Teensy 4.0 Breakout Kit

Sounds good Dan, looking forward to the next Beta to see how the feedback leads to any changes for clean assembly.


I made some steps toward a menu for the expanded dynamic runtime "KurtE + 'xx=' multi test" to ring out pins during assembly steps.
 
so dan, any news? good or bad dont matter. :) can't wait to try the updated version. I have somewhat horrible vision and I didnt have a lot of issues soldering things. even that tiny cap and power chip. :) dont have the proper no clean flux, but some rubbing alcohol and a tooth brush just for this and it cleaned right up.
 
@loglow - Hi Dan. I haven't been very active on the thread because the breakout has continued to work well (except for pins 35&36). I have it running 24/7 on all sorts of software and peripheral chips and boards (music, SDR, scientific instruments). No problems, within the constraints of my tests, but I haven't tried USB because I don't trust my flex cable with the standard size headers.

Do you expect to change the footprint on the next go-around? I'd love to start wiring a general prototyping board, and I'll get started as soon as I know what your plans are...
Derek
 
Question about the @KurtE pinsheet that @loglow turned into the nice Legal Print color table:

The ALT5 Column references the GPIO[1,2,3,4] names of the pins.

When the T_4.0's 1062 is powered up in startup.c the change is made to " // Use fast GPIO6, GPIO7, GPIO8, GPIO9 "

Question: Should those column references be changed to reflect the GPIO[6,7,8,9] names of the pins?
* Once this sheet is validated it seems such a good reference sheet that PJRC could post it with the T4 Card and/or other REF pages.
** One other suggestion - the lower right 'gray' corner might be a good place to put a "COLOR CODE to FUNCTION NAME" key for the REF colors as it appears on the TallDog pinout card.

ALSO: Today I got a USB to wired Ethernet adapter for another thread - I first ran that downloaded library WIP and plugged that USB adapter into this TallDog breakout board and it ran well. I even unplugged the USB adapter off then back on and it resumed the IP test it does.
 
Question about the @KurtE pinsheet that @loglow turned into the nice Legal Print color table:

The ALT5 Column references the GPIO[1,2,3,4] names of the pins.

When the T_4.0's 1062 is powered up in startup.c the change is made to " // Use fast GPIO6, GPIO7, GPIO8, GPIO9 "

Interesting question: I sort of asked up on other thread, if there is more documentation, as I see very little describing GPIO6-9, other than there are some comments in code and a few places in manual that describe some registers, clocks, ...

But so far my spreadsheet simply reflects that actual page data in manual. Like for our Pin 0, if you look at page 473:

Code:
MUX Mode Select Field.
Select one of iomux modes to be used for pad: GPIO_AD_B0_03.
000 ALT0 — Select mux mode: ALT0 mux port: FLEXCAN2_RX of instance: flexcan2
001 ALT1 — Select mux mode: ALT1 mux port: XBAR1_INOUT17 of instance: xbar1
010 ALT2 — Select mux mode: ALT2 mux port: LPUART6_RX of instance: lpuart6
011 ALT3 — Select mux mode: ALT3 mux port: USB_OTG1_OC of instance: usb
100 ALT4 — Select mux mode: ALT4 mux port: FLEXPWM1_PWMX01 of instance: flexpwm1
101 ALT5 — Select mux mode: ALT5 mux port: [COLOR="#B22222"]GPIO1_IO03 of instance: gpio1[/COLOR]
110 ALT6 — Select mux mode: ALT6 mux port: REF_CLK_24M of instance: anatop
111 ALT7 — Select mux mode: ALT7 mux port: LPSPI3_PCS0 of instance: lpspi3

What is maybe sort of interesting to look at is what does this do for pin interrupt code? Comment in wondering, not sure how handled.
For example: GPIO1 has IRQs (72-81), GPIO2 has (82, 83), GPIO3 (84-85), GPIO4 (86,87), GPI5(88,89)

GPIO6-9 has only IRQ 157

So I believe to process any IRQ handled by any IO pin, we have to scan that status of 31*4 status values to see what happened.

Wonder if maybe at times fast IO is not necessary fast?
 
Hi all, I’m sorry for my silence this past week, I’ve been extraordinarily busy. I’ll try to catch up with everyone on here tonight.
 
Yes, do it when you have time to make any needed changes come out as you can live with.

I have been using the original pinned T4 for USB to wired Ethernet on other thread and it works fine with or without going through powered hub. Also tested on the MSC thread's code to access USB HDD's no problem - though a powered hub required then.

I got some plastic M2 sized stand off's and they work well.

