FS: Custom "Arduino UNO" compatible boards designed and mfg. by me. - Page 1
Forum section: electronics / general

author: RogueBotix
author_rank: Contributor
timestamp: January 11, 2019, 08:41:40 pm
content: I decided to re-design the Arduino uno board. I made a few design changes such as changing the usb chip so the board works well with USB 3. I also switch to a different regulator circuit so that the Arduino can happily run in a 24volt system. As well as a few other minor layout changes such as moving the pin 13 led and rx/tx right in front of their respective place on the header. The board uses high quality ceramic decoupling capacitors, so there are no electrolytics to dry out, and the board is assembled with eutectic lead solder, so it will not be subject to all the short comings of lead free solder such as: tin whiskers and mechanical fatigue.I wanted to sell a high quality board, that was made in the USA, and would last virtually forever. I decided I should do all the production myself. I bought a Quad IVc pick and place, and a MiniPak wave soldering machine. So they were designed and assembled by me.I am trying to sell them on ebay. currently I am selling them for the same price as the Adafruit boards. Please give me feedback, and if you would like, buy a boardhttps://www.ebay.com/itm/292886783729Thank you so much

author: sokoloff
author_rank: Super Contributor
timestamp: January 11, 2019, 09:01:33 pm
content: You probably need at least 29V and ideally 32V max input voltage to use on 24V (automotive, trucking, airplane) systems.In any case, 26V is definitely not high enough for a charging lead acid battery of 12 cells, which is the overwhelmingly common 24V case.

author: RogueBotix
author_rank: Contributor
timestamp: January 11, 2019, 09:07:06 pm
content: The regulator is designed for 24v systems, it has a 40v operating limit.

author: mbest
author_rank: Contributor
timestamp: January 11, 2019, 09:41:56 pm
content: Could use another photo towards the connectors on the end.

author: RogueBotix
author_rank: Contributor
timestamp: January 11, 2019, 09:47:57 pm
content: The USB and power jack? They are standard from a normal Arduino, but I will definitely add a picture tomorrow. Thank you for your feedback.

author: janoc
author_rank: Super Contributor
timestamp: January 11, 2019, 10:00:09 pm
content: Careful about calling it "Arduino". That is trademarked and the Arduino AG will go after you for trademark infringement once they catch the wind of this. They are known for enforcing their marks.The design of Arduinos is fair game but not the name. That's why Sparkfun calls theirs "Redboard" and Adafruit sells "MetroX" boards, even though they are clones of Arduino Uno.

author: sokoloff
author_rank: Super Contributor
timestamp: January 11, 2019, 10:08:52 pm
content: Quote from: RogueBotix on January 11, 2019, 09:07:06 pmThat's great!!Your Ebay listing though, says:QuoteTypo on quality, USB, and suggests a spec of 26V upper limit.

author: RogueBotix
author_rank: Contributor
timestamp: January 11, 2019, 10:12:19 pm
content: I didn't actually put Arduino on the board it self, I have however been putting it in the titles. What do you suggest I put in the title? Would it be ok if I put "Clone" After the word Arduino? Thanks for your feedback!

author: RogueBotix
author_rank: Contributor
timestamp: January 11, 2019, 10:15:06 pm
content: Quote from: sokoloff on January 11, 2019, 10:08:52 pmThank you so much! I observed your suggestion.

author: RogueBotix
author_rank: Contributor
timestamp: January 11, 2019, 10:42:22 pm
content: Quote from: blueskull on January 11, 2019, 10:35:31 pmI Revised it. Thanks!

author: janoc
author_rank: Super Contributor
timestamp: January 11, 2019, 11:28:39 pm
content: Quote from: RogueBotix on January 11, 2019, 10:42:22 pmEven better - create your own name for the boards. If it says only "Arduino-compatible", they could still send you a legal nastygram claiming that you are trying to profit from their trademark. If it says instead something like "SomeDuino 1 (compatible with Arduino Uno)" then you will likely be in the clear. I believe they even have a guide somewhere on their website that says what is OK and what is not with regards to the "Arduino" name and what you need to do if you want to make/sell own boards based on their designs.EDIT: here it is:https://www.arduino.cc/en/Trademark/HomePageQuoteSo you must not put Arduino-compatible in the title but it may be in the description. Plus a few of the other formalities.

