Hi all!
I received a lovely little box this week — the first v1 prototype of the fence PCB. It wasn't smooth sailing. I paid to have all of the SMD components soldered at the factory, but in the design phase I overlooked the need for a cutout for the USB-C port, so the one I specified in the design didn't fit. Essentially, the pins for power and data don't actually touch the PCB. We tried a couple of alternatives, but they were all the same. So I decided to source some top-mount options locally.
The first v1 prototype — fresh out of the box
This means that I currently have no way to flash the firmware to the ESP32 until they arrive. Luckily I have an ESP32 development board flasher from an old project, so I was able to heat up the heat plate, de-solder the ESP, flash it, and re-solder it back to the board. This is what I did, and powered up the first board. There were no explosions, so the 48V to 3.3V circuit worked correctly, and the LED indicator came on and connected to the Digifence server.
After running a homing test, it disconnected from the server. There was a lot of trial and error following this, which highlighted two more oversights. The first was a simple fix — I forgot to include a resistor that pulls the EN pin on the ESP high, so I soldered one on directly, and it booted stably. The second oversight was not excluding the ground plane behind the antenna of the ESP. So the ESP boots stably, but depending on the amount of interference, won't connect to the WiFi because the signal is too dirty.
A closer look at the v1 board
The fix is straightforward — I've ordered some ESP32s with external antennas. Moving forward this will be the module I use, and the antenna can be fixed to the enclosure, so it's actually a better solution overall. These boards will be the ones I use to develop the physical fence systems, so I'm not too worried. It's in the prototype phase after all and not the end of the world. I've already updated the PCB designs so they are ready to go once I'm happy and ready to push the order button.
A short one this week — work has been busy and I'm now approaching the stage of needing the workshop back.
Thanks again, and if you want to chat directly about anything, feel free to join the Discord.
Love you, bye
Tom