Teensy 3.0 versus Teensy 2.0

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wsg
 
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Teensy 3.0 versus Teensy 2.0

Post by wsg »

Hi,

I want to replicate a project that used a Teensy 2.0 previously. Would the Teensy 3.0 be backward compatible for the project? Thank you. :roll: :wink: :wink:

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adafruit_support_rick
 
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Re: Teensy 3.0 versus Teensy 2.0

Post by adafruit_support_rick »

That really depends a lot on the project. It has a better chance of working if it's something simple, or if it doesn't directly manipulate any hardware registers.

You might have better luck with this question over at the PJRC forums.

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paulstoffregen
 
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Re: Teensy 3.0 versus Teensy 2.0

Post by paulstoffregen »

Looks like same question (lacking any specifics about the project) also went to my inbox several hours before posting here.

Here's the answer I wrote:


Teensy 3.0 is not a 100% compatible drop-in replacement for Teensy 2.0. It's not even the same physical size nor the same number of pins, so of course some careful review of the design is needed to know if it will be compatible.

There are numerous differences. Usually the most significant is Teensy 3.0 uses 3.3 volt I/O, where Teensy 2.0 uses 5 volts. Most digital circuits can accept either, but if digital signals are sent from circuitry back to the Teensy, you may need to add a current limiting resistor or buffer chip to protect the Teensy 3.0 from the 5 volt signal.

If you use the analog inputs with internal voltage reference, the voltage range is 1.2 volts instead of 2.56 volts. If you use the power supply as a reference, the range is 0 to Vcc... so things like a pot or resistive temperature sensor will automatically scale, but measuring absolute voltages like a battery will give different numerical results.

Teensy 3.0 is a much faster 32 bit CPU. If you're using Arduino, most code is remarkably compatible. Most of Adafruit's libraries work. However, some other libraries do not work and have not been ported. Here's the official tested library list.

http://www.pjrc.com/teensy/td_libs.html

If you do need some help, of course it's fine to ask on the forum. This is the place to ask:

http://forum.pjrc.com/forums/2-Project-Guidance

However, you can only expect a good answer if you write a good question which includes enough technical detail or a good enough description of what you're trying to accomplish. Vague questions can't be be answered effectively.

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adafruit_support_rick
 
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Re: Teensy 3.0 versus Teensy 2.0

Post by adafruit_support_rick »

Thanks, Paul!

@wsg - Paul is the guy who knows.

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