CapTIvate Development Kit
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The CapTIvate MCU Development Kit is a complete set to evaluate the MSP430FR2633 MCU and the capacitive touch.
It can be used as a stand-alone board or as a BoosterPack. |
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Hardware
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The box is impressive and contains:
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The main board features a MSP430FR2633 MCU and the phone capacitive phone board comes with a haptic feed-back.
The board can also be used as a BoosterPack. In that case, one needs to solder 20 pins and develop a library so the master can read and process the data from the MSP430FR2633 board. |
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Software
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The main software is the CapTIvate Design Center GUI, available for Windows, Linux and macOS.
Configuring a capacitive board is very easy thanks to the automatic options, one for assigning the I/O and another for generating the code. The code is then compiled on CCS and uploaded to the CapTIvate board. |
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Project
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The three capacitive boards provided with the development kit are rather specific. I wanted a more generic example I could use with different projects, like a board with 8 x 8 pads for a calculator.
I went through the three steps on the CapTIvate Design Center GUI. I asked for automatic assignation and then tuned the ports based on the schematics. The code generated for the sensor MCU compiled and ran on the first try on the board turned BoosterPack. The CapTIvate board rises an interrupt on pin 8 and sends the messages in bulk, through UART or I²C. There's another option for I²C, register mode, but it isn't implemented yet. I chose the I²C bulk protocol. There are five kinds of messages called packets: the Cycle, Sensor, TrackPad, and General Purpose Packets are unidirectional (from the board to the master) while the Parameter Packets are bidirectional. The only challenge was developing the library to decode the messages on the master MCU. The Technology Guide provided all the information needed. The critical chapter is the Communication Module, and describes how the messages are configured. All the messages use only one format, the Cycle Packet. This eases reading and decoding. A logic analyser was very helpful! On the final result, pads with proximity are in orange and pads with touch are in green. I put my left hand on the capacitive board: the board detected 8 pads with touch and 7 pads with proximity. Learn more about project at the page Multi-Touch Project with CapTIvate. |
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Pins Map
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This is the pins map for the CapTIvate board turned into a BoosterPack.
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Conclusion
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The CapTIvate is very efficient in sorting signal from noise, and touch from proximity. The evaluation kit is a clear example of a programmable sensor, with all the tools to customise the MSP430FR2633 to fit specific needs.
As a programmable sensor, software is key. The flow of data is very wordy and requires fast decoding. I expect the register option to reduce the flow of data but it isn't available yet. Similarly, the CapTIvate Design Center GUI generates the code for the sensor but I wish it could write the library for the master as well. I really like this bundle. Texas Instruments provides an excellent bundle of hardware, software and documentation. There's even a Workshop (Getting Started)! |
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Pros
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Cons
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Wrap-Up
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