I have 3 gemma's (two adafruit and one arduino) that I can't seem to get into bootloader mode. I have tried 3 usb micro cables and both ports on my MacBook Pro (all of which function normally with other hardware) but still when I press the reset button the red light illuminates solid for ~3 seconds and then turns off without strobing. Attempting to load any code through IDE returns the "Could not find USBtiny device (0x1781/0xc9f)" error.
I couldn't find any previous threads relating to this, but if you know of one please link me :)
Gemma won't enter bootloader mode
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Please be positive and constructive with your questions and comments.
- adafruit_support_mike
- Posts: 67485
- Joined: Thu Feb 11, 2010 2:51 pm
Re: Gemma won't enter bootloader mode
Try re-flashing the bootloader: https://learn.adafruit.com/introducing- ... bootloader
The tutorial is for the Trinket, but the Gemma uses the same microcontroller and firmware.
The tutorial is for the Trinket, but the Gemma uses the same microcontroller and firmware.
- absurdstarfish
- Posts: 2
- Joined: Sat Aug 01, 2015 11:16 am
Re: Gemma won't enter bootloader mode
Decided to try one more cable before I went through the trouble of flashing the bootloader, turns out that was the problem.
- adamjdanger
- Posts: 3
- Joined: Thu Jul 28, 2016 1:10 am
Re: Gemma won't enter bootloader mode
I had a similar problem on a macbook pro and solved it but plugging the gemma into a usb hub rather than straight into the mac's usb port.
- socrates6
- Posts: 7
- Joined: Sun May 15, 2011 6:32 pm
Re: Gemma won't enter bootloader mode
I have the same problem. When I push reset on the gemma the LED goes through a rainbow of colors. Im assuming that isnt bootloader mode.
- adafruit_support_mike
- Posts: 67485
- Joined: Thu Feb 11, 2010 2:51 pm
Re: Gemma won't enter bootloader mode
Verify your USB cable by using it to connect some other, known-working device to the computer.
There's a plague of charge-only cables out there with USB connectors at both ends but no wires for the data signals. We see people get caught by them every day.
There's a plague of charge-only cables out there with USB connectors at both ends but no wires for the data signals. We see people get caught by them every day.
- socrates6
- Posts: 7
- Joined: Sun May 15, 2011 6:32 pm
Re: Gemma won't enter bootloader mode
Yeah, the cable works for the trinket.
- adafruit_support_mike
- Posts: 67485
- Joined: Thu Feb 11, 2010 2:51 pm
Re: Gemma won't enter bootloader mode
What do you see in the Device Manager or System Information USB pane when the Gemma is connected to the computer?
- tkwanjp
- Posts: 2
- Joined: Thu Dec 13, 2018 11:40 am
Re: Gemma won't enter bootloader mode
I'm in the same situation.
I just got a new Gemma v2, have 4 cables.
Tried
cable 1, failed. Green LED lit but not for red LED.
cable 2, succeeded! Red LED also blinked fast.
So I uploaded a sketch. Then tried uploading another sketch, failed back to the same situation.
Tried
cable 3, failed.
cable 4, succeeded! Red LED also blinked fast.
So I uploaded a sketch. Then tried uploading another sketch, failed back to the same situation.
(tried all combination of cables 1-4.)
What can I do?
I just got a new Gemma v2, have 4 cables.
Tried
cable 1, failed. Green LED lit but not for red LED.
cable 2, succeeded! Red LED also blinked fast.
So I uploaded a sketch. Then tried uploading another sketch, failed back to the same situation.
Tried
cable 3, failed.
cable 4, succeeded! Red LED also blinked fast.
So I uploaded a sketch. Then tried uploading another sketch, failed back to the same situation.
(tried all combination of cables 1-4.)
What can I do?
- adafruit_support_mike
- Posts: 67485
- Joined: Thu Feb 11, 2010 2:51 pm
Re: Gemma won't enter bootloader mode
@tkwanjp: Please start a new thread for your issue.
- tkwanjp
- Posts: 2
- Joined: Thu Dec 13, 2018 11:40 am
Re: Gemma won't enter bootloader mode
@adafruit_support_mike essentially my problem is just as same as here; won't enter boot loader mode.
I've replaced the previous Gemma to a new one, but it still don't enter boot loader mode.
connect Gemma to the computer, green LED lit. Push the button on the Gemma, red LED lit for a couple of second then turns down.
Upload sketch, get an error:
"avrdude: Error: Could not find USBtiny device (0x1781/0xc9f)".
Using Adafruit Gemma (with a black PCB board). Got through the instruction of [Setting up with Arduino IDE https://learn.adafruit.com/introducing- ... rduino-ide].
I've replaced the previous Gemma to a new one, but it still don't enter boot loader mode.
connect Gemma to the computer, green LED lit. Push the button on the Gemma, red LED lit for a couple of second then turns down.
Upload sketch, get an error:
"avrdude: Error: Could not find USBtiny device (0x1781/0xc9f)".
Using Adafruit Gemma (with a black PCB board). Got through the instruction of [Setting up with Arduino IDE https://learn.adafruit.com/introducing- ... rduino-ide].
Please be positive and constructive with your questions and comments.