Thanks sir i have watched many videos on PCB Designing but did not understand properly but when i watched your vidoes i understand everything about PCB Designing and enjoyed alot i have no words about your method of teaching many many thanks
As always, I'm very happy to watch these videos where you explain important things with care and patience. I'm very thankful to you. I can't afford your courses, but I hope your business goes extremely well.
Really great video - I learnt most of this the hard way, but i decided to register and visit your fedevel site more regularly. Thanks again for all of your content.
Good work RF, I recently went through your "Learn to Design your Own boards" course from udemy. Its very informative and definitely deserves five star rating.
THANK YOU!!! This knowledge and tips are so helpful. Better than finding out about these concepts the hard way once the smoke comes out. Thank you thank you thank you. These are great fro what I'm trying to do.
Hi sir, I am very excited at every video that you upload I do have a small request Can you upload a video on IPC Standards for a proper PCB design development and manufacturing
Excellent video. I particularly found your tips on avoiding cross-talk interesting. I'm going to research the 22ohm series resistor on the clock line (I haven't noticed this before). Anyway, thanks! I learnt lots!
Darian Cabot If you found the crosstalk topic interesting, have a look at this online crosstalk calculator and put there some numbers from your existing design. You may be surprised about the results: www.eeweb.com/toolbox/microstrip-crosstalk
ilkay C I did not mention impedance matching, as it's very hard to do for 2 Layer PCB (no solid reference plane, too thick dielectricum => too wide tracks). But you have a very good point - impedance matching is very important.
Pleased to see your tutorial and am expecting more. Could you please explain about using the atmega16U2. I was thinking of using the FT232R but the atmel seems to be cheaper.
Great and informative Video. I am going through your video "Learn to Design your Own boards" course from udemy. In this course, What i like most is : special attention given to power supply section pins. VCC, AVCC, AREF...( use of decoupling capacitor and FB ). After completion of this course , I would like to design a board based on ATMEGA32A , as I need more pins for my project. Need help and suggestion : MY Question is: Can I apply all these 14 TIPS , power supply section etc to ATMEGA32A design ? Can you please share something or schematic diagram or any "link" for atmega32A for reference design ? Please create another course for any other microcontroller like atmega32A, atmega2560, atmega2561 ?
Robert, thank you very much for amazing video with lots of information. I'd like to know what are the factors that we have to consider while creating a board size and shape.
you all prolly dont give a damn but does someone know a tool to log back into an instagram account..? I was dumb lost the login password. I appreciate any assistance you can offer me!
@Dominick Kohen i really appreciate your reply. I got to the site on google and im waiting for the hacking stuff now. I see it takes a while so I will reply here later when my account password hopefully is recovered.
I never burn the bootloader to the 328p chip because it wastes 1.2 seconds to boot up time and it waste valuable space on the chip. Instead I burn the final HEX file direct to the chip without the bootloader, the chip starts up much faster.
Fantastic! This is just what I was looking for. I like that you take the time to explain the reason behind each PCB design tip. I just subscribed to your channel. Hope you can make more videos on real products and then give design tips to improve them. Thank You.
I wonder what for on the arduino have 2 oscilators and what is sad 328P have not a cristal oscilators. I thing this one cristal near 16U2 could be used fo tactile 328P as well
Hey Robert, I've been looking at your 28 pins Arduino circuit. The reset circuit doesn't make sense to me. Shouldn't "U6" be an OR gate instead of the AND listed in your schematic? If it's an AND gate how does the 328 microcontroller reset? -Jake
RESET is LOW active. I used AND gate to be sure, that if one of the input signals is LOW (or both are LOW), then output is LOW. It means, if reset button is LOW or AUTORESET is low (or both are low), then RESET is LOW
The modern chips have build in basic ESD protection. Often the ESD chips are placed on real world connectors which are going to be accessible when your board is build inside a box or on interfaces which are going to be connected for example from other computers. Theoretically, it could be useful to place external ESD protection on the pins, however if you are connecting these pins to other circuits (e.g. breadboard with some components), normally it may not be necessary.
