Teensy 4.1 External Supply and Ethernet Port Pin Pitch

[japreja]

I want to make sure I understand, fully, what cutting the trace means. I would actually like to wire in a switch so I don't have to solder/unsolder frequently. This Just disconnects the USB +5 from the VIN? Will I still be able to power from USB if VIN is not connected, or must VIN be connected? If I put a switch on this, can I activate it while USB is connected?




Second, what is the pitch of the ethernet port pads, it is smaller than 0.1, is there a part number for the dual row pins I need to get?



I downloaded the image from pjrc.com and modified it slightly with the callouts, hope this is OK.

 

[MichaelMeissner]

I want to make sure I understand, fully, what cutting the trace means. I would actually like to wire in a switch so I don't have to solder/unsolder frequently. This Just disconnects the USB +5 from the VIN? Will I still be able to power from USB if VIN is not connected, or must VIN be connected? If I put a switch on this, can I activate it while USB is connected?

If you cut the trace, there will be no power connection between the USB cable and the Teensy. You have 3 choices:

• Power the Teensy externally when you are programming the Teensy;
• Disconnect your external power source and connect VIN to VUSB to use the USB power; (or)
• Add two MOSFETs so that you will use power from one source if both provide power.

I tend to use stacking headers, so I just put a stacking header on the VUSB pin, so I can use a jumper wire if desired. But a switch would also work.

If you just want to be able to turn off the Teensy 4.1, there is an on/off pin in the row of pins before the micro SD reader. Unfortunately the pinout card for the Teensy 4.1 doesn't explain those 5 pins, but if you go to the Teensy 4.0 card, it shows the pins to be:

• On/off;
• Program;
• Ground;
• 3.3v; (and)
• Vbat (for the real time clock).

If you connect the on/off pin to ground for a few seconds, the Teensy will turn itself off. If you disconnect the pin from ground, and then reconnect it, the Teensy will turn itself back on.

Second, what is the pitch of the ethernet port pads, it is smaller than 0.1, is there a part number for the dual row pins I need to get?

PJRC.COM offers an ethernet kit:

• https://www.pjrc.com/store/ethernet_kit.html

IIRC, it is 2mm pitch (i.e. slightly smaller than 0.1" which is 2.54mm).