Custom PnP Controller: The Final Chapter

The motherboard for the Index Pick and Place is pretty much done! Vacuum sensing finally works, it boots Marlin, and it looks frickin' rad. From here on out it's firmware tweaks and configuration. Feels good to finally have this finished!
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Index Pick and Place Github Repo:
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[@mikesnapper9001]

I don't need a PnP at all.. but because of your videos i reeeeeally want to build one now

[@fredo514]

If Arduino’s analogRead function has too much overhead for Marlin, you could try using the Stm32 DMA to offload the ADC read. Or better yet, pass the sensor output into a comparator or output compare pin to get a digital value when the pressure is below/above a threshold. You can get the comparison voltage from a simple voltage divider or use one of the MCU DAC to make it configurable. This way, checking if a part is picked up is only a matter of reading a pin state.

[@cheryldroffner443]

And you could add some hysteresis on the comparator as well. You shouldn’t have to do any ADC if all you need is blocked/unblocked and then it’s just a digital read. I enjoy your videos! Nice work!

[@fkiesel9442]

Most of the Arduino libs are made to be as simple as possible to use. Most peripheral libs simply start the operation, then wait until it is finished and then return the result. This way everything is very easy to use and no more advanced stuff like tasks or interrupts are required.

[@404Anymouse]

DMA is overkill. Most of the time using conversion_finished interrupt is perfectly adequate and non-blocking.

[@Kysen10]

stuff like this is why I don't bother with arduino at all and just program stm32 chips directly.

[@ericlotze7724]

I'm excited everything is coming together, this project has been amazing to follow!

[@Electheo]

Agreed!

[@BradParler]

Been watching this for a while and it's so over my head, but damn do I love how excited you get! Keep up the awesome work.

[@wizzardofwizzards]

The reference to "Programmable Air" was very insightful. Great presentation!

[@oneilgoisot9615]

in addition to the fact that you made an incredible work I really love how you made your videos it's always exciting and dynamic!

[@joshsmithbuilds2158]

Your excitement is contagious! Great job my dude.

[@radman999]

I love the style and music of your videos. It is really nice to see young people so creative and engaged. You inspire me to learn. Thank you so much Stephen.

[@mikeselectricstuff]

Vacuum sensing isn't really necessary as the vision will tell you if a part has dropped

[@olivervoss3196]

The pressure also drops measureably when the Part touches down on the pcb Giving you an indication and confirmation of good part placement

[@kraay89]

@@olivervoss3196 It's an indication of placement. Not necessarily _good_ placement ;-)

[@CruzMonrreal]

Seems like overkill when you could keep the sensing feedback loop on the MCU.

[@DominicClifton]

vacuum sensing saves a trip over to the camera, advance the feeder, retry, quicker...

[@Xanthyn]

Even when the content is over my head, I absolutely love the energy. I can't wait to see where the project goes, and I wouldn't be surprised if people are starting small businesses using this hardware when it is completed.

[@perceuk]

Love the enthusiasm, comm skill, dedication, production style, Stephen. Great channel: glad I stumbled into it 😊👍👏

[@ushiocheng]

Right on that soldering clip me: *how many PNP work have this human done to make a PNP machine* 😂 All engineers(including me): *Spend 12mo automating a task that can be done in 1 mo*

[@jorgepreciat2538]

You can put the ADC in free running mode and only read output registers when you need to. This would be orders of magnitude faster than the analorRead()

[@nikkismith8750]

Such a fantastic project - very well done Stephen! I really hope I'll be able to build an Index next year, budget permitting :)

[@andrewwalsh3744]

Just love what you are doing: It really is fantastic, and addictive to watch.

[@Kniffel101]

Your excitement is infective! Love your content! The hand flamethrower alone is super cool, but your whole channel is just a treasure trove of amazing and exciting projects! =O

[@igorbaranowski6367]

Awesome content as always!

[@mostrush4849]

Hey Stephon if you leave enough solder mask between chip pins while design and apply enough flux before soldering , you can do it right a way with just a single iron sweep without any bridges. you can learn more about it on Louis Rossman videos. I actually test it with a very chip iron and it works fine. Keep it in mind quality of flux is very important use MTech or some thing similar (I used Lotfett flux).

[@29C1C]

Also why use a conical tip? If u try a chisel head or a knife head or a flat sided “C” tip u will for sure find it easier, you would be able to solder in one touch without the need to use desoldering braid, also yeah Louis Rossman videos are so great to learn soldering

[@imjustabill247]

great filming and enthusiasm!

