Let's talk of possible new accessory boards

PaulStoffregen

PaulStoffregen

Well-known member
Robin and I have a meeting with SparkFun next week. Among topics we'll likely discuss is possible new hardware.

Teensy 5.x is not up for discussion (NXP isn't shipping Cortex-M85 yet). Neither is RT1170 up for discussion right now, as the chips are physically too large. Please DO NOT waste time bringing these up. Yeah, I know everyone wants to talk next-gen Teensy, but this thread is meant to be about useful accessories.

I would like to hear your thoughts on possible accessory boards. Historically Teensy 4.x has only 2 such boards from PJRC, Audio Shield and OctoWS2811, plus some unassembled kits. Today I believe SparkFun only Teensy specific accessories are QWIIC adaptors and an Arduino Shield adaptor.

If Robin & I could talk SparkFun into making only 1 or 2 more (ideally to get started with more to come later) which types of accessory boards would you want to see? It doesn't have to be something you'd personally use... think of all the times we get questions on this forum where someone is struggling to make a specific type of peripheral work. What boards could SparkFun make that would help the most?

(....I'm intentionally holding back my own list for now because I really want to hear your unbiased thoughts first....)
 
Just a wish list:
Something like the old propshield board with and without the IMU. Would be nice to have a DAC on board it :) so things like speech can be used. As for IMU probably something like the BMI270 and the newer BMM350 since the BMM150 is no longer recommended for new designs. Don;t think NXP is in the IMU business anymore.

Looking forward to see your list:
(....I'm intentionally holding back my own list for now because I really want to hear your unbiased thoughts first....)
Click to expand...

EDIT:
Maybe a SPI display adapter for boards like the ILI9341/9488 and the ST7796 since they all have the same pin outs - the board could have one of the chips on board to avoid issue with spi between display and touch

Teensy to arduino header board - maybe t4 to uno r3 headers with additional things on it like for CAN and qwic connector

Teensy to arduino mega adapter for the t4x with can/canfd/qwiic and may usb connector? Stretch it on this one.

Maybe offer boards like you designed for debugging with 3 slots with t4 connectors etc Those have really come in handy - same for the t4 versions

@KurtE and I have some really interesting adapter boards for those 3/4 pins adapters to interface with RA8876/RA8875 parallel boards
 
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PaulStoffregen said:
Robin and I have a meeting with SparkFun next week. Among topics we'll likely discuss is possible new hardware.

Teensy 5.x is not up for discussion (NXP isn't shipping Cortex-M85 yet). Neither is RT1170 up for discussion right now, as the chips are physically too large. Please DO NOT waste time bringing these up. Yeah, I know everyone wants to talk next-gen Teensy, but this thread is meant to be about useful accessories.

I would like to hear your thoughts on possible accessory boards. Historically Teensy 4.x has only 2 such boards from PJRC, Audio Shield and OctoWS2811, plus some unassembled kits. Today I believe SparkFun only Teensy specific accessories are QWIIC adaptors and an Arduino Shield adaptor.

If Robin & I could talk SparkFun into making only 1 or 2 more (ideally to get started with more to come later) which types of accessory boards would you want to see? It doesn't have to be something you'd personally use... think of all the times we get questions on this forum where someone is struggling to make a specific type of peripheral work. What boards could SparkFun make that would help the most?

(....I'm intentionally holding back my own list for now because I really want to hear your unbiased thoughts first....)
Click to expand...
Personally I would really like to see an update to the Octo Board that is compatible (stackable) with the Audio board. More outputs that are compatible with the Mappable 4.0/4.1 pins would be brilliant especially now that we have the new libraries. Also my preference would be to have a different output than the RJ-45s. Maybe screw terminals optional?

Excited to see anything that you put out as Pjrc hardware is so reliable, but that’s my initial thoughts.

Regards
 
Sam Halvoe said:
How about a pre-assembled Ethernet kit or an assembled Ethernet board?
Click to expand...
Consider making it a power-over-ethernet connection, not just Ethernet. That would enable distributed sensor arrays (add qwiic connector for easily employing i2c sensors!) all via a single cable for both data and power.

Also, you could stack on an audio shield and maybe build yourself a distributed audio-over-ethernet system. Fun!

Ethernet makes so much possible. And everything should have qwiic.
 
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A MIDI shield! With full size 5-pin DIN.

Stacking this along with an audio adapter, all those synth ideas can finally be played without PC.

MIDI, ftw!
 
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A Bluetooth and/or WIFI module (with examples) to make wireless easier for Teensy!

SInce you'd want to be totally wire-free, we also want to power ourselves from battery. So, you'd also want to add a LiPo battery connector to this board, along with a lipo charge circuit...like Adafruit puts on so many of their boards.

