5 ms·

This is a tangent, but having worked with digital circuits for 40 years, the improvements in chips have made circuit construction -- even breadboarding -- vastl

This is a tangent, but having worked with digital circuits for 40 years, the improvements in chips have made circuit construction -- even breadboarding -- vastly more forgiving than ever before. I've run 10 MHz clocks on breadboards and 100 MHz SPI bus on 2 layer boards that were not designed with extreme care. And, it's a fast precision ADC that's meeting its datasheet specs on that board. No doubt the parasitics and other nasties still come into play, but it's still amazing how much faster we can go before they start to bite.

akiselev 4y ago
It also helps a lot when you get a well made breadboard from BusBoard [1] instead of the Aliexpress special. [1] https://www.busboard.com/ https://www.busboard.com/
- analog31 4y ago
  I just get the ones that the EEs throw away when someone retires. ;-)
Teknoman117 4y ago
That's been a funny thing for me. I'm not an electrical engineer, at all. My electrical knowledge is an introductory electromagnetics course I had to take in college that I've mostly forgotten, reading/watching EEVblog, other internet sources, playing around with cheap and/or old parts, reading whatever I can find, etc. I've made some retrocomputing boards (<= 50 MHz) (8051, 286, 68010, 68030, etc.) and haven't had much of a problem. No idea what the EMI looks like though. Greatest goof I had so far was an old part who's datasheet didn't mention that the signal output was open collector so I had to bodge a resistor in. Mostly just followed advice I found on the internet -> 4 layer boards can be had for very cheap these days (JLCPCB does 10 for $30 w/ ENIG boards up to 10cm x 10cm), so I followed the "just do yourself a favor and get the 4 layers boards so you can make ground and power planes" advice. Used a tool to compute minimum trace spacing to stay under a certain capacitance for a specific copper weight, board thickness, dielectric type, etc. Probably my crowning achievement at this point is making an 1.8V LVDS to TMDS level shifter board so I can get HDMI 1.2a (4x 1.65 Gbps lanes + sidebands) out of an FPGA board I repurposed from some cryptomining hardware I bought on eBay. Had to learn how to do soldering using a stencil, paste, hot air station, and a hotplate because no one is hand soldering 0.4mm QFN packages. 0402 are the smallest thing I can do by hand. Next thing I want to try is breaking out a small BGA. Managed to get a few Lattice iCE40HX8K's in the CT256 package (256 balls @ 0.8mm pitch BGA). What hurts is how patent/royalty/industry interest group encumbered that nearly everything modern is. Want to do PCIe? Join PCIe SIG. Want to do USB? Join USB-IF. Want to support SD cards? Pay a bunch to SDA. Actually their patents expired so maybe you can do native SD mode now without much fear. HDMI is awful, DisplayPort requires you to join VESA, MIPI for CSI and DSI devices, etc.
- analog31 4y ago
  Yeah, joining the clubs is burdensome. I'm lucky to be in an industry where there's enough value-add, that we just pay the piper and move on. Myself, I buy that kind of stuff pre-integrated.
  - Teknoman117 4y ago
    I mean, it's the same for me, I'm just on the software side of the company (mostly, I'd say systems because occasionally I have to borrow the PCIe packet analyzer to figure out why something isn't working). The electronics are a thing I do as a hobby and I try my absolute hardest to ensure work and hobby resources are kept separate. Electronics is sufficiently different from my professional role that it doesn't feel draining as a thing to do on the side. I'm not one of those "spend 8 hours programming/architecting/designing at work only to go home and spend another 6 writing code for fun" kind of people. I definitely write software and learn at home from time to time, but the motivation for doing it on the side is certainly less than it was before I turned it into a full time job. So I tend to gravitate towards things that are interesting to me but not necessarily useful to others.
- phlipski 4y ago
  "Want to do PCIe? Join PCIe SIG. Want to do USB? Join USB-IF..." As someone who works for a large silicon vendor I can tell you that even with access to those industry groups the documentation still sucks!!!! I look at the amazing documentation available surrounding various software initiatives (OpenCV, machine learning, linux drivers, programming languages, etc...) with envy. It's all right there and out in the open with multiple blogs and forums and pages explaining shit. And actually I did try to learn PCIe. I gave up. 1000+ reference specs, about 3 random web pages and a half dozen marketing youtube video's. There's a reason why some guys manage to build niche careers around these HW topics!
  - analog31 4y ago
    It blew my mind that the microcontroller I'm now using has a 1000+ page datasheet.
alar44 4y ago
I've been doing multi chip stuff with 16MHz Atmels with no issues just using a de-coupleing cap on the Vins. Did it not used to be that easy?
- relaxing 4y ago
  You say multi chip, but what are the signals going between chips? Imagine all the peripherals baked into your uc were separate DIPs, and you had to worry about high speed signals going everywhere. And yeah, all the parts were less robust and hadn’t evolved to be tolerant of less than perfect conditions.
  - alar44 4y ago
    You're right, the chips are not speaking 16MHz to each other. I've always revered the computing era where the electrical engineering actually mattered. Cheers.
auxym 4y ago
Listening to various Rick Hartley talks on youtube, I got the understanding that it was the opposite: even at slow clock rates, modern ICs cause all sorts of signal integrity and EMI issues because of very fast edge rise times. Cannot confirm from my experience though, I don't practice EE, I just dabbble in electronics and never actually characterized SI and EMI in my creations.

