Teensy not blinking - how to proceed?

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gavspav

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I just got a Teensy 3.2 and a SmartMatrix SD Shield.
I cut the strip between Vin and Vusb and soldered them together.
Stupidly (in retrospect) I didn't test the teensy before soldering.

Anyway I checked the solder visibly and it looked ok, plugged the teensy in via usb and nothing.
I've checked the voltage between USB+ and ground and it reads 6V
But there is no blinking led and I can't upload any sketches to the teensy.

I have noticed that if I touch the SPI-CLK pin with my finger, the led glows faintly.

Can anyone tell me what the next step is please? Feeling foolish.
 
First, use your voltmeter to check if the power at VIN and also at VUSB (the pad near the USB, not on the edge of the PCB), and also at 3.3V.

If the board is new and has never been programmed, it should start blinking when power gets to VIN, which feeds the voltage regulator that produces the 3.3V power. Everything actually runs on 3.3V.
 
Its hard to get to the pads because of the smartmatrix shield!

There is no voltage between the Analog Power 3.3v pin and ground.

Between the Vusb hole and ground is 6v.

I don't think there is any voltage at the Vin pad but its hard to reach.

As I've cut between Vusb & Vin does that mean I must use an external power supply at all times?
 
Yes, Vin must get always power.
You cut the link only if you wanted to run teensy without USB connection.
BTW USB should be 5 V and not 6 V. Did you put 6 V on VUSB?
 
I was following these instructions

I have a 5v power supply but the open circuit voltage is 6v. Can the teensy 3.2 handle this?

I've ordered another teensy as I think I must've killed the first one.

I'd really rather not make the same mistake (whatever it was?) again though!
 
gavspav said:
I was following these instructions

I have a 5v power supply but the open circuit voltage is 6v. Can the teensy 3.2 handle this?

I've ordered another teensy as I think I must've killed the first one.

I'd really rather not make the same mistake (whatever it was?) again though!
Click to expand...

Only to be clear:
you powered the whole system by SmartMatrix and there is _NO_ USB cable connected,
then the Vin pin (top right pin) should have between 3.7 and 6V on T3.2, and the teensy should be blinking (if new from factory).
If there is nothing on Vin then your SmartMatrix shield does not power the teensy and the problem is there.

Also, the VUSB pin (inside pin between to AGND and USB connector) should have nothing, as there is no USB cable connected.
As soon as you plug in a USB cable, this VUSB pin should go high.

If you have not done so, you can find the schematic on PJRC website.
 
I plugged the power supply in and the usb cable so I could upload the smartmatrix sketch.
I then realised I couldn't upload the sketch.
I then realised the teensy should be blinking anyway and posted on here.

Once I have separated the vin & vusb, do I need to plug in the separate power supply to upload a sketch? I assumed I did.
The Teensy seems to accept up to 6v so I'm not really sure how I fried it.
Maybe I'll find out when the next one arrives!
 
gavspav said:
I plugged the power supply in and the usb cable so I could upload the smartmatrix sketch.
I then realised I couldn't upload the sketch.
I then realised the teensy should be blinking anyway and posted on here.

Once I have separated the vin & vusb, do I need to plug in the separate power supply to upload a sketch? I assumed I did.
The Teensy seems to accept up to 6v so I'm not really sure how I fried it.
Maybe I'll find out when the next one arrives!
Click to expand...

Yes,
to upload the sketch Teensy must be running, i.e. powered via Vin (Smartmatrix). USB is in your case NOT powering the teensy (as trace is cut).

but you can still check the voltages, all relevant pins are reachable from top.
 
I've bought another teensy + shield, soldered them up and still can't get it to work.
The teensy blinked before I separated vin & vusb and soldered the shield on.

With the multimeter I get 5v between 5v and ground, 3.6v between vusb and ground but nothing between vin and ground :-(
No blinking.
 
pins.jpg
If you apply 5v directly to the vin and gnd pins on the teensy, does blink start? Such as from a separate power source, like a 4v or 5v battery?
 
So, what ever point you are supplying power and gnd connections to on the shield, is not connected to the Vin or gnd of the teensy for some reason.

If you apply the separate power to the teensy vin, but use the gnd of the shield, does teensy blink? Does the shield have different power pin options, are they broken out at different points?

Is that diode in the right way round? does it impact on this issue?
 
Last edited:
I think you might be right about the diode. I'll check it out tomorrow. Thanks very much for the help.
 
Tennsy 3.2 not blinkin

mortonkopf said:
View attachment 6146
If you apply 5v directly to the vin and gnd pins on the teensy, does blink start? Such as from a separate power source, like a 4v or 5v battery?
Click to expand...

Hello everybody, I have the same problem but by applying 5V directly to the VIN nothing changes. The Teensy is brand new, it was blinking until I loaded the first sketch and than never more.:confused:
 
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