(And add a qwiic connector, of course)

Set the Teensy free! Wireless plus battery!
 
An FPGA peripheral interfaced to the memory bus might open the application space quite a bit.

Comms, displays, and memory could be pretty useful too. But try to avoid using the SPI or FlexPWM2 pins for any accessories. I use those for my own devices, and probably many other users do too.

If you and/or spark fun wouild be interested, I can suggest a set of DAQ cards also.
 
I agree with @chipaudette suggestions!

A WiFi and/or Bluetooth module with native library support included in the TeensyDuino install would be excellent! Something similar to how the ESP-32 works (but with an external module).

I also like the LiPo charger idea. It is useful not only to set the Teensy free from the cables, but also to act as a backup power source in case of power outages.
 
PaulStoffregen said:
If Robin & I could talk SparkFun into making only 1 or 2 more (ideally to get started with more to come later) which types of accessory boards would you want to see? It doesn't have to be something you'd personally use... think of all the times we get questions on this forum where someone is struggling to make a specific type of peripheral work. What boards could SparkFun make that would help the most?.
Click to expand...

In the past there was an I2C display (TeensyView):

It would be nice if there was a base Teensy 4.1+ board that has a QWIIC port for I2C without needing the shields that Sparkfun makes. It would be nice if there were 2 jumpers that could allow the I2C caps to be enabled or disabled.

It would be nice if there was a combined prop board for the Teensy 4.0 (or 4.1 depending). Lets see:
  • Lipo charger
  • Button battery (CR2032, etc.) for the real time clock
  • On/off button access (presumably program button also)
  • For a real prop shield, it would be nice to have at least one momentary button and maybe mount for a potentiometer
  • Motion sensor for the prop board, but with QWIIC I2C, you can add it later.
  • Neopixel/Dotstar pins like the old Teensy prop shield (or LC)
  • I find myself at times laying out boards with connections to 2 SPI ports to do the Teensy eyes (obviously for the 2nd SPI port, you can't just use a standard mounting header on the Teensy 4.0, but it is possible with the Teensy 4.1)
  • Maybe low cost audio like the components from the PT8211 board
  • Wifi/bluetooth would be interesting. For me, bluetooth is more interesting than wifi since I can interact with it via my phone, but I can understand the desire for wifi as well.
  • It would be nice if this board came with an option of pre-soldered stacking headers (to go with a Teensy with pre-soldered headers as an option). After all, I went with the Teensy initially because you had the option of soldered in headers. Sure, I can solder now, but if you want to reach new users, having a non-solder version can be helpful.
  • If it based on the Teensy 4.1, it probably doesn't need a separate flash memory chip, but I do recall using the memory on the old Teensy Prop board back in the day
For reference, the Adafruit feather prop wing has:
  • Feather prop wing URL
  • Integrated RP2040 + prop board
  • Snap-in 3 pin neopixel port (can attach JST headers)
  • 3 pins that can drive 3W each for LEDs and/or servos (these pins need to be PWM pins)
  • Accelerometer built-in
  • Class D audio amplifier
  • Pin to turn off external power for hibernation
 
Hmm ... an interesting challenge! The comments below are very much IMNSHO...

An awful lot of things one might want to do are already catered for by existing breakout boards, so it's not clear that re-inventing those wheels would be particularly helpful. I'm thinking here in terms of a few channels of ADC or DAC, GPIO or I²C multiplexers, etc.

One of the great things about Teensy is its teensyness, so variants with additional sockets to break out peripherals that already have pins or pads wouldn't be attractive.

Reading various posts, I'm not sure of the practicality of battery operation - a power bank is good for a few hours, beyond that is problematic, since we're looking at a system that's attractive because of high speed, rather than low power. Even the RTC seems tricky / impossible to get "properly" working (i.e. a year on a coin cell). Again, LiPo supportboards of varying quality are already a thing, anyway. A future Teensy LP (low power) would perhaps be nice, but that's out of scope - not an accessory.

What might be very useful is a rather dull backplane / expansion offering.

The backplane would reproduce the Teensy 4.1 pinout but with 0.1" between the two rows of each slot, rather than 0.7". Possibly the slots would have extra signals for routing from the pads on the back of the Teensy, e.g. for users who want SPI3 rather than QSPI. Slots would be spaced to fit Eurorack, since so many projects are synth-related. Expansions could then pick off the signals they need: mux and analogue for a set of knobs, I²S / TDM for audio, SPI for displays, 5V <-> 3V level shifters for awkward peripherals, etc.

The first two expansions would be a Teensy 4.x motherboard and a prototyping board. The motherboard would have the SD slot at the front, not the USB - SDIO being less tolerant of being routed over longer wires. It could perhaps have USB host and Ethernet socket options to make use of the available front panel space.


