Hi ...
I'm evaluating a MSP430G2553 in respect to a particular touch application. Key to the success of the product is fast measurement time, low noise and high sensitivity.
Desired measurement time: ~1ms
Noise: <5 values
Sensitivity is a bit hard to describe, but the resulting S/N ratio should be >5 ...
The 'RO_PINOSC_TA0_WDTp' used for the 'Capacitive Touch BoosterPack for the LaunchPad' has an OK S/N ratio, but the measurement time is much too long. In the attached file the 'fRO_PINOSC_TA0_TA1' method is tested, but the noise is much too high. A few Excel sheets are also included - these show the touch performance for:
Fast RO (capture_fRO_2.5ms_sample_time_touched.xlsx) - noisy and strange spikes
RO (capture_RO_touched.xlsx) - nice but slow
RO with different scan time (capture_RO_WDTp_GATE_512_touched.xlsx) - resolution low
Should I try a different measurement method, or is there something I'm doing wrong? Any info and/or help will be greatly appreciated ...
Kind regards Jesper