Forum Rule: Always post complete source code & details to reproduce any issue!
Results 1 to 21 of 21

Thread: Mini 3.2 - Made Teensy 3.2 smaller at 30.48mm x 12.98mm.

  1. #1

    Mini 3.2 - Made Teensy 3.2 smaller at 30.48mm x 12.98mm.

    Inspired by onehorse's project in the past I have designed a small module of Teensy 3.2 alike.
    You can download its Gerber files, schematic and BOM at the following link:
    << edit new link below >>

    Code:
    The link on PCBway.com has been changed to the following:
    pcbway.com/.../Miniaturization_of_Teensy_3_2_board.html
    You can download all BOM, SCH and PCB Gerber files.
    It may help the Teensy3.2 enter the market for small modules that Teensy family lacks.

    It's 100% open source and included for commercial use. I hope some forum members who have SMD assembly capability can make some for the community.
    I pre-ordered some MK20DK256VLH7 at Newark a while ago and it should be delivered in Dec. I can make them available to you. The price was much cheaper than what they are charging now.
    If nobody is interested, I will cancel the order before its delivery date.
    If anyone is interested in serving the community, please contact me at trainer4edu@gmail.com. I will help you as much as I can.
    Last edited by defragster; 11-25-2021 at 09:55 AM. Reason: Update link from p#20

  2. #2
    Since nobody is interested in this project so far I temporarily stopped sharing on the PCBway's site. I would like to clarify somethings before restarting it.

    1. Paul Stoffregen made a reference board to help his customers with their hardware design. This mini 3.2 board with a PJRC's bootloader is similar to the Paul Stoffregen's reference board on OSHpark. Isn't the OSHpark open source hardware?

    2. I am not interested in selling this board, but hope someone can make a few to be available for some forum members, not a big operation, but just for fun. Is this allowed? If not, I will not allow commercial use on this mini 3.2 board. Only DIY makers can make it for themselves, is that OK with you, Paul?

    Regards,

  3. #3
    Senior Member PaulStoffregen's Avatar
    Join Date
    Nov 2012
    Posts
    25,215
    First, quick disclaimer... this isn't "legal advice" (which generally comes from an attorney you've hired... not forum messages).

    PJRC does not restrict how you use the MKL02 bootloader chip. It is implicitly meant for you to make your own circuit boards, which you can share or sell however you like. Commercial use is fine. As far as PJRC is concerned, you can use it as part of your design, similar to any other electronic part you've purchased.

    While not strictly related to the bootloader chip, one point to consider is the software license terms for any libraries you use to create whatever application you program onto your boards. Nearly all the library code PJRC publishes which becomes part of your program has MIT license, which is a "permissive" license intended to allow you to publish you application with or without disclosing your own source code. However, libraries written by 3rd parties have their own license terms. For one example, the old Arduino SD library used before Teensyduino 1.54 was GPL, which does require source code sharing.

    So to (hopefully) answer your question, yes, it's ok with me if you share your circuit board design. There is no requirement, as far as PJRC is concerned, for your design to be "open source hardware" simply because you have used the bootloader chip we provide. In fact, as long as you're building them with genuine bootloader chips purchased from PJRC, (again, as far as I am concerned) you may manufacture and sell or share as many as you like, even on a commercial for-profit basis.

  4. #4
    Thanks Paul! I understand what you said. I thought that you could have changed the rules recently. Just wanted to double check it.
    Since the Mini 3.2 has your bootloader built-in, it's free for anyone to make and sell without restrictions. Anyone one uses the board and installs any unlicensed software, that's his or her problem, any OSH designer will have no control over that as you have no control over your reference board.

    I re-started sharing on the PCBway web site: See p#1
    I am not interested in making and selling it. Hopefully someone can do it for the community.
    Last edited by defragster; 11-25-2021 at 09:54 AM. Reason: edit out old link

  5. #5
    Senior Member pictographer's Avatar
    Join Date
    May 2013
    Location
    San Jose, CA
    Posts
    702
    Neat design! I hope people do buy or make some.