[@joao.vitorb]

Love your enthusiasm!

[@SpareChangeTV]

Gonna buy a bunch of PCB way stuff now thanks for introducing me to this company Stephen, their sponsorship is really paying off

[@curtisbeef]

Great work as usual. You should probably start getting Solder paste stencils(OSH stencils) and possibly a reflow/toaster oven to speed up building your boards.

[@Auzze]

Great stuff Stephen.

[@felipecarlin8540]

I wish KZbin recommended me this earlier. Awesome channel, awesome video, awesome you!

[@ViniciusCZanini]

Best project of 2020!!! I can’t wait to see maker’s all over the world using this cheap open source machine! Besides it is “cheap”, it has all the technology’s of the expensive ones. You’re the man! Great contribution! Thank you 🙏🏻

[@jimamos8960]

Looking forward to the "index" store so I can purchase this pre-built board and all the other boards I don't want to build. Also anxiously await the next session for all the physical tweaks and improvements... keep up the great work

[@ogurezzz]

Why are you use analog input whan you can use comparator? Do you need to measure vacuum or just detect that something was picked up? Anyway, GREAT WORK!

[@LaChaineDelEmbarque]

Agreed and 600mV will be read as low for a digital read on the stm32 and 3.1V as high

[@fkiesel9442]

At the end you are only interested if the threshold is met. But the threshold can be different for different nozzles. Probably an DAC could be used to adjust it as needed.

[@kraay89]

Because this way it's dynamic, which allow you to make changes down the road without having to redo your PCB.

[@olivervoss3196]

Can't wait to build my own PnP *-* You're just so inspiring

[@harshalnikhade7058]

Bro your channel should really grow. You make great content.

[@Karlemilstorm]

The ADC can run in continious mode in the background at very high frequencies. This means that you can read the a very recent value(maybe 1 microsecond old) sensor value instantly from the data register. It shouldn't be a problem to do so. But I don't know how Marlin is implemented. By the way. SUPER awesome video! I enjoyed every second!

[@idiotwithasolderingiron]

He remind me of me being a giddy little school girl whenever a project comes together love your enthusiasm really getting me that want to get back into creating I've been in a bit of a slump here lately but I think you're trying to pull me out keep up the hard work it is very inspiring

[@markustube]

Hey Stephen! It's been inspiring to watch this project come to life! I have a request for the next vid: could you spend 2 or 3 minutes discussing the state of the project overall? With videos coming every 2 weeks and focusing on one specific area, it's gotten difficult to glean where things stand in general. What are the big tasks that remain before the "2.0" that you mention in the FAQ? Would be really helpful for those of us who are following and hope to build one of these puppies in the near future!

[@brightnovastar]

Simply amazing

[@JonathanKayne]

Smart move to switch to instrumentation amplifiers. We learned about this in AC circuit analysis lab and trying to replicate the them using op amps is really difficult even if you are comfortable using analog circuitry since the resistors have to be tuned perfectly. We used them to make an EKG machine which also has to read a small differential voltage.

[@edgarsaenz7205]

Excelent Job!

[@joshhaughton1893]

The way you put the kiCad logo on the board is sick..

[@Graham_Wideman]

Stephen -- as others have mentioned, if A/D is going to be a hassle to integrate into Marlin's code, then you could instead just use a comparator to compare the (amplified) sensor voltage to a fixed threshold, producing a single bit to input to your MCU. You could use a DAC output to set that threshold, if you think it needs to be adjustable. That said, it would be nice to be able to log the pressure signal, as variations in that during p-n-p of different parts could help troubleshoot pickup and release issues that may occur at some point. Then again, if you're faced with such a troubleshooting task, you could always tap in a second pressure sensor and monitor it completely separately.

[@dr.n0n082]

It's awesome dude

[@videosforthegoodlife2253]

Fantastic!

[@AndreBandarra1]

Hey dude, been following the project for quite a while now but never commented, well done, this is awesome stuff! I'm always curious about your pcb holder mega screw thing :) so cool and practical! what is it?

[@fyremoon]

A low tech approach could be a plastic tube with a dried pea (or plastic pellet) inside it. When there is vacuum, the pea would rise inside the tube. Mount an optical sensor at the bottom and you know if you have vacuum or not, because the pea will be sucked up the tube by the vacuum if there is a seal and not move if there isn't one. It also gives you a visual that there is a problem.

