Unable to change Mode on photon

Can you video the led light sequence?

What happens if you hold the SETUP button continuously… Does it end up blinking blue?

It never ends up blinking blue. Sometimes it might blink blue for a second or less and then goes back to this green state as in the beginning and end of the video. I will try to re-create the conditions under which it blinks to another color for an instant.

Here is the video. Sorry for the bad resolution
UPDATE: Here I got it to blink the other colors but only momentarily.

Tip: Dont know why but to see the video you need to refresh the web page and then the video plays fine.

@Particle_Null, this is weird. Never encountered this before. What was the Photon doing before it entered this state?

Well I connected it to a wifi network and did the initial setup with the particle android app. Then it was showing the name of the photon as photon-hamster and since I do not like hamsters at all I renamed it to something else. After that I could not connect to the photon with the android app anymore so I selected the unclaim device to see if I could connect to the device with the new name. Thats when I realized the photon was locked in this weird state. Any suggestions on what I should do ? Can it be repaired or do I simply return it ?

Can you remember how you named it?
Just to try if we can kill more Photons with that name (might be an “easter egg” :wink: )

Cant remember it clearly. It was photon-something. photon-cadet or photon-commando something. Like I said I was just trying things out so I gave it some silly name. Is it possible to get that information from my particle account ?

Drop the support team a message here to see if a replacement can be done: https://docs.particle.io/support/troubleshooting/common-issues/electron/

Well I bought it through a third party so I do not think filling out this form will be helpful.

Should not it be possible to reprogram the device with a JTAG programmer ?

It is possible if you have a JTAG programmer. Whether you bought the photon from a third party of not, you can still contact :particle: support.

You can request from them the factory binary used to flash on new Photons and the instruction to do so using a JTAG programmer.

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Thanks I sent them an email

If you have a 2nd device, such as a core or another photon, you can use that as a programmer too. Reprogramming the bootloader with the latest one should get you out of this - it sounds like the DCT corruption bug that was in the first run of photons.

Sorry you’ve been bitten by this and thanks for your patience in answering questions to get this resolved.

This repo https://github.com/m-mcgowan/embedded-swd shows how you can use one device to program another. The instructions are work in progress - if they’re not clear I’m happy to help you through the process.


Hi. Could you help me with the “Using programmer App” part.

How do I Open a serial terminal to the device.

You can use a software like CoolTerm or Putty

I am using putty on linux. I ued the particle serial list to confirm that my device is connected to /dev/tty/ACM0. But putty gives a message saying unable to connect to device. I used the settings on github namely

  • Baudrate: 9600 Data Bits: 8 Parity: none Stop Bits: 1

There i also a flow control option but I leave it a it is : XON/XOFF

When I click on run it says
unable to open connection to:
unable to open serial port

ok do not know why but putty does not work properly on ubuntu. I switched to a windows PC and it works fine. Now I get this error after the " Do you have a dead device and wish to continue ?" msg
Unknown ACK(5) received. Please Double check the wiring then try again. And yeah I did double check the wiring.
PS: I am using a 12K resistor instead of 10K since I do not have one on me right now

I saw that error during development. It’s indicative of a missing GND connection. Double check that you have both GND connections in place.

I checked and double checked both GND connections on both devices. They seem to be working properly. Also should we continue this discussion here in the community forum or on the github repo ?

The problem is electrical - I was bitten by this for hours until I connected both GND connections. You might also try with a 10k resistor, since that’s what specified.

I think one of the connectors that I was using before was faulty. I used a new set of connectors and now I get this error

warning: unexpected idcode: fe7e033f
SWD Protocol error

PS: Using 10k or 12k resistors does not seem to make a difference

8 posts were merged into an existing topic: Photon Solid Red LED?