New Gen3 Carrier for OneWire sensors

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#21

PCBs arrive tomorrow from JLCPCB! All the component reels are here. One lesson learned already is to double check the size of reels when ordering a full reel. The 470uF caps I knew were larger. I did not expect they’d arrive on a huge reel that won’t fit my PnP machine. No problem, I’ll just put them in the IC trays for picking since all my other components are reeled. I may even just end up placing this component by hand depending on how the PnP handles something that big. I’ll update tomorrow when the boards come in.


#22

First batch of boards and a stencil arrived, and I think they look great! I was little concerned with some of the pins on IC1, but looking back at the schematic, those pins are supposed to be bridged.


#23

@peekay123 I just realized I never addressed your comment. Thank you for the suggestion. Until you said this I did not even realize an I2C to OneWire bridge existed.

I have encountered first hand the issues with the OneWire libraries. I may switch to an I2C chip in the future, but with some of the changes suggested in this forum to the OneWire lib, my reliability has been around 90-95% on readings. As I incorporate more complex sensor types in the future, I’m sure I’ll need either a fixed library or an external chip.

EDIT: I’m starting to really warm to the idea of an I2C bridge, thinking about the 3 pins I could free up for other things. :slight_smile: That may be in version P3.


#24

First design mistake found! I haven’t put one together yet as I just got my work area set up (stencil printer, PnP, reflow oven). I designed this with three stereo jacks for OneWire sensors. I mistakenly used STX-3120-3BM, which is a switched mono 3.5mm jack. I ordered replacements (STX-3120-3B), which are non-switched stereo 3.5mm. Unfortunately they have one additional pin on the footprint that the 3BM doesn’t have, and I don’t see a stereo jack with the same footprint as the 3BM.

I’ll update the PCB design and send off for another batch of boards as soon as I get one fully assembled and tested in order to hopefully find the REST of my mistakes. :wink: This whole process has been difficult, but it’s been a great learning experience and definitely has gotten me out of my comfort zone! All the other projects I’ve done in the past were wire wrap on proto boards with through hole components. Yeah, I just dated myself there! lol

I’ll keep updating as I make more progress or find more errors in the design.