Any Chance of a Teensy ++ 3.1?

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I was wondering if you had any plans to make an expanded pin-count version of the Teensy 3.1, in the same vein as the Teensy++ 2.0.

I've got a project that's been back-burnered for a while that'll involve replacing a DIP-40 chip in an existing device with something more modern and programmable. (Specifically, replacing the controller in an old IBM Model-M keyboard)

The Teensy++ 2.0 is near-ideal for the application, but the MK20DX256 on the 3.1 is so much sexier.
Over at, Tall Dog LLC has two break-out boards that give you access to the pins under the Teensy 3.0 (and now 3.1):

I have both, but I need to improve my soldering skills before I tackle these. The mini-breakout is the same width as the Teensy, and the mark 2 breakout is 0.1" wider on each side. You will need some additional headers for the mini-breakout (see the comments section for the mini-breakout).

Obviously, it would be more convenient if Paul offered a Teensy 3.1++.
Could you take into consideration additional room for the 32kHz crystal?
I was so bummed when I realized the crystals I have won't fit on the Teensy3.

All ones I have are 8.2mm or 0.320 in length and 2.9mm or .115in in diameter.
The ones on the DS1307 i2c modules I have also use that same sized crystal.
Maybe that size is more common than the 6mm citizen crystal needed for Teensy3?

--- bill
I've actually been working on Teensy++ 3.X. It's too early to discuss the details, but I can assure you, I am indeed working on a Teensy++ 3.1 and I'm pretty sure you'll like it. ;)

I'm aware that Paul will not be able to comment, but here is my speculation. Paul has said before that he is working on a new product, and is unable to discuss the details because it uses an unreleased chip (so presumably, it is under NDA). The chip used in the Teensy 3.1`is 72MHz and has two ADCs; there was an announcement of K20 72Mhz chips with 2 ADC on Nov 15, 2011 with full production scheduled for Q2 2012. Thus, the Teensy 3.1 is not the new upcoming very powerful product with an as yet unreleased chip. (Its a very nice mid-life upgrade for Teensy 3.0, to be sure).
Just my speculation of course.
I would really LOVE to see accessible JTAG Pins.

On the other hand, I was thinking about other debug options, maybe running the OneWire protocol (or something similar) on the PROG line to send commands to the Mini54 that would then forward them to the JTAG port on the Kinetis. This would be a simple firmware-update. Actually, a SECOND Teensy could be used to translate JTAG debug commands from GDB into this OneWire protocol... Anyone knows if the speed of 15.4 kbit/s (standard mode) or 125 kbit/s (overdrive mode) of OneWire imposes any serious restriction for JTAG debugging?

Paul, I know that you consider the Mini54 firmware proprietary, but do you see a chance for this?
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I've actually been working on Teensy++ 3.X. It's too early to discuss the details, but I can assure you, I am indeed working on a Teensy++ 3.1 and I'm pretty sure you'll like it. ;)

Any update of when we could expect the Teensy++ 3.X??? I'm anxiously waiting another great product (and not needing a breakout board to conveniently access all the pins) :)

Any update of when we could expect the Teensy++ 3.X??? I'm anxiously waiting another great product (and not needing a breakout board to conveniently access all the pins) :)


I second this sentiment! This has been such a great product it's hard not to be greedy for more developments ;)
29$ would seem to be a logical price given the teensy2++ is 24$ and the Teensy 3 is 19$.

This seems very reasonable, I've gone through about 10 Teensy 2++ and Teensy 3.1 depending on the application, for a few bucks more I'd just buy the 3.x++ 'just in case'
$29 if there's a second SPI, $24 otherwise ;)

Really depends on what it can do, but I'm pretty sure it's going to be a great thing.
It very much depends on what extra it offers.

Looking at why I use Teensy++ 2.0 in a project, Teensy++ 2.0 costs 50% more than Teensy 2.0 and gives
* 4x the flash
* ~3x sram
* 4x eeprom
* ~2x digital IO pins including 3 complete 8-bit port sets (A, C, F) while leaving I2C and SPI free (or 5 ports, including B and D).

