I have the PCB working now, and putting the photon/electron back on the breadboard also worked. I have an entirely different issue now and that’s neither of the photons will connect to WiFi. Although the Electrons work fine over 2G.
I gave up trying to set new keys on the Photon that was blinking blue yesterday and switched to another. Now this one is blinking blue and I haven’t changed anything since last night.
WiFi and cloud is working because the other 3 Photons I already have setup and working in other projects are woking fine.
It only started flashing blue once yesterday so I just swapped it out for a different photon and carried on. Now this morning that one has started flashing blue.
After they flash blue, I tried re-adding them via the android app which stopped them flashing blue they now flash cyan, then 1 red. They won’t go back to flashing blue unless I put them in listening mode. I’ve tried a full factory reset and re-add but still just flashing cyan then 1 red.
Tried to re-add the keys but ran into the issue above.
So now I have both Photons working by updating the keys. BTW this has nothing to do with the PCB I’ve been doing all this with the Photon disconnected from everything.
I thought I’d try out the electron as that’s the ultimate goal for the PCB anyway. However, I now have the same issue with that.
So I’m trying to update the keys on that too except now I have another issue.
If I put the Electron into DFU mode it freezes when I connect the USB cable. Or if I try and put it in DFU when already connected the LED flashes orange once and stops.
I’m not trying to do anything clever here, just drive a TFT breakout with a photon/electron. I’ve not even got to writing any code yet I just spend all my time debugging connection and cloud issues.
In searching for answers I’ve found similar posts of other people having endless connection/key issues. I know they can all be solved but I just don’t get why it feels so flakey.
Also, lets say I get it all working and it stays working long enough to develop the solution. I then package it up and put it into use and one of the keys mysteriously gets corrupted. I’m going to have to recover the device, open it up, plug in the USB, reflash it etc etc.
I’ve already invested loads of time into Particle, I’ve been using Cores since the very first shipment and I really want it to work but I’m honestly at my whit’s end.
If you place the Photon in the breadboard without any external connection, powered by microUSB, with tinker firmware, and the blinking blue issue persist then there’s definitely some issue with the hardware itself.
If the issue is persistent whenever a Photon is attached to your PCB while not having issue on a breadboard, there’s something to examine on the PCB side.
I would say that looking at the charging coil and it’s proximity to the photon/electron, I will not be surprised if you end up with some wireless connectivity issue + EMC/EMI complication.
It also looks like the ground plane is filling up the entire PCB (at least that’s what i guessed from looking at a picture and not the gerber). That’s definitely going to introduce connectivity related problems.
This is all with them in breadboards. They haven't blinked blue again unless I put them in listening mode. However, I can't get either photo to reliably connect now. If I run key doctor or play around with keys I occasionally get a connection, but once I reset it's back to cyan/orange. One of them has also disappeared from my list of devices but I can't add it back via CLI or web IDE as it says a device by that ID already exists. Bizarrely the second electron which I had working won't connect now but the first (faulty) electron does seem to connect OK, although that has now stopped working again.
The issue of SPI not working if I have the resistive panel connected at boot seems to have been resolved by setting the system to threaded mode. I decided to do this so I could carry on debugging the PCB without a cloud connection and now it just works 100% of the time.
I haven't added the charging coil yet, I just want to get it working 1 step at a time.
Can you explain, please? I'm no expert and this is my first PCB design. I thought the point of the ground shield was to fill up all the unused space on the PCB to a) provide a shield against EMI and b) make PCB production easier/cheaper. I've got all the GNDs tied to that shield but obviously nothing else.
The on-board antenna on a Photon needs clear space around it on the top and bottom in order to function properly. You should not have copper under the antenna portion of the Photon on your board. There is a clear keep out area on the Photon datasheet that shows this:
Ah, that makes sense. As it happens after the Photons started working again (I changed nothing they just started working after being left alone for a few hrs) I did try them in the PCB and they worked fine. I do have them on headers though so they are 10mm or so above the board. I've got an electron soldered directly but of course it has an external ant.
I'll update the PCB and leave some space clear as per the data sheet. Thanks!
EDIT - Just realised this is irrelevant as the photon will be sandwiched between the PCB and TFT breakout anyway so it will require an external ant as per the Electron regardless of the PCB design.
I’ve been working on quite an involved build this last week on both Photn and Electron and I’ve started to see a pattern forming.
The issues I’m having mainly seem to be cloud connection issues, not WiFi / cellular. The project I’m working on has a tft screen that shows the RSSI, cloud connection status and system events, in realtime, so it’s quite easy to get a fell for what’s going on.
At the start of the day everything works fine, devices respond and I can flash via the cloud (using Atom). After reset, they take a second or 2 to reconnect. Even the Electron after it’s initial cold boot is really fast.
Then after a few hours and many OTA and USB flashes and many resets, all the devices start having cloud connection issues. And that’s it I won’t get another successful connection until I leave everything alone for a few hrs.
In the past, this was a massive pain, but now I’m using system thread mode so I can carry on developing offline. However, it doesn’t solve the issue.
It’s like there’s some kind of rate limiting being applied, or my account/cloud connection just goes into meltdown after an hour of flashing.
Can anyone suggest a solution, I’m heavily invested in this project now and I’ve sidestepped the issues for development, but once it’s finished the issue will need resolving.