I2C Hardware & PCB Design - Phil's Lab #132

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00:00 Introduction

01:50 PCBWay

02:33 I2C Basics
07:19 Bus Capacitance
11:15 Pull-Up Resistors
18:29 Repeaters, Level Shifters, and Multiplexers
21:06 Schematic Tips
25:16 PCB Design Tips

34:20 Outro

[BHSAHFAD]

I just checked the latest schematic of a working PCB I made about a few weeks ago, I am using a BME280 with a ESP8266EX and I use a 12K pull up resistor on SCK and SDI. I did it to save on a BOM line because I was using 12K for the ESP8266EX's RES12K pin. Phil, I need to tell you this, I appreciate your videos, when you make videos you talk about things that actually matter. I thoroughly enjoy the videos you make, keep them coming.

[LiviuGelea]

This is perfect timing. I actuqally need to read about I2C for my current project. This gives me a great starting point.

[JeremySeitz]

I have been using the TCA9517 I2C level-shifting bus repeater with success on my I2C projects. I'm doing some challenging things, connecting 16 LED drivers at a time on the same bus, sometimes over wires 50-100cm and with this chip, it works. With the level shifting I can power boards individually and not worry about mismatch, thanks to level shifting. They are only about $0.30 each, so I add them to all my boards. It also removes the problem of worrying about pull-up resistor values, as the segments in the I2C bus are isolated.

[FightSurvive]

Keep it up Phil ;) Again, teaching the next generation more than any US college could hope to.

[SAS-Technical]

I gained a lot of knowledge as a beginner. Phil, I am grateful for the video.

[konturgestalter]

I am planning to watch all 132 episodes.... cannot wait for more to come. learnt all my practical knowledge from you so far

[scottduckworth]

A BOM consolidation trick that I recently discovered: use 5.1k resistors as your i2c pull-ups. 5.1k is also common with USB-C CC lines to get a 5V supply, so you may already have them on your board.

This is working for me on a 5V i2c bus with one device and relatively short traces, operating at 400kHz. I haven't actually measured the rise time, but I have looked at the signal on a scope and it seems to have a decent Vhi setup time... and since it's working I didn't dig into it too much. If it hadn't worked then I'd just fall back to 100kHz (faster is nice to have, but not critical in my application).

[ArifKhan-bpzx]

Can't wait for similar video for SPI bus interface. Great Work...

[rraheem_p]

Funny how I was reading about I2C just last night and the 3 videos you showed were the ones I watched. Good stuff, keep it up 👍

[curtkeisler]

Thank you Phil for doing this video I've had all of these questions and you answered every single one of them. I've been intimidated by doing a lot of i2c across multiple components and now I feel like I can experiment more without having to worry about a lot of things. Thank you for the wonderful references to authorities if I want to dive in. This was the perfect video. Can't thank you enough!

[kiprof]

Great video about I2C Phil! Your explanations and examples really helped me. Thank you so much for your effort!

[milanvdzanden]

Working with I2C on my current project, excited to get some quality information from you on it 😊

[highchiller]

I am still waiting for a new USB 3.0-Hub with USB-C video from you that I would love to see. Not only for impedance matching questions but also if it includes power delivery, it gives me some headaches when it goes up to 20V. But for now, I enjoy this side deep dive into I2C. Always a joy listening to your guides.

[rohithkumar]

Beautifully explained!, thank you very much!

[kristianvk]

Great videos once again!!! :D
Im work parttime in a startup doing the electronics and your videos help out so much to get good habits and know-how.
Can you by any chance do a video how you structure electronics projects for large-scale operations like block diagrams, organization libraries, technical drawings, block diagrams, etc.
Basically how to keep the electronics neat when working across professions?

[TheOleHermit]

Thanks, Pkil. I'm adding I2C to my Teensy Laser Synth to control lumia projector gizmos, but don't really know what I'm doing. Your videos are spot on 🎯 and have been valuable guidance throughout my entire dev process.

[case_sensitive]

"preferably read before bedtime", haha 😂. I think that's the first time I've heard a joke on one of your videos

[jdarnell]

Phil, you rock the damn house and ALL of your vids are great. 🙂 Stay awesome!!

[ashchap]

Another thing to check is whether a device has internal pullup resistors. A lot of micros have configurable pullups.

[AhmadAsmndr]

Thank you very much, like always very informative.