Is there a third Teensy 4.0 breakout board?

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MichaelMeissner

MichaelMeissner

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I've been following the process of the loglow breakout board:

And the second PCB designed by blackketter:

I'm wondering if somebody has designed a third board, more in the line of the FrankB board for 3.2 or the Bob Larkin board for 3.5/3.6:

In particular, it does not widen the Teensy (which allows for placement in smaller breadboard/prototype boards, and also to allow the Adafruit feather adapter to be installed), and it puts out the pins in two columns behind the Teensy. I've found that the Feather adapter has a little more than 0.2" between the Teensy and the battery charger (the battery charger is the main reason I like the feather adapter -- it is much sturdier than soldering a JST socket, and for battery projects it is easy to recharge the battery).

On the Teensy 4.0, to get access to the micro-SD card, you would solder in a FFC 8 pin header to allow connecting the micro SD drive to another header and use the flat 8 pin FFC cable.
 
Michael,
I'm very frustrated. I want/need to get going with using the T4 in real tasks, but unless I can get at all those pins, I'm stuck. I started to build a prototyping board this morning using the loglow beta breakout, but the thought that because that there is no assurance that the footprint will not change, I now question whether it is wise to go ahead.

I was going to wait for my .8mm versions of my modded blackketter's board to arrive before ordering thicker ones, but now I think I'll just get them into the pipeline at OSH right away.

I've also been toying with the idea of taking the castellated cut-outs of blackketter and creating a new board with loglow's DIP footprint and pinout. That would have the advantage that it would work on a standard breadboard.

The other thing I've been considering is soldering 30 AWG wires to the pads on the T4 and routing them directly to pins on the breakout. I'm not sure how difficult that would be. I use the 30 gauge wire for my prototyping boards (I'm an old wire-wrap guy!)
 
DerekR said:
Michael,
I'm very frustrated. I want/need to get going with using the T4 in real tasks, but unless I can get at all those pins, I'm stuck. I started to build a prototyping board this morning using the loglow beta breakout, but the thought that because that there is no assurance that the footprint will not change, I now question whether it is wise to go ahead.

I was going to wait for my .8mm versions of my modded blackketter's board to arrive before ordering thicker ones, but now I think I'll just get them into the pipeline at OSH right away.

I've also been toying with the idea of taking the castellated cut-outs of blackketter and creating a new board with loglow's DIP footprint and pinout. That would have the advantage that it would work on a standard breadboard.

The other thing I've been considering is soldering 30 AWG wires to the pads on the T4 and routing them directly to pins on the breakout. I'm not sure how difficult that would be. I use the 30 gauge wire for my prototyping boards (I'm an old wire-wrap guy!)
Click to expand...

I am poor in soldering, and just wrecked a purple Teensy 4.0 trying to cut the VUSB->VIN trace (fortunately, I had ordered another purple Teensy and I have a green one also) before attaching the blackketter board. I've soldered 22AWG stranded wire to the pads for the back pins, and twice I've had wires come off. In addition, I temporarily prevented the Teensy from booting with an errant solder bridge, and in removing the solder, I destroyed one of the pads (fortunately not a pin I expect to need).

I was thinking of using a surface mount header such as:

and then soldering the wires to that (or possibly using a breakout board).

There is the pogo pin method Paul used in the beta breakout boards, but unfortunately, he didn't attach the pins I wanted (most notably SPI2 but also I2S2), and the board is way to big to use in costumes:

I really need to learn how to design my own PCB.

Note, as I see it there are 3 parts to bring out, and different people want to bring out different things:
  • There are the back 10 pins (24-33). These are 0.1" (2.54mm) pitch;
  • There is the USB host D+/D- pins; (and)
  • There are the 8 pins for the SD card or 3rd SPI bus at 1mm, and perhaps the hardest for people like me to solder. Looking at the blackketter board, I can see the possibility of unintentional solder bridges.
[/list]
 
Looking for something good too - @loglow board update underway from misrouting and maybe other refinement for best/better assembly. The blackketter board looks good - though wondered about those tiny SD cuts looking like the ones that arrived:(

MichaelMeissner said:
… just wrecked a purple Teensy 4.0 trying to cut the VUSB->VIN trace (fortunately, I had ordered another purple Teensy and I have a green one also) before attaching the blackketter board. I've soldered 22AWG stranded wire to the pads for the back pins, and twice I've had wires come off. In addition, I temporarily prevented the Teensy from booting with an errant solder bridge, and in removing the solder, I destroyed one of the pads (fortunately not a pin I expect to need).
...
Click to expand...

Ouch ... Wondering how trace cut wrecked the T4? Cut too deep or slip of the knife took out something else?
 