  6. #6
    Senior Member+ defragster's Avatar
    Join Date
    Feb 2015
    Posts
    15,265
    @FRDM4236 - Very cool looking little thing! SPI to a TFT pin order on one side, and i2c on the other.

    Update on a FRDM4236 board I had on hand ... soldered it to a new Lockable Beta PJRC T_4.0 unit to get usable SD card and the other bottom pads brought out to T_3.6 layout. PCB was the USB extended version - but the USB Host daughter board not built yet.

  7. #7
    @pictographer and @defragster - Thanks for the nice words. I do hope some one who has a reflow oven to make some. It's not too difficult. All parts in the BOM are cheap and you can get them from LCSC.com. The MK20DX256VLH and bootloader may be gotten from PJRC.com as a set in a small qty. https://www.pjrc.com/store/ic_mkl02.html

  8. #8
    There is not much interest in this product, the cost of making this board with a bootloader chip may be more than $20 for 5-10 pieces. This may not be feasible for anyone to make it. I removed it from sharing. The link to PCBway in this thread is disabled, you will only see an error message when you click the link.

    I think this pinout arrangement can help breadboarding by reducing wiring if you need to use a TFT display. I am thinking about moving it into different controllers, like Arduino D21, STM32F4 and RP2040, but I need help. If anyone would like to collaborate, please contact me at trainer4edu@gmail.com.

    Click image for larger version. 

Name:	mini32_42.jpg 
Views:	31 
Size:	143.7 KB 
ID:	26428

    Thank you all.

  9. #9
    Senior Member+ defragster's Avatar
    Join Date
    Feb 2015
    Posts
    15,265
    @FRDM4236 - Mini_t32 is an great creation and certainly a good solution with Teensy compatibility and T_3.2 power far in advance of anything AVR or other things that size.

    Given it looks like you built some out and it is a tested reference design - that only works when paired with a PJRC bootloader, not sure why it needs to be taken down. Though hacking to a Debugger interface probably only a few pins away - but then it is no better than the other mcu's for programmability.

    Those other mcu's seem fun - but an esp32 with that format could be good or better? But antenna and support chips tend back to 0.7" like this tinypico.com/ and his variants.

  10. #10
    Quote Originally Posted by FRDM4236 View Post
    There is not much interest in this product
    I am interested, but I did not see this thread until today. Can you leave it up for a couple of weeks and give people a chance to look at it?

  11. #11
    @defragster - Thank you again for the kind words. The SWD interface pads on this prototype are used for my testing only. They were removed from the Geber files that I published.
    I would like to find which part caused the problem if my board did not work. When a board was not working I would check the microcontroller via SWD interface, if the micro is bad then I replace it, or if the bootloader is bad, most likely is from cold solder joints.

    The three reasons to take it down:
    1. It does not seem to be a board that many Teensy enthusiasts wanted.
    2. If someone duplicates the bootloader, (I am sure the security fuse is blown on the bootloader, but you never know what hackers will do), you may see illegal mini 3.2 on the market.
    3. The cost is prohibitive. The micro costs about $10 now in small qty., the bootloader is $6.8 plus other parts and SMD assembly labor, it's well over $20 in cost. The only way to make it alive is if PJRC.com can make some for the community, or it sells the bootloader and micro at a discount price to help a seller.

    You got me excited on the TinyPico. I have not paid any attention on ESP32 in recent years. After checking its schematic and saw the picture, I maybe able to fit it into the Mini 3.2 size. The ESP32 chip is only 7mmx7mm, much smaller than the 20DX256, so it will fit 0.4" width. On the mini 3.2, the traces are >6mil except a very few at 6mil, the via holes are 12mm/24mm, so there will be more space if the traces can go to 5mm/5mm and holes to 10mil/20mil. The CP2104 can be replaced by a CH340E, it's a smaller part than the CP2104.
    Resistors can go down to 0201 if needed. The USB jack will be a micro USB, not type C.


    @joepasquariello - Thanks for your interested in the Mini 3.2, I can email you the Gerber file, SCH and BOM tomorrow, I will put assembly instructions on my web site soon.

