Is there a market for a Teensy 3.1 48 pin ARM stamp?

Status
Not open for further replies.
We must be careful comparing apples and oranges, or Teensies and Photons.

I havnt tried the Photons, BUT in a thread devoted to the question of accessing every single pin in a 48 pin formfactor and probaly use every ounce of cycles the core cand deliver, a CM3 that uses a fair amount of resources and pins for talking to a wifi chip, well ... to me that sounds like the answer to a different set of requirements.

Reading a lot of the chat on formfactors, pinouts, and ++'s and devtools all I can say it depends, depends on your background, the size of your projects, if cmd line tools feels homely and right or scary and arcane. If you prefer the small size, fairly complete set of easily useable libraries in a basic GUI that gets .... annoying ... as the project gets large, or you want a platform with everything available, until you start ranting how obscure Eclipse is. Personally I do projects that benefits from processor speed, memory but not a huge amount of pins.

Its all compromises, we live with them and no chise will ever be perfect.
 
I've taken the idea from iwanders
Perhaps it would be nice to create a small PCB which extends the Teensy form factor and makes the bottom pads more easily available (the Teensy is placed on top of this PCB). With an internal cutout we can ensure that these bottom pads are easy to solder.
and ordered it from oshpark ($8.30 for 3pcs)

1-P1000897.JPG 1-P1000901.JPG 1-P1000903.JPG

So, yes, the internal cutouts are not a problem.
 
Looks like a great way to get to everything including the crystal? Now we have to buy Teensys in 3 packs?

@hwguy - Is there a way to search OSH to find the way to order - or can you drop a link?
 
Last edited:
oshpark link: https://www.oshpark.com/shared_projects/UI47TwNf

It is not necessary to solder the pins GND, D0-D23, 3.3V, AGND, VIN to the adapter board. On the bottom side of the pcb are footprints for one resistor (0805) and one diode (SOD-123). It connects VUSB to VIN. IF you use this option, you have to solder the VIN pin to the Teensy 3.1 board and to the adapter board.

schematic

Now we have to buy Teensys in 3 packs?
or 50... You can fit it 5-6x into a 10x10cm china pcb. Dirtypcbs.com for example, 10pcs 10x10cm for $25. (= $0.5 for each adapter pcb)
 
Two weeks ago I did something similar :
conn.png
The board is currently still at OSH Park .
3 for $ 3.45 (It's smaller)
 
I was just thinking about designing this PCB when I drove back home today. Looks like you beat me to it :D Looks great! I'm happy to hear the idea worked out well.
 
Physically you can just make it point upwards... I always solder them at the top side before I put female headers on my Teensies as placing the crystal is harder afterwards (didn't require an RTC yet, so I'm not sure it works). However, thinking about this makes me wonder if the crystal's resonating is affected by the traces at the top of the PCB, various custom board designs experienced problems when traces were close or below the 16MHz crystal. Anyone know if the 32 kHz RTC crystal is affected by this as well? or would the effect be minimal?
 
I've soldered the RTC crystal on this board from the top side. The Teensy keeps the time without the main supply and 3V @ Vbat.

In the long term I plan to make (or someone else) a new revision of this board with a cutout for the rtc crystal and some other changes.
 
iwanders, good point. I forgot the crystal connection is through hole. I've always soldered it on the bottom. I should try it on top next time.


why is the pcb edge (near A14 and PGM and on opposite bottom edge) not straight? was this how it came from oshpark or was this panelized on a larger board and manually cut?
 
dremel action :)

I've tried to remove the mousebite connectors from the panelizing with a dremel and slipped off a bit.
 
I recommend a flat file for the mouse bites. Makes quick work of the bites and abrasion of non mouse bite areas is minimal. Simply pull and push the PCB edge while holding the edge of interest parallel to the file surface. 2-3 wipes later and the edge of the PCB will be smooth.
 
hwguy, can you post a pic of side view profile? I want to see how the boards stack up and what the pin header looks like. Also, since the cutout cuts a pad in half, so only the through hole will have copper right?
 
This is so slick it makes me want to come up with a project that uses all those pins just so I have an excuse to buy a handfull of these boards.
 
Now we have to buy Teensys in 3 packs?

It really is best to order in multiples. :D That way they don't get lonely and more importantly, you'll have at least 1 extra on hand when inspiration to make something strikes so you can get building right away.
 
@HWGuy

Fully bread board compatible - no end pins.
Inexpensive hardware solution.
Easily accessible VIN with jumper.
Great solution for all GPIO pins.

A job well done!

---------------------------------------------------------------------------------------------------------------------------------------------------------------
To those off topic trolls or hijackers who did their best and failed to divert this topic should learn how to focus like a laser for a solution that HWGuy easily provided.

Again, a job well done - HWGuy
;)


A solution has been provided to this topic - This topic is closed until "topper" makes another off the wall comment !!!!!!!!!!!
 
Last edited:
Status
Not open for further replies.
Back
Top