# The Spark Gap - Episode 50

- Show: [The Spark Gap](https://hardwarepodcasts.com/podcast/the-spark-gap)
- Published: 2016-11-09
- Length: 1h 39m
- Page: https://hardwarepodcasts.com/podcast/the-spark-gap/2016-11-09-the-spark-gap-episode-50
- Listen: https://thesparkgap.net/the-spark-gap-episode-50

## Summary

Hosts Carl and Corey discuss user input methods, starting with the LTC4366 surge stopper for managing in-rush current and the FTDI FT900 series microcontroller, which features a proprietary core and shadow memory. They then analyze tactile buttons, explaining mechanical bounce and debouncing techniques using capacitors and firmware counters. The conversation covers rotary encoders, distinguishing between incremental (quadrature) and discrete (Gray code) types, before concluding with resistive and capacitive touch sensing technologies, including the Silicon Labs CPT007B chip.

## Chapters

- [0:00](https://hardwarepodcasts.com/podcast/the-spark-gap/2016-11-09-the-spark-gap-episode-50#t=0) Introduction: User Input Methods
- [1:36](https://hardwarepodcasts.com/podcast/the-spark-gap/2016-11-09-the-spark-gap-episode-50#t=96) LTC4366 Surge Stopper and In-Rush Current
- [11:57](https://hardwarepodcasts.com/podcast/the-spark-gap/2016-11-09-the-spark-gap-episode-50#t=717) FTDI FT900 Series Microcontroller and Shadow Memory
- [30:00](https://hardwarepodcasts.com/podcast/the-spark-gap/2016-11-09-the-spark-gap-episode-50#t=1800) Tactile Buttons, Switch Types, and Debouncing
- [47:22](https://hardwarepodcasts.com/podcast/the-spark-gap/2016-11-09-the-spark-gap-episode-50#t=2842) Rotary Encoders: Quadrature and Gray Code
- [1:18:51](https://hardwarepodcasts.com/podcast/the-spark-gap/2016-11-09-the-spark-gap-episode-50#t=4731) Resistive and Capacitive Touch Sensing
- [1:28:37](https://hardwarepodcasts.com/podcast/the-spark-gap/2016-11-09-the-spark-gap-episode-50#t=5317) Silicon Labs CPT007B Touch Controller
- [1:37:33](https://hardwarepodcasts.com/podcast/the-spark-gap/2016-11-09-the-spark-gap-episode-50#t=5853) Conclusion and Audience Feedback

## Topics

- [Analog & power electronics](https://hardwarepodcasts.com/topic/analog-and-power-electronics)
- [Microcontrollers & dev platforms](https://hardwarepodcasts.com/topic/microcontrollers-and-platforms)
- [Sensors & measurement in products](https://hardwarepodcasts.com/topic/sensors)
- [Embedded firmware](https://hardwarepodcasts.com/topic/embedded-firmware)
- [PCB design & layout](https://hardwarepodcasts.com/topic/pcb-design)
- [Chips, FPGAs & semiconductors](https://hardwarepodcasts.com/topic/chips-and-fpgas)

## Most relevant to

makers and hobbyists

## Mentioned

- LTC4366 (chip)
- FTDI (company)
- FT900 (chip)
- ESP32 (chip)
- Silicon Labs (company)
- CPT007B (chip)
- Maxim (company)
- Espressif (company)
- Cadence (company)
- STM (company)
- NXP (company)
- Qualcomm (company)
- MIPS (other)
- ARM (other)
- Arduino (other)
- Raspberry Pi (other)

## Related episodes from other shows

- [523: Bad Experience With Donuts](https://hardwarepodcasts.com/podcast/embedded-fm/2026-04-02-523-bad-experience-with-donuts) (Embedded.fm)
- [469: Saving the World Is Not a Hobby](https://hardwarepodcasts.com/podcast/embedded-fm/2024-01-28-469-saving-the-world-is-not-a-hobby) (Embedded.fm)
- [Ep051: Pointing With Your Tongue, C64 Touchpad, USB Killcord, and Audacity Does Everything](https://hardwarepodcasts.com/podcast/hackaday-podcast/2020-01-24-ep051-pointing-with-your-tongue-c64-touchpad-usb-killcord-and-audacity-does-ever) (Hackaday Podcast)
- [Chairs, Sparks and Devices - Optional Olent Obreption](https://hardwarepodcasts.com/podcast/the-amp-hour/2014-04-01-chairs-sparks-and-devices-optional-olent-obreption) (The Amp Hour)
- [379: Monstrous Cable Corporation](https://hardwarepodcasts.com/podcast/embedded-fm/2021-07-08-379-monstrous-cable-corporation) (Embedded.fm)

## Citing this page

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