As I have slightly different requirements (I need some mounting holes and connector to Audio and storage board), I make my own breakout board.
For this I plan to use the blackketter approach but removed the cut-out at the 5 end pins (cannot see any reason for them)
I also changed the 0.8 mm pins (to be cut-out) into rounded pads 2 x 0.75 mm hoping there is more copper on board to survive the cut.
The larger pins that are for T4.0 bottom pads are also made a little bit thicker (1.75 mm size)
 
WMXZ said:
As I have slightly different requirements (I need some mounting holes and connector to Audio and storage board), I make my own breakout board.
For this I plan to use the blackketter approach but removed the cut-out at the 5 end pins (cannot see any reason for them)
I also changed the 0.8 mm pins (to be cut-out) into rounded pads 2 x 0.75 mm hoping there is more copper on board to survive the cut.
The larger pins that are for T4.0 bottom pads are also made a little bit thicker (1.75 mm size)
Click to expand...

The reason for the end cuts is to bring out the three buttons from the end row to the side pins:
  • on/off
  • program
  • Vbat

Now, if you are doing your own PCB, you could just as easily have mounting holes for those.
 
Hi guys - How did the pogo pins on Paul's beta breakouts work out - were they reliable? While playing around in KiCad this afternoon I started wondering if that might be the way to go???
 
DerekR said:
Hi guys - How did the pogo pins on Paul's beta breakouts work out - were they reliable? While playing around in KiCad this afternoon I started wondering if that might be the way to go???
Click to expand...

For me. the wrong pins were brought out in the shield I got (pins 30, 31), so I never used the pogo pins for the underneath 10 pads. I did use them for the on/off button and they seemed to work, but the on/off button has a hole the pogo pin fits in, so it aligns better.

Paul had this to say in the directions for the breakout shield:
Before soldering any other through-hole parts, solder the pogo pins. Getting these 12.5 mm tall pins aligned at a right angle to the PCB is tricky. The beta boards were held in a Stick Vise to keep the board flat with the table facing top side up and the surface covered with extra liquid flux, then the pins inserted and heated from their side while a small amount of solder was applied. They take quite some time to cool down. Use caution to avoid burned fingers!
Click to expand...
 
DerekR said:
Hi guys - How did the pogo pins on Paul's beta breakouts work out - were they reliable? While playing around in KiCad this afternoon I started wondering if that might be the way to go???
Click to expand...

POGO worked in a fashion - generally good. Alignment is important … and too many of those little springs can put enough upward pressure to give unreliable connections.

First 1062 Beta board had FULL POGO including tiny close ones for the SDIO - Paul added support plates to center and hold them.

Later boards had some sparse POGO pins for the 2x5 pins - I got some extra pins to fill the blank holes - placed them and pressed them in place with T4 and bottom soldered to work.

Paul posted to OSH the later breakout that combines POGO and the sdio cable. As built that works.
 
Next questions: 1: What do think of Dan's (@loglow) SMD 2x5 header to connect to the lower board vs the castellated cut-out? Personally, having built many T3.6 breakouts from loglow, I like them.
2: How did Paul's flex cable socket on the sdio end T4 work out in the beta? The problem I had today was that the digikey Amphenol part that Paul specified in his BOM is now declared obsolete at digikey :( The Wurth ones that they have are all right angle mounting. Digikey does have the FFC cables. I haven't searched around for other vendors yet,

My other problem is that I learned today that I hate KiCad with a passion! Give me the old Eagle I used to know and love...

I must say I really hope @loglow is able to make some headway with the redesign. I'll gladly stop my feeble attempts.
 
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Looks very good, and I'd certainly like to try it! I note you are using 0.8mm board thickness. Several of us have tried OSHpark with @blackketter's design with 0.8mm and found that routing of the castellated edges tore off the copper, rendering the boards useless. In addition they did not rout out some cut-outs... I'd be concerned about the same thing happening with your board.

You mention that you had success with boards from another PCB house. Would you be agreeable to letting us know who that is, and even provide Gerbers etc so that we might order directly from them instead of OSHpark?
 
DerekR said:
Looks very good, and I'd certainly like to try it! I note you are using 0.8mm board thickness. Several of us have tried OSHpark with @blackketter's design with 0.8mm and found that routing of the castellated edges tore off the copper, rendering the boards useless. In addition they did not rout out some cut-outs... I'd be concerned about the same thing happening with your board.

You mention that you had success with boards from another PCB house. Would you be agreeable to letting us know who that is, and even provide Gerbers etc so that we might order directly from them instead of OSHpark?
Click to expand...

Thanks DerekR,
The 1.0mm pitch castellated holes were all good for my a 0.8mm PCB made by Oshpark. In the future as long as they route out all cut off holes, their PCB will be usable. My board is unusable because they did not route out cut-out holes that I specified, not related to the 1.0mm pitch castellated holes.

With small holes, there is not much copper left after routing. To make board thicker or make hole size larger will add more copper. I like the thinner board because I can use regular headers. To make holes bigger, I need to put holes in a zig zag pattern.