author: Inverted18650
author_rank: Frequent Contributor
timestamp: January 11, 2019, 11:41:22 pm
content: Great idea and I will buy a couple to test in the 24V DIY BMS projects I have laying around. Nice work and thanks for sharing.

author: Nusa
author_rank: Super Contributor
timestamp: January 11, 2019, 11:55:00 pm
content: If it's got a usb2 jack, in what way does it support usb3?

author: RogueBotix
author_rank: Contributor
timestamp: January 11, 2019, 11:59:35 pm
content: Quote from: Nusa on January 11, 2019, 11:55:00 pmThe Blue USB ports on computers are USB 3. These boards work with the USB 3.0 ports

author: Nusa
author_rank: Super Contributor
timestamp: January 12, 2019, 12:13:10 am
content: Quote from: RogueBotix on January 11, 2019, 11:59:35 pmMeaning that some usb 3.0 implementations fucked up the 2.0 support? Haven't run into that problem personally.Anyway, the way you have it worded now, wouldn't surprise me if someone returned it for not having a usb 3 port.

author: sokoloff
author_rank: Super Contributor
timestamp: January 12, 2019, 12:14:14 am
content: Quote from: RogueBotix on January 11, 2019, 10:15:06 pmIt looks like the listing still suggests a 26V max input voltage at the top. That's not enough for a 24V vehicle (which runs at a nominal 28.8-ish volts).If the actual limit is 40V, why not suggest that as a limit?Similarly, listing still says "US 3.0, sporting a 26 volt upper limit", which I think should read "USB3.0, sporting a40volt upper limit"

author: Monkeh
author_rank: Super Contributor
timestamp: January 12, 2019, 12:59:38 am
content: The regulator shown does not support 40V operation..

author: Inverted18650
author_rank: Frequent Contributor
timestamp: January 12, 2019, 01:05:28 am
content: Quote from: Monkeh on January 12, 2019, 12:59:38 amSure as hell doesn't. 26V continuous, 60V transient.http://www.ti.com/lit/ds/symlink/lm2937.pdf

author: retrolefty
author_rank: Super Contributor
timestamp: January 12, 2019, 01:53:30 am
content: Interesting design. Using a switching regulator is a big improvement. I would have however preferred a USB micro or mini board connector, the old original USB connector is so big it sucks. I own probably 20 'arduino' boards using various AVR (168,328,1284, mega2560) chips mostly clones but a couple of real Arduino manufacture. However I never buy such a board that doesn't at least publish it's schematic. Doesn't have to be open sourced but a schematic drawing is a must.Do you have such a drawing to share? If not, why?

author: RogueBotix
author_rank: Contributor
timestamp: January 12, 2019, 02:46:15 am
content: Quote from: retrolefty on January 12, 2019, 01:53:30 amI'll publish the schematic, its on my computer at work.

author: bitseeker
author_rank: Super Contributor
timestamp: January 12, 2019, 07:32:06 am
content: Neat board. Seems to have generated a good bit of interest.How is the regulator mounted to the PCB? Is that a rivet? If so, it'd be nice to be able to more easily replace the regulator in case of an "input accident".Aesthetically, and perhaps even practically, it'd be beneficial to have pin 13's LED further from the connector like you did with the RX/TX ones. That way, its placement looks similar, the pin label can go back in line with its neighbors, and you can see the LED better from that side of the board. Not a big deal, but a nice tweak.For the photos, consider using a clean background (e.g., simple sheet of white or gray paper would suffice).

author: janoc
author_rank: Super Contributor
timestamp: January 12, 2019, 02:58:37 pm
content: Quote from: blueskull on January 12, 2019, 12:08:23 amWhy those requirement shouldn't be legitimate? What they are asking is completely reasonable, IMO. If you go to an IP lawyer with this you will only walk out $500 lighter for the "consultation" and still will have to do the above.The first 4 items follow directly from the fact that "Arduino" and the logos are protected marks. That's the trademark law imposing this, they are only making it clear for you. The rest is theirs requirements - but you ignore them at your own peril, people got sued/had legal problems for less when it came to trademarks (Sparkfun and Fluke's yellow multimeters come to mind).Your "stuff them" advice may work for someone in China but hardly for the OP who is in the US where Arduino has been suing people (and winning!) over their trademarks before.Risking a lawsuit (or at the very least having the auction pulled and potentially account banned by eBay) over something as idiotic as putting the "Arduino compatible" in the title of an auction instead of the description is just that - idiotic. It also gives anyone who would want to attack the OP over this a rather big "stick" because they could claim the OP acted in bad faith when they ignored even these very basic demands.