Since I wrongly placed the first female short header on the bottom - then the second - my battery is trapped - so if you find a battery holder on the same spacing to drop in fit I'd like an extra to retrofit the original to have a replaceable battery.
 
Hi everyone,

I haven't been nearly as responsive here as I'd like to be, since I've had a lot going on over the last several weeks, some of which was unexpected.

I'll be on a train with Wi-Fi (hopefully) for at least 4 hours tomorrow, so I hope to catch up on everything in this thread during that time!

In the meantime, here's a new board revision that a) corrects the order of the SD pins and b) replaces the battery holder footprint for a top-loading style holder.

Teensy_4_0_Breakout_T.jpg

Teensy_4_0_Breakout_B.jpg

All the best,
Dan
 
Hi Dan, Welcome back:D I presume you are aware of the two other break-outs that have been released over the past few weeks? Both use castellated cutouts to contact all of the under-board pads. A few of us have tried both successfully - for example, I did a quickie review of them here.

That said, I don't want to discourage you in any way. You have a great reputation for your well designed T3.x boards, and I continue to use your T4 beta board on a daily basis. You have the (very important) advantage of an established marketing platform, and providing one-stop shopping for a complete kit.
 
Here's an update!

I got the first batch of test boards back. The flex cables look good, and seem to work fine, both in terms of direct soldering, or when used with a connector socket. They are 0.26 mm thick, which was the closest to 0.3 mm (the recommended thickness for the sockets) that I could reasonably make them. I didn't want to use stiffeners on either end since I wanted them to be able to be soldered directly as well.

The breakout boards have some mistakes. The component numbers (U1, C1, C2, etc.) got messed up on most of the boards when I panelized them, but that's an easy fix. The big issue is that I got the SD socket backwards. Since I haven't used these very narrow sockets before, I apparently didn't assume the correct orientation. Whoops. I've re-positioned and re-routed this component. It's a bit tight, but I still managed to stick to >6 mil traces/spacing. New revision below:

View attachment 17404
this version of the a2 board marked 2019-8-29 has the correct pinout for the sd card as far as I can tell.. for the sockets we have now
the a2 version I have. dated 2019-8-30 looks exactly like the 2019-10-19 marked a3, well not exactly but close.. they are in the same sequence.. so unless the flex flips the signals its not going to work either..
 
Good to see you back for an update Dan.

Did you give any thought to not putting GND and 3V3 through the cable but routing them on the board to feed the SD connector? Not having those two unmasked pads could lead to higher end user success in soldering.

@DerekR linked to the FRDM4236 board with castellations - one thing there that made it work well when I soldered one was not having those two pads present that allowed his staggered presentation to give some masked gaps
 
Hi there everyone! Sorry for the extended time away. My life got very busy for a moment there. I haven't forgotten about this project though, and I think we're getting very close to a release!

First of all, I've seen both Teensy 4.0 breakouts from Trainder4EDU and Dean Blackketter, and they look awesome. I think having a variety of different designs is an excellent thing. I'm still planning to move ahead with this design, because I do think it has some merits.

So, I've made a few more changes. As suggested, I reduced the pin count of the flex cable down to 8, omitting 3V3 and GND. I've also changed the design of the pads for easier soldering, and also changed the breakout-end of the flex cable, which is no longer designed to be soldered at all; it will always socket into an 8-pin flex connector. The flex cable is a bit longer too, so it should allow for use with either low-profile or standard-height sockets & headers.

I'd like to do another round of beta testing on these, so please let me know if you're interested!

Best,
Dan

Flex_Cable_T.jpg

flex_w_t4.jpg

Teensy_4_0_Breakout_B.jpg

Teensy_4_0_Breakout_T.jpg
 
Question: Should those column references be changed to reflect the GPIO[6,7,8,9] names of the pins?

I'm not sure about this change, and even less sure after reading the response by @KurtE ...

One other suggestion - the lower right 'gray' corner might be a good place to put a "COLOR CODE to FUNCTION NAME" key for the REF colors as it appears on the TallDog pinout card.

This is a great suggestion, and I've updated the chart!

PDF: View attachment Teensy 4.0 Pins.pdf

Low-res raster preview image:
Teensy 4.0 Pins Preview.jpg
 
@loglow - good to see you back with this - I'll buy another T4 and build it if you send a Beta kit - full low_pro socket set hopefully? Looking forward to it as it is a nice compact unit that gives good full utility … especially when the SD card works :)

Post#265 board/cable images look good dropping the GND/3.3V - is that going to get a REV-A4 silkscreen update?

I'm still using your first Beta board for USB and simple tests and it is working well.

The COLOR code on the expanded T4 PINS PDF is nice! That is going to be crazy with T4.1x with an added 20+ pins!
 