akiselev 4y ago

It also helps a lot when you get a well made breadboard from BusBoard [1] instead of the Aliexpress special. [1] https://www.busboard.com/ https://www.busboard.com/

analog31 4y ago
I just get the ones that the EEs throw away when someone retires. ;-)

Teknoman117 4y ago

That's been a funny thing for me. I'm not an electrical engineer, at all. My electrical knowledge is an introductory electromagnetics course I had to take in college that I've mostly forgotten, reading/watching EEVblog, other internet sources, playing around with cheap and/or old parts, reading whatever I can find, etc. I've made some retrocomputing boards (<= 50 MHz) (8051, 286, 68010, 68030, etc.) and haven't had much of a problem. No idea what the EMI looks like though. Greatest goof I had so far was an old part who's datasheet didn't mention that the signal output was open collector so I had to bodge a resistor in. Mostly just followed advice I found on the internet -> 4 layer boards can be had for very cheap these days (JLCPCB does 10 for $30 w/ ENIG boards up to 10cm x 10cm), so I followed the "just do yourself a favor and get the 4 layers boards so you can make ground and power planes" advice. Used a tool to compute minimum trace spacing to stay under a certain capacitance for a specific copper weight, board thickness, dielectric type, etc. Probably my crowning achievement at this point is making an 1.8V LVDS to TMDS level shifter board so I can get HDMI 1.2a (4x 1.65 Gbps lanes + sidebands) out of an FPGA board I repurposed from some cryptomining hardware I bought on eBay. Had to learn how to do soldering using a stencil, paste, hot air station, and a hotplate because no one is hand soldering 0.4mm QFN packages. 0402 are the smallest thing I can do by hand. Next thing I want to try is breaking out a small BGA. Managed to get a few Lattice iCE40HX8K's in the CT256 package (256 balls @ 0.8mm pitch BGA). What hurts is how patent/royalty/industry interest group encumbered that nearly everything modern is. Want to do PCIe? Join PCIe SIG. Want to do USB? Join USB-IF. Want to support SD cards? Pay a bunch to SDA. Actually their patents expired so maybe you can do native SD mode now without much fear. HDMI is awful, DisplayPort requires you to join VESA, MIPI for CSI and DSI devices, etc.

analog31 4y ago
Yeah, joining the clubs is burdensome. I'm lucky to be in an industry where there's enough value-add, that we just pay the piper and move on. Myself, I buy that kind of stuff pre-integrated.
- Teknoman117 4y ago
  I mean, it's the same for me, I'm just on the software side of the company (mostly, I'd say systems because occasionally I have to borrow the PCIe packet analyzer to figure out why something isn't working). The electronics are a thing I do as a hobby and I try my absolute hardest to ensure work and hobby resources are kept separate. Electronics is sufficiently different from my professional role that it doesn't feel draining as a thing to do on the side. I'm not one of those "spend 8 hours programming/architecting/designing at work only to go home and spend another 6 writing code for fun" kind of people. I definitely write software and learn at home from time to time, but the motivation for doing it on the side is certainly less than it was before I turned it into a full time job. So I tend to gravitate towards things that are interesting to me but not necessarily useful to others.
phlipski 4y ago
"Want to do PCIe? Join PCIe SIG. Want to do USB? Join USB-IF..." As someone who works for a large silicon vendor I can tell you that even with access to those industry groups the documentation still sucks!!!! I look at the amazing documentation available surrounding various software initiatives (OpenCV, machine learning, linux drivers, programming languages, etc...) with envy. It's all right there and out in the open with multiple blogs and forums and pages explaining shit. And actually I did try to learn PCIe. I gave up. 1000+ reference specs, about 3 random web pages and a half dozen marketing youtube video's. There's a reason why some guys manage to build niche careers around these HW topics!
- analog31 4y ago
  It blew my mind that the microcontroller I'm now using has a 1000+ page datasheet.

alar44 4y ago

I've been doing multi chip stuff with 16MHz Atmels with no issues just using a de-coupleing cap on the Vins. Did it not used to be that easy?

relaxing 4y ago
You say multi chip, but what are the signals going between chips? Imagine all the peripherals baked into your uc were separate DIPs, and you had to worry about high speed signals going everywhere. And yeah, all the parts were less robust and hadn’t evolved to be tolerant of less than perfect conditions.
- alar44 4y ago
  You're right, the chips are not speaking 16MHz to each other. I've always revered the computing era where the electrical engineering actually mattered. Cheers.

auxym 4y ago

Listening to various Rick Hartley talks on youtube, I got the understanding that it was the opposite: even at slow clock rates, modern ICs cause all sorts of signal integrity and EMI issues because of very fast edge rise times. Cannot confirm from my experience though, I don't practice EE, I just dabbble in electronics and never actually characterized SI and EMI in my creations.