Future Teensy features & pinout

Then, a reset pin.
Definitely a +1 for an accessible reset pin. On my current T4.1 project the MCU is sandwiched between two other boards, and I don't want to solder to the bottom of the T4.1, so I'm having to use a tongue-depressor to reach into the sandwich and feel around for the switch. Very inconvenient...
 
One way to expand the number of pins available would be to provide double-density castellations along the edge. The Alorium Evo M51 does this. Every 0.1" spaced through-hole pin is brought out to a castellation at the edge. Between each of those connections is another pin, for net spacing 0.05". This provides roughly twice the pin count and makes the board surface mountable.
Similar idea, implemented on Pyboard D SF2/3/6 :
https://store.micropython.org/product/PYBD-SF2-W4F2
PYBD_SF2_W4F2_top.jpg
 
On castellation.
I understand while it could useful, but it would not be useful in presence of bottom mounted components, as done on T4.1.
Also inboard pin soldering would not be possible.
On the other side, if there are no bottom component, you always can solder the board directly onto another board using the pin-through.
I even waist my headers (used upside down) to connect two boards without space and remove the plastics.
OK, one has to place 2 solder points.
 
Hello!

Some wishes:
- power protection circuit, that disables the USB power line when external (VIN 5V) power where applied
- 2.54mm ethernet (and USB host?) headers
- debugging with breakpionts
- reset button and pin
 
Most, if not all of this, is available already. NXP supports its iMX.RT chips with the MCUExpresso package which includes a SDK that is based on the Arm CMSIS. They also offer FreeRTOS, iwIP, FATfs, and other middleware stacks.

NXP provides example projects for gcc and cmake. If you prefer an IDE you can use eclipse or PlatformIO, or (paid) Keil or IAR.

Info here:
https://www.nxp.com/software:employee monitoring

Thanks for the link! Drivers for communication peripherals with include high-level transactional APIs is a very good thing!
 
I vote for something like this (to get all pins + extra GND:s)
teensy51.jpg
as homemade pcb:s with 0.15mm tracks is possible (to fit two tracks between each pin)
twoTracksFit.jpg
the ic above is a pic32mx360 0.4mm spacing (I have never used it:p)
also it's still possible to easly solder wires on three rows using perfboard.

that would make it possible to connect high pin count displays/buttons/pots
without sacrificing any valuable peripherals pins.

I would also vote for placing all essential peripherals pins
on one side (if possible) to make it even easier while prototyping.


to use the outer pins either it can be mounted on a pcb (perfboard/custom)
or double row angle headers can be used for height efficient prototyping.

myTeensy40board.jpg
the DAC is a PT8211
and I'm using a MAX6818E for easy debouncing of the pedal buttons.

I don't believe in either MicroMod or high density headers,
as that makes it harder while prototyping
0.05" is not that prototype friendly either
the ESP32 modules use that.

I prefer 0.1" for all prototyping work.

A real reset pin should be nice.
as the POR_B is controlled by the bootloader chip
it's the bootloader that needs to take care of the reset pin
(that is also good as it needs some debouncing which can be taken care of in the bootloader chip)

the USB host pins should be aligned with the other pins so that it can easly be used with a header connector too
(specially in perfboard designs)
but it would make it much easier in custom pcb:s as well.

the ethernet pins is still usable as they use a low height flat cable connector.


That is my thoughts.
 
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It seemed to me that the 2.54 connector is more versatile - it can be soldered on top and used with a flat cable (as it is now), or it can be soldered on the bottom, then the entire module can be connected to the motherboard, on which the ethernet connector is soldered.

Or am I missing something?
 
@Allineer
2.54 connector?
the ethernet connector is 2.0mm
but all other pins are 2.54mm(0.1")
(I usually use the metric system)


+features
One extra feature that would be better than many IO
is to have 64MB SDRAM like Daisy have,
That would mean that we can have nice effects,
and also make it possible to load and use big wavetables from a SD-card.

maybe there could be two versions?
1. with many IO and no SDRAM
2. with SDRAM and not many IO

about the dual core
I think there is no need for any RTOS
as it would be more fun to learn about
atomic manipulations and shared memory
off course there could be implemented libs
for making that easier, but RTOS is not needed.

