Can't communicate with Teensy 3.2 through Teensyduino

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Did you understand the concept of disconnecting power to a chip is not the same as disconnecting all the wires? I try to help....
 
Hi Paul,

I tried connecting the UC pins(25,22,24) as high impedance but the same result. Let me know my way of connecting pins as high impedance is correct or not.
Also, I got you correct or not.
tri_state.jpg
 
Hey, paul is my approach is correct or I'm wasting my time.
Also please tell me is this the default behavior of bootloader towards controller when not powered or something wrong with my circuit.
 
I understand everything Paul but I'm about to finish my project which has a huge value.
If possible kindly help me to figure this out.View attachment 7492

You need a pull up resistor on the RESET line else when the device is powered down the K20 has a floating RESET line. This could cause it to reset continuously or not even start

Also just for the record if you're not using the internal ADC you don't have to use so many components around the VSSA and VREF pins

The correct method would be to put a tri-state buffer between the MKL02 and the MK20. Then have this disabled when you wish to use an external SWD
 
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I Guess you have seen the schematic so based on that do I need to completely remove the bootloader or if its power off its okay.
As the pull-up connection of 10K is still not working in reset line.

Bootloader connections are still present though its power off.
 
The MKL02 is probably being parasitically powered. Paul hasn't programmed in a disable pin for the MKL02 so your only option is to insert a tri-state buffer chip (hint hint for the upcoming board Paul :rolleyes:)

Are you trying to get a board you have large multiples of working? If not I'd just redesign it

Also although Paul's mentioned it before I'll mention it again. Removing power/ground is not the same as disconnecting something. If you wish to disconnect something you should always buffer it.
 
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what all the pins I should connect between MK20 and MKL02 through tri-state.
Also, suggest some tri-state ic's which are easily available.
 
74LS241
All pins that output from the MKL02 to the MK20. All MKL02 input pins can be ignored.
Check the SWD protocol for which pins are inputs/outputs

Enable/disable the tristate buffer from a jumper


The MK20 should have a pullup on the RESET line
 
Hello,

I am working hours to get my teensy working.... have tryed with LC and 3.2 ... but with both I have the problem that I can not connect (port is not recognized).... I am working with Ubuntu 16.04....

I have tryed what was posted on beginning of that thread...
 
Teensy Fails to Upload or to Blink or run, Wonder if it got bricked?

Steps to get a fresh blink upload to your Teensy
*Setup IDE* {section below}
Unplug your Teensy
Close Teensy Loader.
make sure : Tools / USB Type: is "Serial"
Open and compile a sketch like below in the IDE.
When it fails to find the Teensy and says press button.
On the unplugged Teensy press and hold the button
Plug the Teensy in - Pause - release the button.

Thanks for this. I've revived an LC and 3.2 with this method.
 
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