Teensy 3.6 Power supply

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Check setup() for something like : while ( !Serial )
If it has code like that it would explain what you see. It won't leave that while() until USB is activated. When USB generally desired - but not required something like this works well - in this case it waits up to 4 seconds and then continues: while ( !Serial && millis()<4000 )



AFAIK: The AGND is meant to be separate clean ground from AGND and shouldn't be tied together

This power issue was solved by holding the part in reset when the power is turned on with a capacitor - see the thread here: https://forum.pjrc.com/threads/42446...-3-6-with-3-3V
 
This power issue was solved by holding the part in reset when the power is turned on with a capacitor - see the thread here: https://forum.pjrc.com/threads/42446...-3-6-with-3-3V

Hi sorry I still am unclear what is the best way to power the teensy 3.6 safely?
I was hoping to use usb potentially. Can it be powered via the 5v usb ok?

In my project I have a teensy and a pi and a number of servos etc and I was hoping to power them all off one input even if I need to slice up some usb cables or run a distribution block from a bigger 5-10a 5v power supply.

Any advice would be appreciated.
Thanks :)
 
Running from USB power is the expected/core use of the Teensy. It typically does as well on other power - but there are certain non USB power supplies it seems (on this and perhaps another thread) that ramp up power in a way that works fine on the very similar T_3.5 and other Teensys - but may require the noted capacitor to stabilize the system to start as the power comes up for the T_3.6. If you end up not using USB and get one of those supplies, you'll know.

Scientist - Glad you got this resolved - I was reading older posts and didn't see an answer:
This power issue was solved by holding the part in reset when the power is turned on with a capacitor - see the thread here: https://forum.pjrc.com/threads/42446...-3-6-with-3-3V
 
Thanks Defragster! most appreciated.

I am trying to work out the best way to power the teensy and a pi and a pca9685 shield to drive 6 servos.. I was hoping to do it from one power plug in the wall and some distribution blocks but not too sure yet.. I have some other power requirements like a small peristaltic pump and leds etc..
 
Usually the best approach involves getting the power supply physically close to the motors and connecting them with short wires directly to the power supply. Longer, separate wires can connect power to Teensy & Raspberry Pi, or you could power the controllers from separate power supplies, as long as they all share a common ground.

The thing to avoid is long wires from the power source to the motors, and especially all that motor current flowing through the same ground wire that connects between the circuitry & motors. You want the motors to get their power directly from the power supply.
 
max limits supply and current

Hello Paul,

I have been using the Teensy 3.6 and is really a nice developed product.
After checked the schematic circuit found the voltage regulator to be the LP38691 in the datasheet it is rated to be a 500mA and 10Vmax input voltage.
But in your card it is written max 6V and 250mA, the current I expected to use does not pass the 100mA but would like to use 4 D cell for a long time data logger and you know, 4 D cells fresh new have about 6,4V that exceed the limit you suggest.
Is it save do use input voltages until 10V or not concerning thermal issues?

Thanks,
Timóteo
 
Hello Paul,

I have been using the Teensy 3.6 and is really a nice developed product.
After checked the schematic circuit found the voltage regulator to be the LP38691 in the datasheet it is rated to be a 500mA and 10Vmax input voltage.
But in your card it is written max 6V and 250mA, the current I expected to use does not pass the 100mA but would like to use 4 D cell for a long time data logger and you know, 4 D cells fresh new have about 6,4V that exceed the limit you suggest.
Is it save do use input voltages until 10V or not concerning thermal issues?

Thanks,
Timóteo

See this post - the T_3.2 uses the same part - the specs are just reduced as noted to assure function and proper heat dissipation.
 
Teensy 3.6 on board voltage regulator

I'm using the Teensy 3.6 for a battery powered data acquisition system. I'm having problems with the on board voltage regulator. The data sheet claims a voltage drop < 100mV when the current is around 100mA. The Teensy 3.6 should absorb less than 100mA @180 MHz, but I measure a voltage drop of about 500mV. When powered by a LiPo battery and the battery voltage is below 3.8V the on board nominal 3.3V is reduced according to the relation: Teensy regulated voltage = Vbat- 450/500mV.
I tested many Teensy boards and the all show the same behaviour, is it normal?

Regards
Paolo
 
Is the 3.8V measured under load or out of the circuit? What is the LiPo source/size/##? At 3.8V it isn't freshly charged. Is the drop the same when the cell is fresh?
 
I tested many Teensy boards and the all show the same behaviour, is it normal?
It's what I would expect. In front of the voltage regulator is a diode which adds an additional voltage drop (about 300 mV).

3HpvRxj.png
 
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