One core can be used for the sound stream (specially for very big projects)
and the other could take care of all the (user interface)/(loading saving files to/from sd-card)/(other comms.)
 
about the dual core
I think there is no need for any RTOS
as it would be more fun to learn about
atomic manipulations and shared memory
off course there could be implemented libs
for making that easier, but RTOS is not needed.

agree completely.
Fun with Teensy is as it is now
All compiled from source code with full control of features
 
@Allineer
maybe there could be two versions?
1. with many IO and no SDRAM
2. with SDRAM and not many IO

It would be easily possible to just have one version with a TSSOP footprint for a 16-bit SDRAM (or preferably two footprints to utilize the external 32bit wide memory bus) and still have a huge number of I/O pins available. The SDRAM footprint could be unpopulated, just like the SPI flash and SPI PSRAM footprints are on the T4.1. Separate versions would only complicate things in designing.

A quick note about castellations:
1) They are only useful on boards that have no bottom side components. The idea behind the castellations is to allow surface mounting the board to another board.
2) Castallated holes tend to add a fair amount at most (if not all) PCB manufacturers. Extra expenses in production must be passed on to the consumer, and I, for one, don't care to pay for something is not useful.
 
A quick note about castellations:
1) They are only useful on boards that have no bottom side components. The idea behind the castellations is to allow surface mounting the board to another board.
2) Castallated holes tend to add a fair amount at most (if not all) PCB manufacturers. Extra expenses in production must be passed on to the consumer, and I, for one, don't care to pay for something is not useful.
The topic of castellated pins has come up a couple times before in this thread. One major challenge is the decoupling capacitors on the bottom of the PCB. These would require a cut out if one were trying to solder to a baseboard.

I saw this announcement for an i.MX 8M Plus application processor board. It is a QFN style 29 mm square system-on-module (SOM). It has castellated pins at its periphery and what look like ground or power pads on the bottom. It is designed to be soldered to a motherboard. There are no components on the bottom side, and they specifically note that no cutouts are required. I don't know how they avoided the need for decoupling caps below the BGA but it's worth looking into as an option for the I.MX RT1170 Teensy. The link to the announcement is here https://www.karo-electronics.com/qsxp
 
The topic of castellated pins has come up a couple times before in this thread. One major challenge is the decoupling capacitors on the bottom of the PCB. These would require a cut out if one were trying to solder to a baseboard.

I saw this announcement for an i.MX 8M Plus application processor board. It is a QFN style 29 mm square system-on-module (SOM). It has castellated pins at its periphery and what look like ground or power pads on the bottom. It is designed to be soldered to a motherboard. There are no components on the bottom side, and they specifically note that no cutouts are required. I don't know how they avoided the need for decoupling caps below the BGA but it's worth looking into as an option for the I.MX RT1170 Teensy. The link to the announcement is here https://www.karo-electronics.com/qsxp

I like the look of the KaRo compute modules. Something similar based on the 1170 would be pretty interesting to me. The one issue that gives me pause is the exposed ground plane that prevents top layer routing under the module. It might not be a big deal but I route a fair number of top layer traces under the T4.1. Obviously, I would have worse issues with a cutout. At least I could route on the bottom.
 
Paul noted with some surprise another imxrt that was 1011 (?) that had all components topside - if it could be done and stable - it would just take up more topside PCB space - and perhaps reduce the number of pins that could be routed.

Also noted was using the current cost effective PCB layer and design the T_4.1 was only possible using the larger MCU chip to manage routing. IIRC the ethernet alone took ~12 pins - plus the others the T_4.1 presented was the max possible even under that MCU.

The larger 1170 has another 90+ pins available and a bit larger MCU body - that won't fit in 0.7" wide with pins on both sides.
 
