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Gemma bootloader - again
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Please be positive and constructive with your questions and comments.

Gemma bootloader - again

by jwtadmin on Sat Apr 23, 2016 6:43 pm

This was my Saturday - take apart a broken Ikea SPOKA - build a neo pixel string - solder onto Gemma - and then spend 4 hours trying to upload code.......

Symptom - no pulsing LED
Wiring - broken all the way down to bare Gemma nothing attached
Original wiring - Neo Pixel RGBW D2, GND to GND, PWR to 3Vo, momentary switch to D1
Arduino IDE 1.6.7 - custom board manager installed for Adafruit AVR
Mac OSX - 10.11.4 - MacBook Pro (Retina, 13-inch, Mid 2014)

I have followed every guide - pressed the button gently, harder, softer, whispered to it, begged it. with no luck.

Repeated the above with 3 USB cables, all confirmed with other Feathers etc. put a USB hub in place etc

Ran through the trinketloader with 3 Mac's - 2 Arduino Unos Soldered a cable onto the reset pad, all with no luck.

trinket loader says"
Code: Select all | TOGGLE FULL SIZE
Trinket loader!

Type 'G' or hit BUTTON for next chip
Starting Program Mode [OK]

Reading signature:3D02
Searching for image...
 Not Found
Image fail



I have attached a battery - after fully charging it

I am at my wits end - my wife looks at me like I am crazy - I beg her to pull me away from this insanity.

PS I have 2 other Gemma's that also won't go into boot loader mode, but they have working neo pixel strings attached and working code - so I'm not messing with them.

Here is a picture of the connections - all have been continuity tested

IMG_1162.JPG
IMG_1162.JPG (348.61 KiB) Viewed 904 times

jwtadmin
 
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Re: Gemma bootloader - again

by adafruit_support_rick on Tue Apr 26, 2016 11:15 am

Connecting neopixels to 3.3V is not a good idea. That can overload the voltage regulator on the Gemma. you should power neopixels from Vout.

In your picture, I can't quite see exactly where the wires are connected to the UNO, but it doesn't look like you've got pins 10 and 12 connected? Should be:
Gemma GND pin to Arduino GND
Gemma RST to Arduino #10
Gemma #0 pin to Arduino #11
Gemma #1 pin to Arduino #12
Gemma #2 pin to Arduino #13

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Re: Gemma bootloader - again

by jwtadmin on Tue Apr 26, 2016 11:55 am

Thanks for the tip on the 3.3V - it's only 9 Pixels though.

The green wire in the photo is blocking the header view, sorry for the lousy shot.

The Gemma are indeed going to the correct Uno pins - re-verified 3 times - and continuity checked.

I can't see why I am having the problem with the boot loader. I was clearly able to get the loader to work before on 3 Gemma's including this one- wasn't always easy, but it worked.

Is there a possibility an OSX issue is preventing the loader from working?

jwtadmin
 
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Re: Gemma bootloader - again

by adafruit_support_rick on Wed Apr 27, 2016 10:40 am

The gemma works fine with OSX. Sometimes, though, they don't work well with USB3.0 ports. That's why we suggest using a USB2.0 hub. Sometimes, it's simply the USB cable. There are a lot of sleazy ones out there.


The 3.3V regulator only has a 150mA output capability. You could easily exceed that with 9 neopixels, depending on how you use them.

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Re: Gemma bootloader - again

by aloibaf on Wed Jan 11, 2017 12:58 pm

Hey guys,

I had the same problem with my Gemma:

jwtadmin wrote:Symptom - no pulsing LED

...

trinket loader says"
Code: Select all | TOGGLE FULL SIZE
Trin
ket loader!

Type 'G' or hit BUTTON for next chip
Starting Program Mode [OK]

Reading signature:3D02
Searching for image...
 Not Found
Image fail





I then solved it with the Arduino Uno 5V pin connected to the 3.3V pin of the gemma, the rest of the pins connected as described in the bootloader repairing tutorial mentioned above. I had to reset my Arduino several times and often got the same error as quoted, that was when I still had connected the 5V Arduino pin to the Vout pin of the gemma. But when I switched the circuit to the 3.3V pin of the gemma the error "Failed to verify fuses". I reset everything again and after a while it worked. I didn't have to solder a wire to the gemma reset button, holding an aligator clip worked for me.

That's not a good solution but at least there might be the possibility that it works after some retries :D

aloibaf
 
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Please be positive and constructive with your questions and comments.