Teensy3 development board & arduino shield impressions
For Teensy 3* Proto Board & Arduino Shield V1.1
Note, I just got this board, and looked at it a little, so it isn't a full fledged review, just my initial impressions. I haven't tried it with any Uno shields at present.
I bought the fully assembled version of the board, and came fairly quickly.
I really like the finish of the board. It reminds me of the Adafruit perma-protoboards (white board with through hole plating).
In terms of what you get with the fully assembled board, you get the board with all of the headers installed. Inside the inner headers, is the 7x2 male headers for the Teensy underside pins. These come out of the header, and you would need to solder these to your Teensy 3.x. If you are like me, and have a Teensy where PJRC soldered in the pins, all of those pins work, but you will need to solder in 4 pins to get access to VUSB, AREF, A10, and A11.
I do have a few minor niggles, in terms of the design:
1) The board does not provide headers for the i2c aux. pins next to AREF. It would simple to solder in a 2 pin header on the current board, but it would be nice in the future if a longer header row were supplied. A5/A4/AREF should also have a parallel connections for pins 0..13.
2) Speaking of i2c, on the Arduino Uno and other boards, users do not need to supply resistors for A4/A5. It would be nice if the board had a jumper (pin or solder headers) that we could turn on 4.7k resistors for A4/A5 so that i2c can be used out of the box.
3) The power jumper sticks out, and might get bent or get damaged in a close fitting enclosure. I would prefer the jumper to be on the board, and not sticking out like a sore thumb.
4) In terms of power, it might be useful to have a plug for 3.7v li-po batteries, possibly adding a charging circuit if you have a USB power connection. I am unsure whether it would be better to plug the li-po battery directly into VIN, or do a boost to 5v, before plugging it into VIN.
5) Similarly to #1, there are 2 pins to the left of the reset pin that are not attached. One pin is IOREF that probably would be useful to export. I'm not sure what the other pin does.
6) I tend to prefer protoboards that are laid out like breadboards, so you don't have to make solder bridges to do some connections. But others prefer protoboards that have no connections.
7) One thing that might be interesting to some people, is if the VUSB pin were located near where the VIN pin is. If they cut the solder joint on the Teensy that connects VUSB and VIN, on the Teensy they are fairly close together so you can easily bridge them. On this board, the VUSB on the other side of the board, and you would need a longer wire to attach them. Perhaps the solution is having a 3 way jumper (solder. dipswitch, or pin) instead of 2 way, that would not connect either power supply to VIN, connect VUSB to VIN, or connect the external power supply.
8) I haven't gotten into ICSP/SPI yet, but for the assembled board, it might be useful to put a 2x3 header block to easily attach the ICSP/SPI cable. Obviously, the Teensy doesn't use ICSP like Arduinos do, but perhaps people use it as a convenient way to attach SPI devices.
9) The pins for the external power supply are a little longer underneath the board than the other solder connections. I might try to bend these down, so it sits nicer.
Response from Petit Studio | May 22, 2014
Thank you Michael for taking the time to write a review, it is quite detailed and informative.
I am glad you like the board, and you made some valid points. I don't like also the power jumper that sticks out but I found it very easy to grab this way so it's convenient while developing a project, when I am done I change it to a short straight header that is not cumbersome.