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Grand Central on board LED documentation?
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Grand Central on board LED documentation?

by john_galt on Thu Feb 14, 2019 9:25 pm

Hi,

I have a Grand Central and am using it to learn Circuit Python.

While trying to implement a learning project I did on the Huzzah32 I ran
across a strangeness with one of the four indicator LEDs. It's a yellow one
next to the green power LED. It is marked with an "L".

Given the code below the yellow LED blinks along with my external LED.

When I tried to find out why the indicator LED is blinking I found the
Grand Central documentation below and became confused. I see the
green LED, I see the two RX/TX LEDs. However I do not see a red led
connected to ????? Where is the red LED and what is is supposed to be
connected to? Bonus question is. What is this yellow LED and what's making
it blink given my code below?

Edit: I now see further down in the documentation this

Code: Select all | TOGGLE FULL SIZE
#13 - GPIO #13 and is connected to the red LED marked L next to the USB jack.

I still don't understand whats blinking my yellow "L" LED that's supposed to be red.

Thank you for any help you can give.


Doug


Four indicator LEDs and one NeoPixel, on the front edge of the PCB, for easy debugging. One green power LED, two RX/TX LEDs for data being sent over USB, and a red LED connected. Next to the reset button there is an RGB NeoPixel that can be used for any purpose.


Code: Select all | TOGGLE FULL SIZE
import board
import digitalio
import time

led = digitalio.DigitalInOut(board.D9)
led.direction = digitalio.Direction.OUTPUT

while True:
    led.value = True
    print("On")
    time.sleep(2)
    led.value = False
    print("Off")
    time.sleep(1)

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Re: Grand Central on board LED documentation?

by adafruit_support_carter on Fri Feb 15, 2019 1:00 am

You have D9 in your code. Do you mean D13?

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Re: Grand Central on board LED documentation?

by john_galt on Fri Feb 15, 2019 11:01 am

adafruit_support_carter wrote:You have D9 in your code. Do you mean D13?


Hi Carter,

Yes I'm using D9. That's why this is confusing me. Last night I just unplugged the GC from the USB and then plugged it back in and now instead of the "L" LED and the breadboard LED blinking in unison the now blink opposite of each other. This is without changing code or altering wires. I've attached a photo.
Attachments
20190215_145407430_iOS-medium.jpg
20190215_145407430_iOS-medium.jpg (78.51 KiB) Viewed 127 times

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Re: Grand Central on board LED documentation?

by adafruit_support_carter on Fri Feb 15, 2019 11:51 am

Ah, I see. There's an external LED also. Does that LED blinking as you expect per the code? On for 2 secs, off for 1?

If you change it to D13 what happens at the row of 4 status LEDs? Your external one will stop blinking, but just focusing on one LED at a time.

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Re: Grand Central on board LED documentation?

by john_galt on Fri Feb 15, 2019 4:09 pm

Carter,

If I change D9 to D13 then "RX" and "L" LED's blink off and on.
When "L" is off then "RX" is on and vice versa.

I am printing "On" and "Off" so I would expect that the "TX" light would blink
as either "On" or "Off" was transmitted out over the USB. However it's the "RX"
LED that is blinking with the same frequency as the "L" LED>


Doug

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Re: Grand Central on board LED documentation?

by adafruit_support_carter on Fri Feb 15, 2019 4:13 pm

Hot off the presses:
https://learn.adafruit.com/adafruit-gra ... uts#step-9

I think this is all that's happening in your case. Hopefully that clears it up. The text on the overview page has also been updated.

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Re: Grand Central on board LED documentation?

by john_galt on Fri Feb 15, 2019 4:21 pm

Thanks Carter. That does explain it.

I'll consider the three Grand Central's I have as collectors items and proof
that things happen :)

Thanks again for your help.


Doug

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Re: Grand Central on board LED documentation?

by Ada485 on Wed Feb 20, 2019 12:10 pm

I guess that explains why the LED was not working. Mislabeled on the board in version 1!

This is also on a separate SPI port, so it doesn't collide with the SPI header/port used for other devices. In Arduino this is called SPI1 and by default, the SD library will know to use this for SD card interfacing. So, if you have a shield with an SD card slot, you won't be able to use that SD card connection! The library will always use the onboard SD card socket instead.

Can't you just change the pinouts in the code to be able to also use SD cards on shields? Or does it force you to use only the SD card socket here?

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Re: Grand Central on board LED documentation?

by Ada485 on Fri Mar 08, 2019 5:54 pm

Are the new batches available now revised to correct this?

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