[@sjgsteve21]

Wwwwwuuut is that desk PCB and pet holder Stephen has.??? “Ah Wyant Thayt”

[@streppa]

I'm in my 40s and just starting out with fabrication. You are an inspiration.

[@Adam-fe4lq]

Incredible video! Very informative and interesting to watch for someone like me with not much knowledge of this stuff!!!! Also, does anyone know what the soldering clamp/stand thing he is using actually is? I would love to get one as it looks much less annoying than those octopus clamping solutions.

[@kwakeham]

I was looking for a cheap digital vacuum sensing to do waterproof testing. What I've ended up with is an arduino shield that has two LPS22HB's Baro sensors. Since they are absolute, you can pull up to about 0.9 ATM vacuum on them. Very cheap in volume. ABS 3d printed tube mount + o-ring to PCB, but the PCB must not have via's through the area exposed to vacuum, and the thicker the pcb the better as mechanical flexing affected them a little. Worked a lot with strain gage Wheatstone bridges and have several ADC's I like with built in gain from maxim and TI. Makes the one your using another option for me.

[@FranzzInLove]

Instrumentation amplifier are hard to build by hand because they require precise matching of the resistors if u recall correctly

[@arjenhiemstra]

Nice update! Would it be an idea to include the diag pin from stepper drivers that have stallgaurd on the PCB? With that limit switches are not really needed anymore

[@stanislavsberesnevs704]

2:40 Like for the excess solder removal method.

[@PFBruno3]

Vacuum sensing would likely be more reliable if the sensor is up by the tip. Faster response because that whole length of tube back to the mobo needs to be evacuated with each cycle. Threshold should just be set there by a comparator and potentiometer, then output a digital output to the mobo.

[@vtrandal]

Absolutely love the work you are doing, but I’m curious why you chose to use Marlin? Because you wanted to design your own controller? And porting Marlin was ... [used in a previous project]. Congratulations on your success to date. Your gratitude to those that have helped you is refreshing. Thank you for sharing your journey.

[@marios2liquid]

You can also use a 16-18bit delta sigma i2c adc instead of an instrumentation amp + the random microcontroller's adc (different micros have different bits/vref/accuracy so not that portable). This also helps keep the analog stuff right at the origin which helps with shielding and stuff.. There are many simple ones like the MCP34xx or fancy ones like the ADS1115 which has programmable gain and other conditioning which is nice.. But not sure how the i2c stuff can be handled nicely in Marlin fw.. and speed of reading might be an issue too..

[@egidiusmengelberg6826]

Why do you still want to use Marlin? I think implementing all the extra functions in grbl would be a lot easier. I know there are gbrl stm32 versions with more axis than usual.

[@CruzMonrreal]

When prototyping, it's often quicker and easier to use what you know. He can probably switch to something more feature filled or simpler later.

[@qrcline]

You could use a comparator or a ADC for the vacuum sensor.

[@tobiaslinde84]

you could use an attiny as a dedicated ADC so you can read vacuum continusly

[@aterxter3437]

when will you pick and place the new main board with the older one ?

[@Pott_AV]

Yes a new video :D

[@draco5991rep]

Could you make a video (it doesn't need to be long) about the actual circuit that was designed for Programmable Air? Or does the PA Project have a detailed Documentation on their scematics?

[@ChrisFredriksson]

Hey Stephen, when will this version of the PCB be released? Would love to build one and try and help out with the software side on the board. Of course, there is you and probably others already on the board to testing and tweaking, but any way I could help and test it out? As always, love your videos and can't wait for new videos!

[@mattmoreira210]

0:24 a vacuum sensor? Like a rubber diaphragm pressing on a micro-switch?! Couldn't it be that simple?

[@CodyBelcher]

Why not add some descreat logic in the form of a comparitor high if over some voltage (I probably have the wrong term there) to convert the analog input to a digital input to make it easier to intergate into Marlin?

[@gentrix1990]

Great Videos! Im looking for the "third hand"-stand you are using but cant find it. What is it called? thanks it advance!

[@rambox11]

Omnivise Board Holder. They're on Amazon. Pretty expensive though

[@mosiyukvasil]

Anyway, I think that it will be much solid to place pressure sensor on separated PCB and move it on the carriage (expecting it will provide more correct information about pressure in nozzle)

[@shibbleswentworth]

i have no experience here but could you simply measure current pulled by the pump that creates the vacuum? Under a vacuum, the pump doesn't work as hard & current goes down and so you can just define the current threshold to denote high/low?

