Teensy 3.2 future availability and Teensy 4 compatibility

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bboyes

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We designed Teensy 3.2 into a commercial product sold nationwide by our customer. This product is doing well - over 1000 are in the field and customers like it. It has an anticipated life of 10 years more or less, typical for so-called embedded systems. In the design we considered part lifetime as much as possible, but it's always a production headache even when you make best efforts.

Just moments ago I learned Teensy 3.2 is 'discontinued' at OSHPark. We have a run of 260 commercial products in process now and need 220 more Teensy 3.2 ASAP to complete it. So far I have no reply from OSHPark if I can get 220 from them, nor did they give any heads up about the discontinuation. In addition to the current work in process we have another run of 260 scheduled later this year.

So: what is the availability of Teensy 3.2 from PJRC for the next few years?

I just learned of Teensy 4 (paying work tends to take priority over all else; it can be hard to keep up with all the news on many fronts) but have not had time to look into it. It is stated to be "mostly compatible" with 3.2. I need to learn what the "not compatible" areas are. I'll order a couple and the breakout board today. We will also look at the idea of a castellated breakout for it, something like this: https://oshpark.com/shared_projects/tYujJtts which would let us simplify mounting it to our board, vs the pin and socket board we use now: https://oshpark.com/shared_projects/HGzzmZbK. We use the breakout because we need access to bottom side castellated contacts for RESET, SCL1 and SDA1 (P29, P30), RX2 and TX2 (P26, P31). We use so many of the topside pins that we could not use those top-side alternate mappings for the second I2C and UART. Plus we need access to the hardware RESET line so that our entire system can have a central voltage monitor and hardware reset control.

Any advice on moving forward?

Moving from T3.2 to T4: is there a schematic? The pinout card doesn't seem to show RESET made available (critical for us). And it looks like we'd have to change to UART 6 or 7 and I2C 2 since those are what's available on the backside (we could manage that). So T4 no RESET might not be a fit. (T3.5/6 has RESET on the interior through-hole pads).

A module (3.5/6 or 4) with all the interior pins brought out to exterior-edge castellations for easy production soldering onto a larger board would be ideal for us.

Revving our system control board and any impacts on firmware and production issues (test fixtures and tooling) make this something we have to consider carefully. Then there is the question of selling the idea to our customer and funding the changes. I'm posting to the forum since there may be others in the same boat who might have similar interests.
 
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paul would have to reply, but I dont think the 3.2 is going to be discontinued at this time. I could be wrong though. paul?
 
We designed Teensy 3.2 into a commercial product sold nationwide by our customer. This product is doing well - over 1000 are in the field and customers like it. It has an anticipated life of 10 years more or less, typical for so-called embedded systems. In the design we considered part lifetime as much as possible, but it's always a production headache even when you make best efforts.

Just moments ago I learned Teensy 3.2 is 'discontinued' at OSHPark. We have a run of 260 commercial products in process now and need 220 more Teensy 3.2 ASAP to complete it. So far I have no reply from OSHPark if I can get 220 from them, nor did they give any heads up about the discontinuation. In addition to the current work in process we have another run of 260 scheduled later this year.

So: what is the availability of Teensy 3.2 from PJRC for the next few years?
Paul has to be the one to answer this. But I suspect it may have to do with the availability of the chipset used in the Teensy 3.2. If NXP stops selling that chip, Paul will have to stop selling Teensy 3.2s once his stock of chips runs out. But given he is still selling Teensy 2.0/2.0++, I have to imagine it will be a long pipeline before it stops being available (assuming chip availability).

Note, Paul has said that the end is in sight for the 2.0, but he hasn't announced an official EOL date.

I just learned of Teensy 4 (paying work tends to take priority over all else; it can be hard to keep up with all the news on many fronts) but have not had time to look into it. It is stated to be "mostly compatible" with 3.2. I need to learn what the "not compatible" areas are. I'll order a couple and the breakout board today. We will also look at the idea of a castellated breakout for it, something like this: https://oshpark.com/shared_projects/tYujJtts which would let us simplify mounting it to our board, vs the pin and socket board we use now: https://oshpark.com/shared_projects/HGzzmZbK. We use the breakout because we need access to bottom side castellated contacts for RESET, SCL1 and SDA1 (P29, P30), RX2 and TX2 (P26, P31). We use so many of the topside pins that we could not use those top-side alternate mappings for the second I2C and UART. Plus we need access to the hardware RESET line so that our entire system can have a central voltage monitor and hardware reset control.

Any advice on moving forward? Moving from T3.2 to T4? Any plans for a T4 with all the interior pins brought out to exterior-edge castellations for easy production soldering onto a larger board?

Revving our system control board and any impacts on firmware and production issues (test fixtures and tooling) make this something we have to consider carefully. Then there is the question of selling the idea to our customer and funding the changes. I'm posting to the forum since there may be others in the same boat who might have similar interests.
I suspect you will need a completely different PCB, since a lot of what you used changed. If you only use Serial1, I2C1 on default pins, SPI1 on default pins, only use analog pins A0-A9, do not use touch pins or the DAC, then things are simpler. Here is a reply I wrote summarizing the differences that I knew of, and the google doc listed in that replay that tries to summarize the pin differences:


Here is a thread about designs for a breakout board:
 
PJRC indicates the T3.2 board is in stock for now: https://www.pjrc.com/store/teensy32.html and the CPU it uses is in stock at the large distributors. I would expect Paul to have many months, if not years of visibility into EOL plans for the CPU, although there are always temporary part shortages possible.

Note by the way unlike some other boards, Teensy 4 has parts on the bottom side as well, so to solder it down flat on another PCB you would need some clearance cutouts.
 
That spreadsheet is helpful, thanks. Row 112, cell BX, "other" pins area shows no RESET on T3.2 but RESET is there in an underside castellation: we use it bidirectionally: as input from a master reset elsewhere in our system and as output from the T3.2 watchdog to put our system into a known state and restart it. Appears no reset for T4, but what is ON/OFF?
 
That spreadsheet is helpful, thanks. Row 112, cell BX, "other" pins area shows no RESET on T3.2 but RESET is there in an underside castellation: we use it bidirectionally: as input from a master reset elsewhere in our system and as output from the T3.2 watchdog to put our system into a known state and restart it. Appears no reset for T4, but what is ON/OFF?

I don't believe there is a reset pad.

The on/off thing is new. If you connect the on/off pin to ground for around 5 seconds, the Teensy will turn itself off. It won't turn on until either the power is cycled, or the on/off pin is released, and then connected to ground for about a second. I.e. it is meant for a human switch to turn it on/off.
 
I don't believe there is a reset pad.

The on/off thing is new. If you connect the on/off pin to ground for around 5 seconds, the Teensy will turn itself off. It won't turn on until either the power is cycled, or the on/off pin is released, and then connected to ground for around a second.

To Add :

>> The Power Off state drops the 3.3V regulator power as well.

>> Also if there is VBat power on the T4 - the OFF state will survive power removal. It will still be OFF when repowered

>> Also if there is enough 3.3V current on other pins - like UART Serial device connected where the idle state is 3V+ it will feed the low power portion of the T4 like VBat does and that will retain the Power OFF state even when power is removed.

>> Also with that VBat or enough pins fed 3.3V :: The power button does Function when the T4 is NOT POWERED. That is the ON/OFF state will change when pin grounded even if unpowered when VBay low power section is powered.


And indeed the T4 does not present a RESET pin, but OFF then ON does restart the Teensy 4 as if reset.
 
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