The other PCB house that I used is pcbway. I think that any PCB house can do it as long as the hole size meets their spec. I have 7 boards left, if you would like to try it, I can give you one for free if you cover the $3 shipping to a US address. In this way you can get your project going faster, Oshpark will take 2 weeks to deliver. Are you in US or another country?

The Gerber files of the FRDM4236 can be downloaded from Oshpark.
 
That would be fantastic, thank you very much. Yes, I'm in the USA (Mass). I'll PM you with the details.

I've been getting quite frustrated lately because I've tested most of my code on the T4 in bits and pieces but I need to build a complete new prototyping system for the T4 with as many pins exposed as I possible for integration of all the components. I don't need sd card or USB Host, just GPIO pins I didn't want to start building hardware until I had a breakout that worked.

Thanks again,
Derek
 
blackketter said:
This is great, nice work! Did you consider access to the USB pins? I wonder if there's a way to add a USB port here...
Click to expand...

Thanks blackketter,
I did not think about the USB port. If a USB port needs to be made, I guess that it can be made by a small separate PCB with a female header to provide USB signals: 5V, D-,D+,G,G, like the one on the Teensy 3.5.
 
FRDM4236 said:
I made a third Teensy 4.0 breakout board with Teensy 3.6 footprint. it worked as a 3.6.**
You can order it at Oshpark, but make sure to ask them not to miss any castellated holes.
https://oshpark.com/shared_projects/CrfX6z5v**

The details and assembling instructions are available at: *http://www.trainer4edu.com/edubase_teensy/frdm_4236.html
Click to expand...

Would it be possible to list the actual products for the ferrite beads, capacitors, and resistors? I'm not up on the numbering scheme used for surface mount components, and there are just so many different options at places like digikey, that I would prefer not to make an order and then discover they weren't the right size. For example, looking at the ferrite beads, there are different sizes 0402 and 0805, but I didn't see anything that was 0402-0805.
 
MichaelMeissner said:
but I didn't see anything that was 0402-0805.
Click to expand...

I'm pretty sure this means any size ranging from 0402 to 0805, this includes 0603.
Go for the largest size(0805 imperial). For those with a slight masochistic tendency go for 0402.

If I'm not mistaken, the smallest components on the bottom side of Teensy4 are 0402.
 
neurofun said:
I'm pretty sure this means any size ranging from 0402 to 0805, this includes 0603.
Go for the largest size(0805 imperial). For those with a slight masochistic tendency go for 0402.

If I'm not mistaken, the smallest components on the bottom side of Teensy4 are 0402.
Click to expand...

Thanks Palmerr for your Eagle lib
************************************************

neurofun is right, any size ranging from 0402 to 0805.
If you happen to have one size, but no other sizes, you still can make it. The value is not critical for decoupling, 20% tolerance is fine. The parts are all regular, not special parts. Any types are OK.

The Ferrite Bead is LI0805H151R or LI0805H121R, either one is fine. I don't know what the difference they will make, I have no way to find it out. It's just something many circuits used it. If you don't have it, just short it with a wire. It will still work. You can get it from Digikey or Mouser, Mouser's price is cheaper.

I have 3 blank pcbs now. I realized that it's inconvenient to order parts and pay shipping charges by yourself, I can make 3 today to help some forum members who need it more urgently.

$4 for assembled board plus $3 shipping. Will mail it out to a US address only tomorrow, so you can get it next Monday or Tuesday. You can email me at trainer4edu@gmail.com to place your order. Only 3 boards are available. First come first served.
 
I'll also have 3 spares of Paul's T4 BoB design in a week or two - I ordered a run last week from China.
 
FRDM4236 said:
I made a third Teensy 4.0 breakout board with Teensy 3.6 footprint. it worked as a 3.6.**
You can order it at Oshpark, but make sure to ask them not to miss any castellated holes.
https://oshpark.com/shared_projects/CrfX6z5v

The details and assembling instructions are available at: *http://www.trainer4edu.com/edubase_teensy/frdm_4236.html
Click to expand...

In preparation for getting my board today, I looked at the pin assignments of the board. I noticed that where the 2 DAT pins (A22/A21) are in the 3.5/3.6 are not used. If you ever decide to respin the board, you might want to think about putting the on/off and program buttons there for people that want to incorporate the Teensy in a larger prototype board, and connect those pins to buttons elsewhere on the larger breakout.

Alternatively, if you worry about Teensy 3.5/3.6 compatibility, given those are analog input/output pins on the 3.5/3.6, it may make sense to move pins 24/25 there, and put on/off and program where 24/25 used to be. That way, you could still do analogRead and analogWrite on something connected to those two pins (obviously, it wouldn't be a DAC like the 3.5/3.6 and you would have to use #ifdef).

The other candidate for those two pins would be D+/D- for the USB host facility. But that probably is better near the front of the board separately, to keep the wires as short as possible. I suspect if you add USB host, it may add to the issues in getting the fab to properly castlellate the board.
 
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