In my project that let me dispense with port expanders and manipulate lots of IO fast while having lots of room for lookup tables. So it was much better than Teensy 2.0 or Teensy 3.x in that regard.

Teensy 3.1 costs about $20. So about $30 would seem reasonable and follow that precedent; depending on what ++ 3.1 would let you do that 3.1 does not. Some desirable things from my point of view:

* more pins conveniently available
* some contiguous ports to allow bunches of pins to be read or set together
* floating point
* better ADC (higher ENOB, more simultaneous channels/comparators/PGA)
* more and/or better DAC
* twin I2S to controll two Audio boards
* USB host capability

If the price tends towards only 25% more than 3.1 then it would sell like hot cakes. If it tends towards 75% more than 3.1 than it faces (possibly unfair) comparison with larger, faster, but connectivity-challenged linux-based boards like Beaglebone Black at $55.

But it really all depends on what extra it can do over 3.1.
I just want more pins that can be accessed like AVR PORTS and correctly sequenced as the sexy Teensy ++ 2.

I think I'll make a breakout for Teensy 3.1 like the tall-dog one. Good idea!
Maybe it's time to share (or "leak") a few Teensy++ 3.x details, even though the product is still pretty much in the planning phase.

Here are 5 things that are absolutely certain about Teensy++ 3.x:

  1. ARM Cortex-M4F (Floating Point Unit)
  2. Under $30
  3. More I/O pins
  4. More serial & SPI ports
  5. More memory

I'm leaning towards a 48 pin form factor, with an extra 3.3V & GND pair. I'm still debating whether AREF should be brought to the outside breadboard-friendly edges. Likewise, I'm considering whether the to bring out some analog-only pins (like A10 & A11 on Teensy 3.1), which offer perhaps lower noise and differential analog signal input, but they can't be used for digital. Total number of digital pin on the outside edge could range from 35 to 40 or even 42, depending on whether some pins are extra power and analog only stuff.

I'll very likely put a Micro SD card socket on the end of the board. The "large" applications where you use such a powerful microcontroller often need storage, so that seems like a good use of the extra space (from making the board longer). But perhaps that extra room could be more useful as lots of through-hole pads for extra digital signals? In theory, you could always add an adaptor for storage, but my gut feeling is in practice many applications use storage media.

Also, while I'm spilling rumors, PJRC is working on a lower cost Teensy 3.x based on an ARM Cortex-M0+ chip. It will feature similar I/O and peripherals as Teensy 3.1 (except the bottom pins), with less memory and a slower processor, but a retail price in the $12 to $14 range.

We don't have any hard deadlines for these new products. I can tell you I'm very committed to working on the software support side, which often comes at the expense of working on making new hardware, so it's quite possible both of these may slip for quite some time.
Sounds excellent. Can you tell us how much memory you're predicting for the Cortex-M4F chip? If so, how much?
Without compromising PJRC's protection from counterfeits, some of us really need a way to do code in flash upgrades remotely, e.g., via a wired/wireless network connecting to an unattended device that may by quite distant.
Preferred way is to have an SD card or better, a low cost flash chip which can also be used for data logging. Less preferred but do-able is a custom bootloader in a never-overwritten sector of flash that does an in-place down-load and rewrite flash, without bulk storage. I've done this, using a CRC check so that a disrupted download will case the bootloader to start again. Worked well.

The USB-only precludes M2M type applications.

Here's an example of a board with a very low cost flash chip for bulk storage. (scroll down to schematic)
That chip is 16MB of fast bulk flash, via SPI. Cost $1.40 @ 100ea

PS: a board like that with a Cortex Mx instead of the too-small RAM mega328 would be a good seller, with Teensyduino libraries. Based on quantities of Anarduino's board sales, mostly for M2M apps.

EDIT: added flash chip info above
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Unfortunately, you probably are constrained to having the pins in the same location as the Teensy 3.x, but it would be nice if Vin and Vusb were adjacent to each other, so we could use a standard 2 pin jumper. However, that is low on the list of priorities.
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