These videos are great thanks for taking the time to do them, they help! Can I ask what your thoughts are on Altium Circuit Maker? If it's any good I am hoping to convert to it from DesignSpark. In the future could you do the same video for the MSP430F5529 launchpad? Thanks again I've been learning a lot about PCB layout because of this channel :)
wussup331 Thank you :) I am very happy you like the videos. According to Circuit Maker - I have not had any chance to try it. I did register on their website, but I have never received anything back. And, I will think about taking a video about other development kits :) Have a nice day, Robert
Robert Feranec Altium could dominate the hobbyist market with this, it's just they decided to make it cloud based with libraries linked to octopart - so there is no ability to make custom parts and footprints from what I understand which would kill it for me. They are moving to open beta in a few weeks, would be good to hear your thoughts on it if you have time.
reset capacitor istn't needed anymore, because nowadays AVRs do have brown-out-detection ... in the old days, it was used for power-on-reset, but this times changed.
Theoretically yes, practically it is safer to keep the circuit. I have seen a lot of boards with RESET problems (including recent boards), so you really want to keep an option to play with the RESET signal in case of problems. For example, brown-out detection will not enable to tweak RESET time if needed. In some specific applications / connections you may need to keep RESET down for longer because some connected peripherals may require longer initialization. Also, if you do not need the reset circuit, you can just keep it unfitted. However, keeping this simple circuit can save you from making a new revision of your board.
And don't forget ultra-low power scenarios. Disabling the Brown-out detection saves a few uA. Really important if you want to power your device on a coin-cell for +10 years ;)
+Paulo Lopes: I just routed it as short as possible and broke 90 OHM impedance rule. It's not really possible to achieve nice and correct impedance on 2 layer PCB (the tracks would look weird).
+Robert Feranec: another question what if you use a bigger series resistor to match impedance? and this components to ground? what are they and they will not create a sub?
- series resistors are not substitution for track impedance - the components to ground are ESD protection, just google for CG0603MLC-05E (here you can find the full project, including schematic: www.28pins.com/)
+Robert Feranec : And if for example I have a 4-layer PCB (Signal GND POWER Signal) and somewhere i need to go from top layer to bottom layer (USB differential pair). In this case, the return path is broken, rigth?? What is your tip to solve this??
If you select a segment of a track in your PCB, when you press TAB, Altium will select segments of the track on the same layer and when you press TAB one more time, Altium will select all segments of that track (on all layers). I think, this doesn't work for very old Altium.
I also noticed a long time before, that the Arduino boards are routed really ugly, why didn't they put just a little bit more time in layouting such a mass production board ... don't get this at all. Are your Altium Files accessible somehow? just want to browse around on my own on this "pornographic" board .... really nice work!!
Vaander vald You can download the Altium files from GitHub - just click here: github.com/FEDEVEL/28pins/archive/V1I1.zip or if you would like to access all the files, including BOMs & Gerbers, register at www.28pins.com/ and download them here: www.28pins.com/?s2member_file_download=28Pins-Designed-by-FEDEVEL.zip&s2member_skip_confirmation
+InfinityOrchid Do you mean schotky diode D6? The purpose of this diode is to discharge capacitor C32 very quickly when board is powered off. If D6 was not there and you power OFF (disconnect input power) and then power ON (connect input power) of the board very quickly, the capacitor C32 would be still charged and reset would not work properly. Of course it depends on the internal circuit of the gate U6 (there probably is also a similar diode), but you never know for sure, so it's better to place D6 into schematic and if the internal U6 diode on pin 2 can be used, you just don't fit D6.
+Robert Feranec Thanks for the reply, Robert. I'm not used to seeing something being discharged to a positive power rail; I have usually seeing a capacitor discharges through a resistor to ground but, not to a positive power rail with the diode, like D6.