Not really related to new accessories, but it would be good to have an improved Audio Adaptor ready to go when existing stocks run out. (You'd have to keep it quiet or everyone will just wait until it came out ... unless it's sold at a small premium to start with.) Improvements would be:
  • better power isolation / routing, particularly for the SD card - at the moment SD writes can put significant noise on the inputs
  • headphone output capacitors to avoid the frequent issues with people grounding its virtual ground; slight compromise on audio quality, maybe, but the experienced user could always short them out, and in any case is unlikely to be using the adaptor for audiophile applications
  • better support for multiple simultaneous adaptors, in the form of more tracks and pads that can be used to configure the I²S and I²C signals (a multi-channel TDM adaptor might be nice, but there is existing support, albeit not available from SparkFun - maybe they could adopt one of those?)
 
We all run out of pins.
How about 16-32 mux'd inputs, digital or analog.
16-32 mux'd outputs, digital or analog.
Implemented with shft reg's or mux's.
Would be nice if performed voltage level translation. Stackable for expansion. Connectors.

A hat with SPI (and/or I2C) connector(s) and cable(s) to leverage Sparkfun displays.
 
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After doing some work comparing the Teensy 4 with a few of the Arduino's, and the Stm's, I would like to offer my two cents/sense on the stackable headers. The stackable headers limit you to a really poor sort of electro-mechanical contact, they set you up for some serious thermal issues, and the idea of this cute stack toy sitting on your desk is not appropriate to the mechanical form factor of the Teensy.

Here are some images of how I use the Teensy 4. The design is perhaps instrumentation oriented, but I think it is general enough to cover a lot of use cases. The design files will be posted to my github in the next week or so.

This gives you
  • a pair of keyed headers for the SPI with separate pins for CS, the 2x10 at the top also has the FlexPWM2
  • a 2x4 header with diode protection for the first four analog inputs with grounds
  • a 2x6 header for the remain AIN or more DIO, with ground and 3.3V
  • A 1x16 for pins 0-12 and ground,
  • a keyed connector for current limited 5V power with over current detection,
  • a keyed connected for 3.3V power,
  • a keyed connected for direct 5V usb power,
  • a precision voltage reference,
The top connector with SPI and FlexPWM gives you a lot of control capability for your custom designed peripherals. I use it for my instrumentation boards for example.

My repertoire for instrumentation are an 16 bit 1MSPS InAmp, 18 bit sonar or acoustic holography, a S11639 LCCD and just now finishing up a new and I think definitive design for the TCD1304 LCCD (with some input from Toshiba). Next up is single photon counting and tagging, suitable for fluorescence lifetime measurements, and after that a 16bit 1MSPS Waveform generator and the 18 bit version of the InAmp and Waveform generator. At the moment, I'm particularly excited about the photon counting and tagging, it replaces $60K of research funding with about $120 in parts. And of course, all of this is going up on github as I finish and test each.


Controller_T4_R3EB_3D.jpg


1750852425652.png
 
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PaulStoffregen said:
If Robin & I could talk SparkFun into making only 1 or 2 more (ideally to get started with more to come later) which types of accessory boards would you want to see?
Click to expand...


Probably my first answer would be, something, that you would find fun in doing! Whatever that is.

For me, I would probably start off with some new breakout board for the Micromod. That has a mix or match of the three that I use most shown below:

1750855971699.png

At the bottom is your original one we did a lot of testing with. The top one is one that @mjs513 and I did that I had fabricated and partially
assembled at PCBWay. And the middle one was a quick dirty one I did when I was adding Teensy Micromod support to zephyr. I wanted one
that had the Arducam camera connector setup, plus SDIO SD Card, display and possibility to plug in a Audio board.

What I would like to see in the breakout is:
a) Teensy pin numbers (maybe the standard Micromod numbers somewhere)
b) SDIO adapter
c) USB Host adapter
d) Display adapter, my two have both the ILI connector layout as well as the Adafruit layout, but ...
e) camera Adapter
f) Connector that has the T3.2/T4 layout... more particularly Audio/maybe propshield/...
g) sufficient power....
h) And I know others would like a USB-C connector...

For Teensy 4/4.1:
I believe @mjs513 and maybe others mentioned how useful some of your multi Teensy connector boards are. I often use one or
more of them to do quick and dirty experiments. Note sure which one between the 3 row or the 5 row...
1750857368355.png


Example: Quick and dirty adapter that I plugged into one, that I used to experiment adding a second SDIO card reader...