author: wraper
author_rank: Unknown
timestamp: January 12, 2019, 03:10:59 pm
content: Quote from: Nusa on January 12, 2019, 12:13:10 amMore like something fucked up on both ends. Because those ports work with other USB2.0 devices just fine. And it's not like silabs chip supports USB3, it just doesn't fail to work properly. Also what I can say with certainty is that original Arduino UNO has fucked up USB shield and ESD protection schematic. Designed by some idiot. It's so bad that ESD protection is not only non functional but MCU data pins can be fried through this "protection" if ESD hits the shield.

author: sokoloff
author_rank: Super Contributor
timestamp: January 12, 2019, 03:18:00 pm
content: Quote from: janoc on January 12, 2019, 02:58:37 pmI'm not convinced that the word "Arduino" cannot appear in the title (in the form/context of "Arduino compatible") of an auction or web page.I'm also not convinced that the last two items are absolutely mandatory in the form of compelled speech. (I agree that you can't suggest that you're part of Arduino project, but I would be willing to risk not saying that I wasn't part of it in every single piece of collateral.)I read these list of requirements as "if you do these, we won't bother you", but not "if you fail to do any of these, we will both bother you and we will win".

author: Nusa
author_rank: Super Contributor
timestamp: January 12, 2019, 03:18:48 pm
content: Quote from: janoc on January 12, 2019, 02:58:37 pmY'all must have missed the lawsuit over the Arduino trademark a couple years back between Arduino LLC (arduino.cc) and Arduino SRL (arduino.org). They ended it by forming a merged holding company, but the fight lasted for years. Given that history, I suspect the current company is quite willing to defend the Arduino trademark. The hardware is open source, no problem there, but they DO own the name.

author: wraper
author_rank: Unknown
timestamp: January 12, 2019, 03:54:53 pm
content: Quote from: janoc on January 12, 2019, 02:58:37 pmIt's not idiotic. Omitting arduino from title will produce much less hits from search results. It's called nominative fair use.https://en.wikipedia.org/wiki/Nominative_use

author: janoc
author_rank: Super Contributor
timestamp: January 12, 2019, 04:29:59 pm
content: Quote from: wraper on January 12, 2019, 03:54:53 pmSorry but nope. That is not fair use. You are literally exploiting someone else's reputation (= trademark) to sell your goods - i.e. exactly what the trademark is meant to prevent. That is why they make a distinction between putting the "Arduino compatible" in the title and in the description (the former not being OK, the latter yes).The criteria for the nominative fair use are as follows:QuoteThe first certainly isn't met and the second test maybe - even if the fonts aren't used, the word "Arduino" is trademarked by itself, not only when written in that specific font.

author: wraper
author_rank: Unknown
timestamp: January 12, 2019, 04:35:46 pm
content: Quote from: janoc on January 12, 2019, 04:29:59 pmSorry but yes. It's fair use. Using it for commercial reason does not prevent it from being fair use.QuoteThey are, especially obvious for second.

author: donotdespisethesnake
author_rank: Super Contributor
timestamp: January 12, 2019, 04:58:04 pm
content: Quote from: Nusa on January 12, 2019, 03:18:48 pmThat was completely different. It wasn't the original Arduino suing a cloner, it was the manufacturing arm of Arduino called Smart Projects which got sold to Federico Musto, who then renamed the company to "Arduino SRL" claimed exclusive manufacturing and sales rights to Arduino branded products,and sued the original Arduino designers (Arduino LLC).https://en.wikipedia.org/wiki/Arduino#Trademark_disputeIn fact, Arduino have never sued any cloners, although they did bitch quite a lot in the early days, they don't like it but are pretty resigned to it.As for not being able to use the word "Arduino" in a a listing, that''s just bollocks. As long youa) don't pass off your product as being made by Arduinob) call it something like "AVR board, compatible with Arduino Uno"c) ideally acknowledge the trademark "Arduino Uno is a trademark of Arduino AG"you will be on perfectly legal grounds, and no one from Arduino legal reps are going to write nasty letters or get your listing pulled.

author: MasterT
author_rank: Frequent Contributor
timestamp: January 12, 2019, 05:34:07 pm
content: High voltage input ( >12 V ) with linear regulator is a big mistake. I especially buy 7.5 V power supply for my projects, since arduino with a TFT / LCD shield is just overheating. I can't imagine arduino board is used w/o anything attached to it, and power dissipation could be a big problem.