[@xxportalxx.]

That's a brilliant idea, would simplify things considerably.

[@nikkismith8750]

Has anyone put together a rough cost to build the latest version of the project? I can't find one on the github: there are a few different BOM files (without prices) but some are 6 months out of date

[@mosiyukvasil]

Hi, can you please and share a link on your PCB holder (metal cylinder with screw). Thanks

[@richardlighthouse5328]

How about op amp comparator to make analog signal into digital. You can set which point is on and off.

[@RoycePipkins]

I am not familiar with STM but in AVR, if you skip the blocking Arduino analogRead call and talk directly to the ADC hardware you can start an analog acquisition, go about the rest of your loop, and then poll for completion or get an interrupt later when the acquisition is complete. I am certain the STM ADC hardware is as or more capable than that. You'll just need to read the STM chip reference manual on how to talk directly to the ADC hardware. It won't be as easy as a quick call to analogRead, but it won't be that hard either.

[@mytendo3477]

If you can't read the analog voltage with the marlin firmware, you could add a comparator and set the threshold with a potentiometer, and just use a digital input. Maybe that works.

[@maxwelzig]

Hey, where do you buy your components from? Great video!

[@wi_zeus6798]

(at least some) from LCSC: kzbin.info/www/bejne/pJK9YYqwpdeSfs0

[@arvindaditya19]

Hey image processing happens in atmega2560 or in the pnp software that runs on the computer?

[@pedrocimini3040]

Why did you end up choosing this type of analog sensor instead of a digital I2C or SPI one like the bosch BMP280? Those are like $3 a pop

[@ericlotze7724]

Does the board support ODrive for the Axis, and if not how hard would it be for someone to add that? (ie could it be plugged to some port, or would it be hard pcb level stuff) ?

[@ericlotze7724]

I saw a video on the older design on odrive's yt channel "liteplacer" and it was f a s t . Granted m o n e e e, but for a makerspace or something the increased speed may be nice.

[@ericlotze7724]

12:50 probably answers that lol (askin before watchin tsk tsk @me)

[@oswynfaux]

Still have that vacuum pump next to the camera.

[@TheRainHarvester]

I think "unexpected maker" would like your machine!

[@AC0JK]

When will you update this board design and the new feeder design on github?

[@DavidKenny64]

Forgive me if you have already answered this, but why a vacuum sensor? You wouldn't have to have a hose to the board, and the expense of the vacuum sensor if you just load sensed the vacuum pump. You could do that with discrete components.

[@sagnikpradhan3594]

What was that music in the intro?

[@Roelasia]

is the whole project incl. pcb and so on open source ? if yes where to find it?

[@sm3vlc]

Have you thought about tray feeder and stick feeder yet? Not all components come on tape.

[@timberwolf1575]

Silly question: Why not just use one of the many atmospheric pressure sensors out there that reads out over the digital interface of your choice?

[@elorrambasdo5233]

If you make a another revision, use the PnP to make the next PnP for maximum existential friction

[@ericlotze7724]

Do you have a CNC PCB Mill yet? (or do you prefer etch resist-pens or 3d printed etch resist stencils? )

[@ericlotze7724]

Or just p c b w a y As well i guess lol, but local-fab/hardware testing is still neat imo

[@xxportalxx.]

I believe he already showed boards he'd milled himself. He's like sponsored by pcb way so why not get professional boards produced?

[@mikesnapper9001]

@@xxportalxx. that was with a mill he got from a sponsor for just like a month. But since hes sponsored by pcbway he can get his boars made and shipped and receive within like 4 or five days, probably for free since they sponsor him, so there would be no point in milling your own boards. Specially anything bigger than a simple breakout.

[@xxportalxx.]

@@mikesnapper9001 yep

[@ericlotze7724]

@@xxportalxx. Definitely, they seem to make very “finished/neat” boards, i love the black coating option

[@dimakrayushkin]

Small mistake: solder mask clearance is too high, so kicad just remove all solder mask bridges between fine ic pads (see 3:26). Set 'solder mask clearance ' to 0.05 mm (or just 0, as kicad recommended in recent versions). See 'Design rules//solder mask/paste'.

[@juniorlucival]

How about software and mcu firmware for this board?

[@donvukovic7440]

Is this stepper controller available separately ? Is there a link for just this PCB ?

[@cdyoutoob]

Expansion ports could support a joystick controller? SNES Controller perhaps?