@loglow - If it would help, I would be happy to try another one. It may take me a few days plus to get to soldering it. Right now waiting for parts to try assembling my breakout using the FRDM (not usb) boards, which arrived a day or two ago.
 
@loglow - good to see you back with this - I'll buy another T4 and build it if you send a Beta kit - full low_pro socket set hopefully? Looking forward to it as it is a nice compact unit that gives good full utility … especially when the SD card works :)

Sounds great! Yes, I'll include a socket kit too.

Post#265 board/cable images look good dropping the GND/3.3V - is that going to get a REV-A4 silkscreen update?

Probably not, since the previous A3 revisions were never manufactured. This will stay at A3 until fab'd.

I'm still using your first Beta board for USB and simple tests and it is working well.

Great to hear!

The COLOR code on the expanded T4 PINS PDF is nice! That is going to be crazy with T4.1x with an added 20+ pins!

Thanks :D
 
@loglow - If it would help, I would be happy to try another one. It may take me a few days plus to get to soldering it. Right now waiting for parts to try assembling my breakout using the FRDM (not usb) boards, which arrived a day or two ago.

Sounds great, thanks very much!
 
@loglow, Glad to see you back and that breakout board is still on track. I would help if I could but again I don't think I could do the soldering. Can't wait for the release:)
 
@loglow - if PCB A3 wasn't made then all is good as long as we don't confuse the pics A3_p260 and A3_P265.

@KurtE - did your OSH castellations come out cut right for the FRDM board? If so I'll order and get another T4 or so.
 
@KurtE - did your OSH castellations come out cut right for the FRDM board? If so I'll order and get another T4 or so.

Not sure yet, they were sent out for fabrication on Monday, so not sure yet when they will be back. I do have one that I got direct from FRDM, which I will use to test the first of the new boards, to get an idea if anything on it works.
 
Ok!

So, in preparation for ordering a new batch, I made some more changes:

  • Replaced the TPD3S014 chip with the TPS2055A chip, as requested, which is larger and should be easier to solder.
  • Added pads for the MCP2558FD chip and associated passives, which will allow for onboard CAN bus support!
  • Lengthened the board overall from 2.6" to 2.8" to accommodate 4 additional breakout pins.
  • The 4 new pins consist of 2 new GNDs in the corners as well as CANL and CANH.
  • Moved VBUS (VB) and also moved all the USB host pins down to make room for a GND next to the CAN pins.
  • Lengthened the SD socket solder pads significantly so it should be easier to solder them.
  • Part number (TD-T40B-A3) will now be visible after the board has been assembled.
  • Date marking added to the bottom of the board.
  • Revised overall spacing and silkscreen markings.
  • Rerouted traces for all of the above changes.
Updated part reference designators:

  • C1: 100µF, 1206
  • C2: 0.1µF, 0805
  • C3: 0.1µF, 0805
  • C4: 2.2µF, 0805
  • C5: 100µF, 1206
  • R1: 120R, 0805
  • PULLUPS: 4.7K, 0805 (9x)
  • U1: MCP2558FD, SOIC-8
  • U2: TPS2055A, SOIC-8
Questions, thoughs:

  • Paul's breakout has a 22K resistor between CANL and CANH (in addition to the 120R). Is this necessary?
  • Does anyone think it'll be a problem for the CAN stuff to be (potentially permanently) underneath the Teensy like this?
  • Paul's breakout uses a 4.7µF cap near the TPS2055A but I was planning on sticking with a 2.2µF. Should this be ok?
  • The new battery holder will require the nearest 4 pins to be trimmed down as flush as possible on the bottom.
  • Any last minute changes or requests (new, or that I might have missed from earlier) before I make some of these?
Teensy_4_0_Breakout_T.jpg
Teensy_4_0_Breakout_B.jpg
 
Good job on the extension between the facing soldered pin lines for cable/SDIO - that should remove possibly the biggest problem assembly spot with crowded fine pitch soldering

With the onboard USB header - this may not be an issue worth change: The T_3.6 layout that allows a simple flexible PJRC USB_Host plug arrayed as :: 5V, DM, DP, GND, GND - where it comes between the CAN pins and T4 GND pin - this order isn't present. Leads to question: Does the TPS2055A chip control on those pins as well as routed.

Extended question [ if relevant and of any value?] - the T_3.6 has a control line routed internally on a hidden pin AFAIK that disables the TPS until USB Host is enabled? Does the TPS2055A have that feature - With an added control pin the user could wire I/O of choice to that pin? Blackketter has a pin with trace cut pad for that on the USB sidecar.
 
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