  12. #12
    Senior Member
    Join Date
    Mar 2017
    Location
    Oakland, CA, USA
    Posts
    348
    Regarding #2, PJRC already publishes the full Teensy 3.2 schematics: https://www.pjrc.com/teensy/schematic.html

    What would be the harm with leaving this up? It’s a learning opportunity for others, I think. You could always put a disclaimer that it might be expensive to build or something. Having said that, I’d also love to see it. I think it’s really neat and I’d like to learn more about what it takes to put a board together. (You can find my email here: https://github.com/ssilverman/QNEthernet.)

  13. #13
    @shawn - I could not find your email address at github, could you please PM me your email address? I will send all files out to you. I just did it to @joepasquariello
    When I see more forum members request files, then I will post it online.

    @defragster - To put the TinyPICO in the mini32 size is very doable if I put the PSRAM on the solder side. The PSRAM can be an option. Most applications may not need it.
    The 3.3V LDO is very tiny and I did not put it in.
    Click image for larger version. 

Name:	TinyPICO_alike.png 
Views:	9 
Size:	16.9 KB 
ID:	26447
    I will make a big reference board first, after it all tested OK, then I will put it into the mini32 size. Compared to the TinyPICO, it will have a smaller size and pinouts for TFT and OLED displays.

    If anybody likes this project then we can collaborate, even make it as a community board, but I don't see the possibility. This forum is a software forum for the Teensy boards. I will have to move it to the ESP32 forum. Thanks for your suggestion.

  14. #14
    Senior Member
    Join Date
    Mar 2017
    Location
    Oakland, CA, USA
    Posts
    348
    Cool, thanks! I used the “send email” link and not the “private message” link. (My email can also be found in either library.json or library.properties of that repo, for future reference.) Thanks for a wonderfully instructive project.

  15. #15
    Quote Originally Posted by FRDM4236 View Post
    If anybody likes this project then we can collaborate, even make it as a community board, but I don't see the possibility. This forum is a software forum for the Teensy boards. I will have to move it to the ESP32 forum.
    This is not only a software forum, and people are telling you they are interested. I don't understand why you keep saying collaboration is not possible.

  16. #16
    Senior Member PaulStoffregen's Avatar
    Join Date
    Nov 2012
    Posts
    25,215
    I hope you'll decide to share the info again.

    Manufacturing pretty much anything in very small quantity is expensive. Component costs at low quantity is always more expensive, because of fixed costs in handling and processing orders. If a total build cost at only 1, 5, or 10 pieces competitive with volume manufacturing were a hard requirement, pretty much nobody would ever share any hardware project on an open source basis.

    Likewise for "interest", a few days or 1 week is unrealistic. Building community takes time. Growing a user base is a very slow process. These things take sustained & usually thankless effort over a long period of time.

    Even if you're not going to put in that daily or weekly effort, what's the harm in just sharing the info with a link to however you want people who are interested to communicate?

  17. #17
    Yes Sir, I will do it, it's an honor to have your encouragement.
    I will post all assembly instructions online tonight and upload Gerber files to OSHpark. The cost is only about $3 including shipping at OSHpark.

  18. #18
    I just uploaded all files necessary for making this project.

    The Gerber files can be downloaded from OSHpark

    https://oshpark.com/shared_projects/3lU6j4S5 The Mini T3.2 board

    https://oshpark.com/shared_projects/kjFjK3cl The label sheet

    Assembly instructions are available at:
    https://www.trainer4edu.com/edubase_.../mini_t32.html

  19. #19
    Very clever design!

  20. #20
    @joepasquariello - Thanks for your kind words. Sorry for the late reply. I have been working on my TinyPICO very hard.

    The link on PCBway.com has been changed to the following:
    https://www.pcbway.com/project/share...3_2_board.html.
    You can download all BOM, SCH and PCB Gerber files.

  21. #21
    Quote Originally Posted by FRDM4236 View Post
    The link on PCBway.com has been changed to the following:
    https://www.pcbway.com/project/share...3_2_board.html.
    You can download all BOM, SCH and PCB Gerber files.
    Thanks very much. Sounds like you're getting a lot done.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •