#250

[@kayferrari5361]

Loved that video Mick thanks. It also answered a question i had which is, "if one of the led's stops working does it stop the whole show?", and i see it doesn't. Because one of your green ones had blown but the red one worked ok. (8 across 5 down the green led is broken) I loved these video's Mick. They've helped me so much and given me so much to ponder on. Thanks.

[@MickMake]

Thanks mate!

[@kayferrari5361]

I've paused the video around 6:50 - can anybody tell me why the voltage of the first board was 5.12 volts and the second board was 5.07 volts - why dont they all read the same?

[@MickMake]

It all comes down to tolerances. Resistors and capacitors especially all have a certain tolerance. I used 5% tolerance components and so you will see a variance.

[@kayferrari5361]

@@MickMake Oh i see, wow. That's beautiful. Thank you.

[@wilyartihoward2005]

I had no idea how PCBs are made! Cool videos, I'm still stuck in software land!

[@Thomas-ob5fe]

Hi Mick, nice job for such a hurry. May i suggest if you're going to design Rev2, besides breaking out those lovely GPIO's, could you consider to move the JST Connector to the side (almost to the border) that piggi-strapping the battery onto the PCB gets possible?

[@MickMake]

I’m actually thinking of adding an 18650 battery holder instead, but yes... good point.

[@JanCiger]

@MickMake Are you sure that the Pi Zero W has 5V tolerant GPIO? If you make those STAT1/STAT2 pins higher than 3.3V you will likely cause a latchup and can destroy the pin driver there. If you are going to respin this, I would add at least a clamping diode on those pins to be on the safe side.

[@KeanM]

Yeah, I don't recall them being 5V tolerant. A current limiting resistor in series at least, if not a level shifter.

[@MickMake]

Yes true. I’ll have to fix that one as well!

[@tomgeorge3726]

Yay.. ROADTRIP!!!!!!!

[@electronic7979]

Excellent

[@punit_patel]

Schematic and layout review is most important thing.😌

[@MickMake]

Yes indeed!

[@KeanM]

@@MickMake I suspect an ERC check in Eagle would have picked this up?

[@punit_patel]

@@KeanM ERC does not pick human error like net name change, symbol and footprint miss match (happens to me). It only tells you about unconnected pins, pin type miss match(power, input, output) etc.

[@KeanM]

@@punit_patel Actually, In this case I'm pretty sure Eagle ERC would have shown him "Only one pin on net 5.0V"

[@punit_patel]

Haven't use eagle since Autodesk takeover. But in kicad ERC never give error or warning but good thing is it has same net on 3.3v and 3v3 like symbols.

[@AJB2K3]

4th row down, 8th from the left. Green LED not working.

[@kayferrari5361]

First time i've seen a "bodgewire". As you can tell i'm an absolute beginner to electronics but i'd like to ask anybody - when using a bodgewire, can you use any thickness of wire? Can you use a single strand of wire as thin as those in earphones or will it get hot? And, by using too thick of a wire will it drain the battery quicker or make the board hotter if it's plugged in? Thanks in advance.

[@MickMake]

In this case I could have use a single strand of that wire as it was just a low current low frequency signal. Had it been used for power then I’d need to use a much thicker wire. It all comes down to current carrying capability.

[@kayferrari5361]

@@MickMake Nice - thanks Mick

[@KeanM]

Bodge wires are suprisingly common, even on production devices, and are used when the labour cost to add the wire(s) is less than the cost to remake the PCBs. Most commonly they're made with thin "kynar" wire (which used to be commonly used for wire-wrap connections), assuming low current. Obviously the next revision of the PCB will correct for it, but sometimes the required change is discovered quite late in the production process. FYI, the wire thickness affects its resistance (less surface area for the electrons to move about). So a thin wire carrying a high current will get hot much quicker than a fatter (or multi-strand) wire.

[@kayferrari5361]

@@KeanM Thanks Kean, informative and interesting. Amazing to think they'd have a team of solderers adding bodgewires to 5000 boards. Id love to do that for a job for a while. I take it thinner multistrand wires are more resistant than a thicker kynar single strand. Nice.

[@sharedinventions]

It might also be a good idea to place some test-points on the PCB, they are also great for modding. :)

[@MickMake]

Yes true!

[@timmy7201]

Where to find a pick and place machine in Australia: "Up in the bush"!

[@Martin-DL]

Really great video for us makers. Thanks! Can you provide some information on your inspection microscope? And please ask you "crumpy" friend for the type of the stencil holder to apply the solder paste to the pcb.

[@tinygriffy]

The Microscope setup is nice, with the giant monitor and lag free.. wow ! i like to know about it too, i still use a jeweler magnifying glass, these things you wear like a hat.. dunno what its called.

[@MickMake]

MickMakeMail #25 had the microscope. A really nice cheap Chinese one. The TV is there with an HDMI switcher so that I can connect up a whole bunch of things. Having a huge display is so much better!

[@MickMake]

As for the stencil holder. I’m sure +Kean Maizels will respond.

[@KeanM]

That would be "grumpy" not "crumpy" :D The stencil holder I have is a "Hanail HN3040B manual precision printing table". I can't find any info on this exact one, but it is basically the same as a lot of other 300x400 stencil holders. Search for "YX3040" on AliExpress to find a bunch that are very similar. They're not cheap because they have a lot of metal in them and weigh quite a lot (35kg). FYI, I use the same ADSM302 microscopes in my office and love them when using via HDMI. I previously had the ADSM201 which wasn't bad. Both are shown in MickMake Mail 25.

[@MickMake]

Well, sometimes you are crumpy after an all-nighter. :-)

[@takisbakalis]

but did you sell these?

[@butterylabs]

To be fair, I haven’t really seen him grumpy =)

[@MickMake]

No, he’s OK. Like all Ozzies there’s always a bit of banter between mates.

[@KeanM]

Haha, I guess I can be - especially when someone I won't mention doesn't clean up after himself :)

[@_who_cares_1123]

10:48 The one led (C8, R4) not lighting up green triggers me.

[@MickMake]

Yeah, annoying isn’t it?!

[@ליהיימליך]

wow, that's a great video!

[@AJB2K3]

One of your green leds were not working!

[@panikrev175]

Adam Bryant Thanks for pointing out a problem, but not telling anyone where it is.... It’s at Column 8, Row 4. Your welcome!

[@AJB2K3]

@@panikrev175 err lol, I was being vague in case he had already spotted it! BTW, I can't count when I'm drunk!

[@MickMake]

Yup, a cheap LED strip from eBay!

[@izzieb]

Like the SpongeBob narrator reference.

[@avejst]

Nice, thanks for sharing :-)

[@killmechanizm2424]

everyone is driving on the wrong side of the road

[@tinygriffy]

Haha i had to think of Treebeard ... "don't be hasty, barumm" Maybe its time to setup prototyping at home, you have a nice new lab and some space ... :) With some routine you can easily prototype such a board in 4 hours (printing foils, exposing, developing, etching) Okay, drilling and soldering the vias is a little bit of pain but its a one time thing so ... I wish i had a rivet machine for these ^^ i do have a box with really nice looking PCBs at home from the time i didn't do it myself which i can glue to the wall for looksies XD. (There is a smiley there but i don't really think its funny, because its a waste of time, money and resources getting boards back you cannot use (thinking of myself there, no offense intended)). Good thing only one botch fixed your board ! Something i would like to hear more about is the process of selling it at tindie, especially shipping costs and taxes / customs fees, packaging and shipping etc. .. how to calculate the overall cost / price. I know they have a nice documentation, but I think there is much more to it than they write in their docs. Maybe you already did that video, but i'm too lazy to search right now :see_no_evil: Anyhow, really nice video series, thanks Mick !! Keep em coming ! *dreaming of the 3d printer that does the job... sigh*

[@MickMake]

Yup, I was being hasty, but that was the goal... see what I could do in a week. I used to make my own boards, but I don’t any more, because with people like JLCPCB around it just doesn’t make sense to do it yourself anymore. For example; the 90 boards I made were so cheap I probably won’t ever use and just make another batch with the fixes.

[@tinygriffy]

@@MickMake Its true, Chinese PCB fabs are cheap, and fast, and mostly of good quality. Anyhow, you succeeded in proving the point.. Its possible to fab 90 PCBs in a week, I couldn't do that in my cucumber glasses at home ;D. Its really nice for makers and tinkerers to have that nowadays ! Though environmental issues should be a concern in my opinion . Would be nice to have really easy to use spice software, like ltspice without the hassle of setting it up, sort of a "just drop your schematics in" solution.

[@martkt10]

Grumpy

[@KeanM]

I was mainly grumpy because someone kept saying the word "grumpy".

[@jameslamb4573]

C'mon, Ku-ring-gai is "Skippy" country. Edit: LED (8,4) ???

[@MickMake]

Yes LED, but picked up on it too late to fix that mistake in post. And yes skippy country. Should do a gag on it. Just have to find. Some fake kangaroo paws.

[@minhdang6502]

Please don't use a BSS138 n mosfet for driving ws2812b strip. It will never work since it can't transfer enough power signal for the LEDs. I tried this with ESP8266 and 5m long strip and it doesn't run properly. Highly recommend reading this article happyinmotion.com/?p=1247 for what logic level converter for this type of work load.

[@str0g]

Speaking of components, it would be interesting talk about how good components from China are in comparison to digikey or mouser. Maybe Dave Jones could help u.

[@MickMake]

It all comes down to tolerances essentially, but it’d be great to do some comparison tests with at least basic jellybean components.

[@tinygriffy]

Who is Dave Jones ? (just kidding) I think the rule of thumb here is "you get what you pay for" I stopped using cheap parts from china (ordered on ebay) some time ago now. I had really bad experiences with sk6812 LEDs and tp4056 charge controllers for example. the leds (single colours) just died after couple hours and the controllers .. some get really .. really really warm, not the best thing to put next to your lipo. Since then i order at mouser (digikey element14 and some others are also there ), never had trouble with anything anymore.

[@mmvblog]

You drive in the wrong side! Ah, you’re on the wrong side of the planet ... so from my point of view it’s the actually correct side, just the wrong direction.

[@MickMake]

Sometimes the cars fall off the road. You gotta be careful of that.

[@Martin-DL]

Ah, finally I understand why you call it "downunder"

[@kayferrari5361]

Markus that's what i thought and maybe i've been drinking too much, but my mind was put to rest when i started seeing kangeroos bouncing round on their heads ;)