There could be a "sandwich" SMD adapter board with cutouts when using castellated pins
that just "extend" the pins down a level
https://hackaday.com/2019/01/18/oreo-construction-hiding-your-components-inside-the-pcb/

this way it's much easier to surface mount the teensy,
it could also be used on the current teensies for easier smd mount
and to protect the backside components.

The alternative is using surface mount 0.05" pins but that is little harder to solder,

This cutout pcb adapter could be sold by PJRC.
 
There could be a "sandwich" SMD adapter board with cutouts when using castellated pins
that just "extend" the pins down a level
https://hackaday.com/2019/01/18/oreo-construction-hiding-your-components-inside-the-pcb/

this way it's much easier to surface mount the teensy,
it could also be used on the current teensies for easier smd mount
and to protect the backside components.

The alternative is using surface mount 0.05" pins but that is little harder to solder,

This cutout pcb adapter could be sold by PJRC.
I read the article, very interesting. But building a microcontroller that dissipates watts is an entirely different problem then a guitar pedal that dissipates a few milliwatts. Enclosing components under the Teensy would result in some very interesting thermals, and not in a good way. There might be a way to ventilate it but that's likely more trouble than it's worth.

But really, $1,000 for a guitar pedal? We're all in the wrong business :)
 
$1000? Try used for $6499.00 + $80 shipping. The "horsie" makes it better. And I don't think the date is related...

But Audio products are often the domain of scam artists. The placebo effect is very strong there. I recall the directional interconnect cable with embedded active electronics scam (heat shrink tubing over resistors, it turned out).
 
$1000? Try used for $6499.00 + $80 shipping. The "horsie" makes it better. And I don't think the date is related...

But Audio products are often the domain of scam artists. The placebo effect is very strong there. I recall the directional interconnect cable with embedded active electronics scam (heat shrink tubing over resistors, it turned out).
I apologize in advance for off-topic.

I've been looking for an AV receiver to replace my old one. There's a whole section on Sony's product website where they sing the praises of components that have no meaningful impact on sound quality. Like super duper diodes in the DC power supply, "copper plated" SMD resistors, and magic elements added to the solder alloy that are so secret they can't tell you what they are. Not to mention "low oxygen" cables, which is my personal favorite. Turns out that lowering oxygen content in copper much below 200 PPM makes the impedance go up, not down, and the copper becomes brittle and prone to crack failures ( https://www.copper.org/publications/newsletters/innovations/1997/12/wiremetallurgy.html)

All of this is supposed to make the product sound better? Placebo effect, indeed.
 
What the industry can sell you, it sells.
But worst of all is the health sector. Entire companies make a living selling you sugar balls.
 
but ot can be fun. I blame it all on Monster with their "oxygen free copper" BS. I recall seeing some hype about it broadening the soundstage and reducing the noise floor. PT Barnum would recognize it.

The health industry is up there for sure. But with audio, they tell you hear something and 60% of the people hear it even though there is nothing there. 30% are too afraid to admit they don't hear it. 10% visit PJRC.com. Maybe I have 60 and 30 backwards.
 
but ot can be fun. I blame it all on Monster with their "oxygen free copper" BS. I recall seeing some hype about it broadening the soundstage and reducing the noise floor. PT Barnum would recognize it.

The health industry is up there for sure. But with audio, they tell you hear something and 60% of the people hear it even though there is nothing there. 30% are too afraid to admit they don't hear it. 10% visit PJRC.com. Maybe I have 60 and 30 backwards.
I guess as long as there are people with high disposable incomes there will be other people trying to separate them from their money. NFTs are good example of this. Why is an "original" digital image worth $69,000,000 (this is for real) and all the "copies" are worth almost nothing? https://www.nytimes.com/2021/03/11/arts/design/nft-auction-christies-beeple.amp.html

Here's an idea. Paul should build a proto Teensy 1170 board, create a NFT for it, and auction it off for a million dollars. Happy April 1st!
 
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