author: RogueBotix
author_rank: Contributor
timestamp: January 12, 2019, 06:16:46 pm
content: More like something fucked up on both ends. Because those ports work with other USB2.0 devices just fine. And it's not like silabs chip supports USB3, it just doesn't fail to work properly.Do you think it is possible to add this kind of wordage in the description? Because thats what I was going for...Its just a bit to verbose to put that in a titleI have never had an Arduino work in usb 3 ports. And what inspired me to incorporate this is, one day my boss had bought and arduino and was just playing around with it, but was pissed off when it wouldn't work with his laptop that only had usb 3 ports.

author: bitseeker
author_rank: Super Contributor
timestamp: January 12, 2019, 06:19:47 pm
content: Yeah, I've run into USB2 devices that don't like USB3 ports. It's unfortunate, but it's a thing.

author: RogueBotix
author_rank: Contributor
timestamp: January 12, 2019, 06:39:07 pm
content: Quote from: MasterT on January 12, 2019, 05:34:07 pmIts not a linear regulator. If I run the voltage all the way up. The current draw does not increase at all, so then there no heat to be dissipated, making the board very efficient with power draw. The Regulator's heat is dissipated by a large copper plane on top and bottom of the PCB. The is a large hole underneath the regulator that solderes it to the copper plane when it goes through wave soldering. I do this all the time for the company I work for (my day job as an engineer). Heat sinks are expensive, and if you have the board real-estate, I can shave a ton of money off a board, saving them lots of money. You can also expose slits in the copper plane, so that when it gets soldered it creates "fins" made of solder.

author: wraper
author_rank: Unknown
timestamp: January 12, 2019, 07:04:56 pm
content: Quote from: RogueBotix on January 12, 2019, 06:39:07 pmYes it is linear regulator.QuoteExactly what happens with linear regulator.QuoteThere is. P=U*I. U (voltage drop over vreg) goes up and dissipated power goes up as well.

author: RogueBotix
author_rank: Contributor
timestamp: January 12, 2019, 07:17:04 pm
content: Power draw is the same from 5 volts to 26 when I plug it in to my lab supply. That will not be the case on a 7805 for example.

author: wraper
author_rank: Unknown
timestamp: January 12, 2019, 07:18:47 pm
content: Quote from: RogueBotix on January 12, 2019, 07:17:04 pmCurrent remains the same. Power goes up! If it was buck converter, current would go down as input voltage increases.QuoteYes it will be the case with 7805.

author: RogueBotix
author_rank: Contributor
timestamp: January 12, 2019, 07:34:22 pm
content: Quote from: wraper on January 12, 2019, 07:18:47 pmyup... You are a right, a VERY stupid mistake on my part..

author: MasterT
author_rank: Frequent Contributor
timestamp: January 12, 2019, 10:04:38 pm
content: I can't see right now on the official arduino UNO tech specification page how much current it's allowable for user to take out from +5V connector, to power up external shields, sensors, lcd etc. It was somewhere, 500 mA or so.But if a your board is gonna be arduino compatible, there should be some "power budget", at least 100 mA (about nokia 5110 consumed with back-light on).Have a look at arduino DUE schematic, switching regulator, and "huge" amount of current for external peripheral - 800 mA!https://store.arduino.cc/usa/arduino-due

author: Nusa
author_rank: Super Contributor
timestamp: January 12, 2019, 11:13:37 pm
content: Quote from: MasterT on January 12, 2019, 10:04:38 pmUNO product:https://store.arduino.cc/usa/arduino-uno-rev3I didn't bother with the text, I just looked at the schematic provided.The regulator on the official product is:https://www.mouser.com/ds/2/308/NCP1117-D-81326.pdf, which can provide at least 1000 mA. More if the input voltage is at the lower end of the range. Note that most UNO clones use a different cheaper regulator (or in OP's case, upgraded one), so don't try to apply official specs to clones.If you're powering the board from the USB port, then of course the USB 2.0 per-port spec of 500 mA applies. Some sources might do better than spec.

author: PlainName
author_rank: Super Contributor
timestamp: January 13, 2019, 07:08:51 am
content: QuoteSurely it should be irrelevant whether it could be legally enforced or not. The fact is that the Arduino chaps have kindly given you a massive leg up at no cost to yourself, and the minimum you could do in gratitude is conform to their request. After all, no-one is forcing you to nick their design and trade on their name.

