# The Spark Gap - Episode 37

- Show: [The Spark Gap](https://hardwarepodcasts.com/podcast/the-spark-gap)
- Published: 2015-07-15
- Length: 1h 01m
- Page: https://hardwarepodcasts.com/podcast/the-spark-gap/2015-07-15-the-spark-gap-episode-37
- Listen: https://thesparkgap.net/the-spark-gap-episode-37

## Summary

Hosts Carl and Corey discuss designing embedded systems for the future, focusing on hardware strategies that allow for upgrades and revisions without redesigning the entire board. They highlight the use of surface mount test points for easier debugging and the PCA9540B I2C bus multiplexer to manage address conflicts and isolate faulty peripherals. The conversation emphasizes selecting pin-for-pin compatible components, such as Allwinner and STM32 microcontrollers, to enable cost-downs or performance upgrades later in the product lifecycle. Finally, they argue for leaving unused microcontroller pins accessible via headers and including bootloader support to ensure devices can receive firmware updates and remain useful over time.

## Chapters

- [0:00](https://hardwarepodcasts.com/podcast/the-spark-gap/2015-07-15-the-spark-gap-episode-37#t=0) Introduction: Surface Mount Test Points
- [6:35](https://hardwarepodcasts.com/podcast/the-spark-gap/2015-07-15-the-spark-gap-episode-37#t=395) PCA9540B I2C Bus Multiplexer
- [14:06](https://hardwarepodcasts.com/podcast/the-spark-gap/2015-07-15-the-spark-gap-episode-37#t=846) Pin-for-Pin Compatible Microcontrollers
- [25:51](https://hardwarepodcasts.com/podcast/the-spark-gap/2015-07-15-the-spark-gap-episode-37#t=1551) Firmware Upgrades and Flash Memory Sizing
- [37:07](https://hardwarepodcasts.com/podcast/the-spark-gap/2015-07-15-the-spark-gap-episode-37#t=2227) Open Source Tools and Future Proofing
- [42:19](https://hardwarepodcasts.com/podcast/the-spark-gap/2015-07-15-the-spark-gap-episode-37#t=2539) Breakout Headers and Unused Pins
- [50:53](https://hardwarepodcasts.com/podcast/the-spark-gap/2015-07-15-the-spark-gap-episode-37#t=3053) Hardware Identification Methods

## Topics

- [PCB design & layout](https://hardwarepodcasts.com/topic/pcb-design)
- [Microcontrollers & dev platforms](https://hardwarepodcasts.com/topic/microcontrollers-and-platforms)
- [Embedded firmware](https://hardwarepodcasts.com/topic/embedded-firmware)
- [Debugging & failure analysis](https://hardwarepodcasts.com/topic/debugging-and-failure-analysis)
- [Open-source hardware](https://hardwarepodcasts.com/topic/open-source-hardware)

## Most relevant to

makers and hobbyists

## Mentioned

- Keystone (other)
- Millmax (other)
- PCA9540B (chip)
- NXP (company)
- Allwinner (company)
- Olimex (company)
- STM32 (chip)
- ST (company)
- Pebble (product)
- Tesla (company)
- Arduino (product)
- Raspberry Pi (product)
- Altium Circuit Maker (tool)
- KiCad (tool)
- Eagle (tool)

## Related episodes from other shows

- [The Endless Y2K](https://hardwarepodcasts.com/podcast/the-amp-hour/2017-10-23-the-endless-y2k) (The Amp Hour)
- [Vertically Integrated Design Engineering](https://hardwarepodcasts.com/podcast/the-amp-hour/2019-08-05-vertically-integrated-design-engineering) (The Amp Hour)
- [167: All Aliens Are Shiny](https://hardwarepodcasts.com/podcast/embedded-fm/2016-09-07-167-all-aliens-are-shiny) (Embedded.fm)
- [328: Debugging Like a Monkey](https://hardwarepodcasts.com/podcast/embedded-fm/2020-04-23-328-debugging-like-a-monkey) (Embedded.fm)
- [Pseudo Code...Pseudo Good](https://hardwarepodcasts.com/podcast/the-amp-hour/2023-12-19-pseudo-code-pseudo-good) (The Amp Hour)

## Citing this page

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