[@TheRainHarvester]

They sell programmable resistors. Maybe that would allow dynamic range for the opAmp/pressure.

[@danedwards_ee]

or a comparator and pot.

[@TheRainHarvester]

@@danedwards_ee Yes, very true. But maybe dynamic changes could be useful: bigger components require more vacuum, or auto calibration if seals develop leaks. But not sure. (These cases aren't really convincing.)

[@champstyl]

why not measure the power drawn by the vacuum pump? under load/vacuum it should draw more power and u can kick the part from the BOM

[@kelna2]

This is what he should be doing. So much simpler, no fancy/hard to source sensors required, and it's really cheap. I'm using the ACS712 on one of my projects and it should work for Stephen as well if he is powering his vaccuum pump from his PCB it would be super simple add in. Fewer things for the end user to have to wire up too.

[@Graham_Wideman]

I guess measuring the pump motor current would work, but one reason not to go that path is that I suspect Stephen doesn't yet know whether this particular pump is going to be strong enough, once the PnP starts picking parts at some speed. So in the interests of being able to swap the pump easily, it makes sense to me to avoid that dependency, at least for now. It's not even clear that you want the vacuum pump responding on the fly to each pick-up. It might make more sense to have a bit of a reservoir which maintains a uniform upstream vacuum, (with the vac sensor tapping in to the vac line close to the PnP head. That also allows expansion to multiple heads at some point (given multiple sensors). And the pressure sensor is hardly "fancy/hard to source", you can get it at most of the main distributors.

[@kelna2]

@@Graham_Wideman Hmm yeah, I didn't think of that. It makes sense for sure to use a vacuum sensor if he's using a reservoir. I haven't worked with vacuums that much, but that seems more expensive than a direct vacuum from a pump. Do you think it's worth it?

[@Graham_Wideman]

@@kelna2 Oh I don't know that he's using a reservoir currently. However it's certainly a move that can become useful in pneumatic projects to gain consistency of operation. I was just listing some arguments in favor of decoupling the sensing of component pickup from the generation of the vacuum, at least until some experience has been gained. Make it work reliably first, then see what can be cut out -- that kind of idea.

[@motoday3580]

Красавчик , давай делай вещи!!!

[@crazor01]

Is there any place besides github to discuss this project? I'd like to build a machine loosely based on the index and contribute back to the project, so I wonder what chat/forum/group/discord/whateveritisthatscoolrightnow to join to engage with other contributors/users?

[@MarionMakarewicz]

Check video description for discord server.

[@crazor01]

@@MarionMakarewicz Funny. I did check the video description of this and one or two other videos yesterday and I swear I did not see that link ;)

[@arthurheito3867]

These boards you use are the Marlin firmware.

[@thewyliestcoyote]

What branch on github is the most up to date motherboard ?

[@amirhosseinarab272]

Please tell me how can I buy mobo revo motherboard?? Please someone tell me

[@angelovalerio9984]

Well done, your project is incredible. Let me know when you become the CEO of a company, I'll sure invest in it :)

[@rupantaradhikary1482]

you deserve a lot of likes

[@ericlotze7724]

Also for axis redesign (assuming this is in the mechanical bit?), this axis is pretty neat, and within reason "infinetly scalable": wiki.opensourceecology.org/wiki/Universal_CNC_Axis

[@xxportalxx.]

The issue I've had with machines using this type of axis is they tend to warp and twist

[@ericlotze7724]

@@xxportalxx. There was data on that, i think it occurred post 2 feet or so (1 meter definitely) There is a version with embiggened rods for things the size of the CNC torch table etc

[@xxportalxx.]

@@ericlotze7724 I've had versions shorter than that, and I'm really not impressed with what I've seen of them, they also have a habit of flexing considerably and inducing vibration in the process. I'd say using extrusion with rails or simply rollers is a far superior solution for not much more money

[@TheGg6422]

Where is schematic of MOBO REV002?

[@gergelymatesoveny8171]

i hope remodelling is because you switched to FreeCAD

[@mohamed_fawzy]

amazing bro👌❤️❤️❤️

[@idiotwithasolderingiron]

So basically what I'm gathering from this is your basically using Marlin firmware which is a 3D printing firmware so what you're really trying to say is I can do this using a 3D printer main board with just firmware changes interesting now I know that the 3D printer board it's not going to have the stepper IO quantity needed but it could be a good start for education I have a question is do I upgrade my 3D printer or do I scavenge it for parts and make a PNP