author: macboy
author_rank: Super Contributor
timestamp: January 14, 2019, 07:32:52 pm
content: Two suggestions:- Some other Uno clones have an extra row of holes next to the headers. Usually these are populated with 0.1" headers, which makes it easy to connect F-F "dupont" cables to sensors, or a convenient place to attach a scope or logic probe. It is a nice thing that takes little board space and causes no routing grief.- Some other Uno clones have the USB-serial IC's handshake signals brought onto un-populated 0.1" pads near the IC. This is useful for adding hardware handshaking to the serial communication (it's a trivial software change once the hardware is connected).

author: RogueBotix
author_rank: Contributor
timestamp: January 15, 2019, 12:26:05 am
content: I really should before I starting building these, asked the community what would be good things to add, and suggestions...

author: bitseeker
author_rank: Super Contributor
timestamp: January 15, 2019, 01:17:06 am
content: Better late than never. I see a V2.0 in your future...

author: wraper
author_rank: Unknown
timestamp: January 15, 2019, 01:29:51 am
content: I personally would add ESD protection to USB and all MCU pins. Would make way harder to kill it, especially considering that most tinkerers don't really understand what they are doing. BTW it does not seem that you have proper circuit for USB/external power. It seems that attaching external power will result in outputting voltage to USB.

author: RogueBotix
author_rank: Contributor
timestamp: January 15, 2019, 01:52:20 am
content: As it is it cant put more than 5v into the usb with external power. Though if it were to be a problem I could add a steering diode. But if I starting adding tvs diodes to all of the micro's pins, that is gonna put this board in the spectrum of no one is gonna buy this.... As it is its hard to buy this when chineese arduinos are like 5$ I vowed to never buy one of those chineese arduinos again after my 3d printer's usb died partway into a 2 week print..I guess the most economical esd protection I could do would be put spark gaps on the board, which would help, maybe... nothing protects the end user someone from just grabbing the whole board and zapping something....

author: TK
author_rank: Super Contributor
timestamp: January 15, 2019, 02:03:48 am
content: I noticed some LEDs on the RX / TX pins... you need to be careful as they can have some side effects. RX / TX pins are not exclusively used for Serial, they should work as General I/O pins as well.

author: RogueBotix
author_rank: Contributor
timestamp: January 15, 2019, 02:10:18 am
content: Quote from: TK on January 15, 2019, 02:03:48 amPin 13 also has an led on it, that is also a feature arduino has and it is not a problem.

author: wraper
author_rank: Unknown
timestamp: January 15, 2019, 02:42:05 am
content: Quote from: RogueBotix on January 15, 2019, 01:52:20 amPowering USB is big a problem. You may even fry USB port of computer. Adding ESD protection for all ports would cost around $ 0.50-0.70 in parts. It's not about simply zapping. It would protect against many wrong things connected to the pins which otherwise would fry MCU.

author: wraper
author_rank: Unknown
timestamp: January 15, 2019, 02:46:09 am
content: BTW if you are concerned about cost, you'd better change vreg to something cheaper. At least add proper circuit for usb power like in original arduino. Cheap vreg+proper circuit would still cost less than single LM2937.

author: wraper
author_rank: Unknown
timestamp: January 15, 2019, 10:49:46 pm
content: About powering USB. Regardless of possible failures when computer is on, think what happens when computer is off. You will be dumping almost all of the current vreg outputs into USB port. Most likely there will be power switch/protection IC on +5V rail of usb. You will push current in reverse through that switch (body diode in mosfet).

author: RogueBotix
author_rank: Contributor
timestamp: January 16, 2019, 12:07:22 am
content: yes I get it.... there is some saving grace in that these all have a polyfuse on them. but yes I get it.

author: m98
author_rank: Frequent Contributor
timestamp: January 17, 2019, 12:54:18 am
content: What's going on with that layout? Only use 45° angles between traces and try to avoid unnecessary bends. The decoupling cap for U3 could also be closer. And having a good ground plane won't hurt.If you want some inspiration for a robust Arduino, look there:https://www.rugged-circuits.com/microcontroller-boards/ruggeduino-et-extended-temperature-40c-85c

author: RogueBotix
author_rank: Contributor
timestamp: January 17, 2019, 01:28:24 am
content: there is a huge ground plane for the cp2102, there are vias going to the bottom