot be programmed for such an operation. It can only be configured to detect the button press using the smart sense algorithm. Please consider using the PSoC devices which allow programming the chip for additional operations. It also allows manual tuning for better sensitivity when parasitic capacitance is higher.
You can use the PSoC 4000 device which have pin compatibility with MBR3 devices (in case the layout is already designed). The PSoC 4000S, 4100S and 4100S plus have the latest CapSense IP for better performance and advanced features.
2. Product B-
Yes. This understanding is correct. The area is the factor contributing to the parasitic capacitance.
Thanks and regards