3) some adapter/breakout for: wifi/bt - maybe something with a Murata 1DX, could have lots of other fun things on it as well 😉
1750857996818.png

This board from Arduino (Nicla Vision) has the STM32H747 processor and 16mb flash on it, but disregarding those, it also
has Murata on it, plus GC2145 camera, Microphone, IMU, TOF and the like on it. And it has a small footprint. So maybe something
like a super propshield?

Please pardon the Red tape in some of these photos... I did that to tell me that these are locked Teensy boards.

Kurt
 
Note: in the above, I am assuming that something like a new T4.x, that exports more of the IO pins is probably not an option?
Like maybe some form that exports a similar set of pins as the DevBoard 5 does?

If it is an option, not sure in what form factor should be?
Longer? Double Rows? High Density connector(s) on the bottom, MiniMod ?

While I am not a big fan of these higher density connectors, as they stretch my soldering skills beyond my limits, they do allow one
to expose a lot of signals in a small footprint, and like the Micromod or Portenta makes it easier to create several different shields.
 
I am also not a big fan of high density connectors. I only use them for customers.

Since tariffs, I am back to doing assembly for small quantities. I just order the pcbs with stencils, JLPCB will let you size the stencil to the board, great for hand assembly. And now, everything is a lot faster and cheaper than it was having them assembled over there. And best of all, instead of depending on sponsors for my personal projects, I am marching through through the backlog on my own.

So, anyway, now that I have to build them myself, something with pitch finer than 0.1" will most likely be SMT.

Reflow ovens are now about $600-$800 on ebay. But it is sill super worth it to have one. Just stick with 0603 (or bigger) wherever you can, and life is good.
 
Here is my 2c on things that can be useful for the Teensy platform

1. For add-on's :
  • I'd put my vote up for WiFi over SDIO/SPI and BT over UART with a module such as the Murata 1DX and it's variants found on many Arduino/Pi boards
  • Another would be a small HMI board with a higher speed display interface such as 8 bit wide 8080, pack with other things like a small speaker, a MIC, and some other sensors.

2. Another thing that I would find very useful is a general purpose carrier board for the MicroMods.
The only way to use a MicroMod on a custom PCB is to obtain the M.2 carrier + standoff and have them shipped out to be soldered on, something that makes low quantity production very expensive
So a carrier that breaks out all the pins to TH would save that entire PCBA cost
Here is a plain example I came up with a few weeks ago
1750877078591.png



3. Last but not least, a T4.x variant with SDRAM on board and more pins (such as 16 bit eLCDIF pins exposed)
Given the work already done to get SDRAM working, only the hardware is missing to make that happen
Something like this seems like a good form factor with a fair amount of pins - https://forum.pjrc.com/index.php?threads/diy-teensy-sdram-solder-yourself.76887/
 
As a very basic board/kit a USB host kit similar to the ethernet one would be nice. It'll only be a small PCB with a USB-A socket and a header, possibly a capacitor on the power pin, but would greatly lower the barrier to using that port.
 
I'd like to see an industrial input/output accessory—something like the ST CLT01-38SQ7. There is a wide range of sensors that can't easily be adapted to a microcontroller due to signaling requirements, such as voltage and minimum current. Even smart sensors using EtherCat (Modified Ethernet Frames) or IO-Link (Modified Serial) can be a challenge at times for receiving simple information. T4.1 is technically more powerful than the lower-end Programmable Logic Controllers used in factories. AutomationDirect has adapted a standard Arduino form factor into its lower-end 1000 series PLC.
 
I would like to see a Teensy 4.1 Pro. Just export all pads/IOs while still doing the heavy lifting (in terms of BOM). No connectors (like USB, SD-Card) aside from pins. Export hardware debugging. With todays availability of cheap PCB manufacturing there should be a version of teensy that is for PCB motherboard soldering and not for breadboards. So when you have finished all the tinkering with the original teensy 4.x there is a path for going pro.
 
whitebengal said:
I'd like to see an industrial input/output accessory—something like the ST CLT01-38SQ7. There is a wide range of sensors that can't easily be adapted to a microcontroller due to signaling requirements, such as voltage and minimum current. Even smart sensors using EtherCat (Modified Ethernet Frames) or IO-Link (Modified Serial) can be a challenge at times for receiving simple information. T4.1 is technically more powerful than the lower-end Programmable Logic Controllers used in factories. AutomationDirect has adapted a standard Arduino form factor into its lower-end 1000 series PLC.
Click to expand...

The CLT01-38SQ7 datasheet shows a HTSSOP-38 package. That should be okay for hand assembly.

If someone wants to sponsor it, I am willing to design the board and make a few, and post the files to github.

It seems like total time to first boards should be about 1 month. One week for analysis and design, one week for assembly, test and program, and a week and half in between to get the pcbs and parts.
 
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