It's very rewarding to watch your systematic work and reasoning during the whole construction phase. From idea to the final tests. Well done James, well done 🙂
So great to see Snek being played with the controller, with PCBs completed. Glad you took the time to fix LEDs...that was so frustrating to see that happen, but that's what revisions are for :)
Yay, another James video. According to the dates of the comments I really should become a patreon. Never be ashamed of bodges, have you seen the 80s mass produced computers? Many with factory made bodges for months or even years. Bodges are just a part of making new computers.
It really isn't necessary. At the moment I'm experimenting with making video's public at the same time as I upload the next video. That way I avoid spending two evening watching the stats and replying to comments.
I like to complain about PCB designs people do, so let's go... 1. Don't leave copper pours with single via (32:52) - it acts as antenna and your board becomes a nice radio. 2. Traces / components should be at least 2-3mm from boards edge (with exception for angled connectors) 3. Board edge should be protected by chassis ground ring (on each single layer) that is stitched together with vias. This reduces edge fired emissions. 4. Thin long ground pours also acts as antennas (ref. point 1, 32:30) 5. Components should be placed at least 1mm away from other components in low density designs [34:12, capacitor and SOIC14 IC] 6. Each PWR/SIG via should have GND via placed at lumped distance - it improves signal integrity and is necessary at high frequencies (and in power-spike-sensitive circuits) 7. In two-layer designs never cross signals at angle other than 90 degrees (bottom/top layer). Otherwise they will couple together causing interference. 8. If you've space use that space - place traces as far away as possible. 9. Always name your nets (makes it easier to understand your work when PCBs arrive :D). 10. Use colors - it makes routing way easier (especially to have custom color for each power network / GND and high speed signal or parallel bus). There're other issues, but those are the most significant ones. Your design is not bad (as it's low frequency, so it works fine. It's just an "future problem" pretender - it's better to learn proper design rules from "beginning" than to implement them later on).
Well, if you like to complain about ropey PCB design you have come to the right place. I’m a rank amateur (with a working circuit!). Whist I know I have a lot to learn about pcb design I can find many breaches of your rules on commercial pcb’s within arms reach, they are not universally followed! I often get conflicting advice in the comments of videos and it’s not easy to determine who I should listen to. You might be interested to know the schematic is open source, you are welcome to make improvements yourself. It would actually be interesting to make comparisons between my work and the circuit revised by an expert, I would get some test gear on it and hopefully see tangible differences!
@@weirdboyjim Okay, sent you an improved version via OSHW Lab messages (User Center). It's not best way to do it, but acceptable for hobby-grade design. (sorry for GDrive link, can't upload to OSHW Lab from my EDA :sad_face:). Btw. I'm not an expert. I just spent way too much time watching "proper circuit design" videos from reputable sources (eg. Altium Academy). On those frequencies differences are hard to see without research-grade hardware, however it quickly becomes an issue (at about >100MHz signals). I always prefer "futureproof" learning (as it's easier to learn how to do things properly rather than to implement countermeasures when issues arrive). And commercial PCBs often breach rules, because it's made to be the cheapest possible PCB, even if it sometimes violate local regulations (IIRC our gov tested extension cords and 80-90% weren't complying to EU standards - aka were illegal to sell). Chinese companies design things "just to work", safety and standards... who would care. That's the reason why I always check newly purchased device for proper grounding of metal parts... (which are usually not grouded at all). If you're looking for good resources on PCB design search for Altium Academy and Phil's Lab. Those are best sources on RU-vid.
Nice looking board James. Don’t forget to add the missing link to the backplane schematic and layout now, because when you come to make an integrated backplane that correction will be easily forgotten. Ask me how I know these things 😊
@@weirdboyjim Understand, although it would be conceptually cleaner to have only one interface type. What SPI interface chip would you use to interface the SNES interface to SPI, or would you do that with TTL logic?
Huzzah! This is a great step toward making a retro style game console, that's also a general purpose computer with a tty. I wonder what it would take to make an emulator for this board, once it's all said and done. That would give people a reason to write code for it, and you could run it on hardware (as well as anyone who can be bothered to duplicate your boards). I'm not suggesting you write it, but it would make a cool project. Imagine if you had a C compiler back end as well.
If you have silkscreen on bare copper, they will not silkscreen print that, so you could have let it like you had it the first time. No use for that information now, but good to know for in the future ;) Nice build btw!
@@weirdboyjim I also not put silkscreen on bare copper. Just because it is not good practice. And it if I do, the design will not look like the final board, which I don't like :) But it is good to know that it is ok if you do it by mistake.
Yes you can, but it’s only really practical on boards with a solder mask. Repulsion from the mask and attraction to the metal parts seems almost magical at times, be very careful about how much solder you put on and check carefully for bridges before powering on.
I really dont like the select and start buttons being so high up. Ideally they should go below the Right and X Leds. But thats only cosmetic (and will forever trigger my ocd). You might be able to squeeze the 3 lines going through the perfect spot in between the led pads.
Morning James, any reason why the final peripheral back plain there couldn’t be more than one SNES input board for multi player games, should any arise that is?
You could do that but I wasn't planning on it. Would be more interesting to adapt the board to support 2 controllers, you could share some components. This was an interesting circuit as it has some states and variety of components but if I wanted a second controller the easiest thing would be to put some extra wires into gpio lines and bit bang it.
I hadn’t thought of that, have a two controller board and share some of the circuit between the two rather than having two separate but identical boards.
If you put a polarizing filter in front of the light, and another one in front of the camera, rotated 90degrees, it might help reduce the reflections? Honestly though I don't think it's that bad, at least not in this video.
That's a clever idea, I actually tried that a while back and it works but it has a drawback. It takes out all the reflections so you use the nice little sparkles of the solder pads etc.. The resulting footage feels flat to me so I'd rather find another way.
Oh noes! Glad you respun the PCB. Don't be too hard on yourself. This stuff happens. Look in anything electrical you've bought - bet the PCB isn't V1.0!
My youngest daughter got married on Saturday, I had a horrible chest infection since Saturday and now that I feel better I see this gem of a video in the series and all is well!
Your circuits are very hard to follow where they are just shown as individual chips and a global label. Have you thought of using a bus so you can follow the flow more easier. Would help with debugging the circuit as well?
It's really difficult to strike a balance on this. Remember most of this schematic is made in a corner window alongside the breadboard work. Something that many people applauded when I started doing it, but I don't want to jump into videos with a schematic that doesn't relate at all to the stuff people have seen me put together already.
@@weirdboyjim Having spent way too many years drawing schematics by hand I find it hard not to use buss for things like address, control and data . Made it easer to draw and follow the flow, the old thing of information flows in on the left and out on the right. The final circuits and PCB's were done by the drawing office. saved me having to know all the standards required for the PCB production etc. I love the videos, so will continue to pause them to get an understanding of the cct operation. keep them coming.
I double checked my original recording. Looks like I didn't select the option to specify serial location. I've done that before any they spotted it anyway but not in this case. It was still comfortably hidden by the connector though so no harm.
