Improve 5V sourcing section

[Frijol]

There is a very small mention that you can get 5V from T2 here: https://github.com/tessel/t2-docs/blob/master/Hardware/Tessel_2_Overview.md but it could stand to be more helpful, as here: https://forums.tessel.io/t/accessing-5v-on-tessel-2-powering-tessel-2-with-wires/2368

It may also be useful to note that you can source an external 5V using the Servo module's breakout (wise for applications that might require more current than T2 should safely provide, such as moving motors).

[soapdog]

Another important highlight would be how to power Tessel 2 from 5vin, I know it is quickly described there but a linked tutorial would go a long way with people who are new to DIY electronics (something like iFixIt guides that contain copious amount of annotated high quality photos).

I know this is more work but you can't never have too much documentation or photos 😸

[mbrevda]

That is down. Is there anywhere else that information might be available?

[Frijol]

I don't think it's posted elsewhere (unfortunately) but I can just tell you:

Powering accessories that need 5V

from the pin (things that don't need a lot of juice)

In the image above, the yellow box is around the 5V pin. You can source 5V power from there for, e.g. powering a PIR sensor or other not-very-power-intensive device. It's drawing 5V from the same 5V USB power that's generally used to power the Tessel 2 board. This is why you don't want to use this for power-intensive applications (e.g. for moving a motor)– you'll draw too much current and might cause the main board to not have enough power to run.

from external power (things that need more juice, like motors)

It's not a great idea to run motors off of the 5V pin on Tessel 2 itself (see above explanation) but you can control things with Tessel and power them from a different source. One of my favorite ways to do this is to use the Tessel Servo module. The Servo module plugs into the Tessel to receive instructions, but also has a barrel jack to source external 5V power– so it's not drawing from the Tessel's power. The long 3-wide column of pins is designed to control one servo motor per row. Accordingly, each row has a 5V pin (labeled +) and a ground pin (labeled -).

You can use this board independently of Tessel, plug in the barrel jack, and use this module as a breakout for 5V power.

Powering Tessel 2 with a non-USB 5V source

In the green box but not in the yellow box, you have GND and 5Vin– these are for powering the Tessel 2 board without using the USB plugin– e.g. AA batteries. Sparkfun has a nice overview of how this can work in general: https://learn.sparkfun.com/tutorials/how-to-power-a-project and something like this: https://www.sparkfun.com/products/12083 would work well.

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Hope that helps, but please feel free to ask more questions.

Huge bonus points if you add this info/any tutorial in the docs!

[mbrevda]

This is awesome and perfectly helpful, thanks!

[arushi019]

HI @Frijol @HipsterBrown ! What should we do to close this issue? We are not able to really understand here what to do.

[Frijol]

Good question @arushi019! Here's what it takes to close this issue:

1. Make a new file in t2-docs to hold this information.

Should be under "Hardware" such that it shows up here in the sidebar of tessel.io/docs, even with Modules and Tessel 2 Overview:

– so, a new markdown file in this folder: https://github.com/tessel/t2-docs/tree/master/Hardware

It should be called something clear, short, and descriptive like "5V Power with Tessel".

(It could arguably go in the Tutorials folder instead. Which is more appropriate? You decide.)

2. Read and understand the notes above

Ideally, use the information above to:

• Source 5V from Tessel's main board
• Source 5V from a Servo module
• Power Tessel from a 5V source like a battery pack

Take pictures of the setup and/or make Fritzing diagrams.

However, that might be pretty time consuming. You don't have to do pictures and diagrams as long as you (a) understand everything and (b) are able to describe it clearly in writing. I'd happily merge a PR that just uses the diagram I made. Perfect is the enemy of good. Better to have something in the docs than nothing (and a really nice pull request in progress). Remember that you can always add improvements (pictures, more descriptions) later in a separate pull request if you find you have time.

3. Explain how to use 5V with Tessel in your markdown file

These three things must be clear: how to...

• Source 5V from Tessel's main board
• Source 5V from a Servo module
• Power Tessel from a 5V source like a battery pack

Minimally, you could copy/paste my comment and check it for spelling and clarity. But if you want to go further, here are improvements you could make:

• Give it a more formal, textbook-like tone
• Think about what people are looking for when they arrive at this page, make sure headings etc. direct them to what they need
• Give examples

...but again, start with the minimum. Make a PR that has just the basic stuff, and submit it. You can add more later, if there's time.

Hope this helps, and please ask more questions if they arise!