Dome Nodes - v2

Projects
1

EMF was announced for next year :slight_smile:

I plan to improve on the DomeNode hardware after what we learnt previously.
Here’s what I have so far:

  • 24v-5v regulator is not precise enough. We should add a separate 5v LDO regulator alongside the 3.3v one to power sensitive devices (e.g. the neopixels).
  • Neopixels should be put on a separate ‘shield’. This would simplify construction dramatically, as these basic shields could easily be stenciled/reflowed. It also means testing will be easier as we separate the various functions.
  • Vertical RJ45s :slight_smile:
  • Potentially additional functionality testing. I populated the original board with microphone and speaker options, but it’s feasible we could shield these as well and do something more fun with them.
  • Also possibly allow fitting of a dev board instead of ESP module for easier soldering/development.
  • Easier programming, specifically using the special ESP programmer with built in reset/program ability.
2

I should also mention I was very pleased with some of the specific successes we had:

  • Speed of setup was quite impressive
  • The touch plate mounting holes on the PCB for the capacitive sensing worked really well (and I am quite pleased with their design)
  • We turned the design/manfacture of the boards around super quickly.
3

It also occurs to me that we could simply use some off-the-shelf neopixel ‘rings’ instead, or, the power RGB LED :slight_smile:

7

Looks like the project is coming on a treat !

8

I’ve been having a good think about the firmware and overall architecture for DomeNode v2. Hopefully, I’ll be getting started on it soon.

I have a small side project of a music visualiser that I’ve started to work on - I’m hoping it will provide a slightly simpler entry into the complexity of the DomeNode solution as a whole.

My thoughts, so far:

  • We should have a router in the space as part of the setup that all of the nodes are connected to. I will provide one. This can then be taken to wherever the dome is set up.
  • This router should also be accompanied by some sort of central server, e.g. a raspberry pi. This pi will provide several features:
  • A central firmware update repository for automatic OTA updates
  • An MQTT server that the nodes can communicate to, for a central logging solution (for easier debugging and monitoring). I choose MQTT because I already have experience with it and embedded ESP32 devices. We could also use something like rsyslog.
  • Some sort of central control (someday!)

I have recently discovered ArtNet and will be experimenting with this. It’s essentially a way to configure a lighting ‘fixture’ and control multiple fixtures from a central point. The particulars of a light show are defined by a compatible lighting design software, of which several I’ve seen are open source.

9

Resurrecting DomeNodes!
I am planning to work on these in the near future (tying in with a fun to-be-announced modular synth project).

The main reservation about the current hardware is the power regulator for 5V. I’ve thought of a way we can address this, without changing the hardware of the current boards.

I also found that ESP32 OTA updates are now easily supported in MicroPython: https://github.com/rdehuyss/micropython-ota-updater

10

For the 5v supply either cascade the switched mode module with a fixed voltage regulator (mainly to relieve the voltage stresses across themselves and it’s what PC’S do) or use the HVT suffixed switched mode regulator s straight. Have purchased both fixed (5v) and variable HVT suffixed regulators from Farnell. As implied with other replies larger heatsinks may be required if a single stage regulator module is chosen. With that/a mammoth 200W 0-15v,0-15v series connected transformer a peak voltage of 40v dc maybe seen when rectifyed and smoothed. See Velleman website where a link to ON Semiconductor can be followed. There you’ll find a pcb layout that uses through-hole components and larger cool rail vertical heatsinks. Suggest 50 mm high which could be found at Rapid Electronics if I haven’t already brought to the Boiler Room and in the Dome Node and my box. Current limiting- as there are 3 +3 cores used on the CANBUS system suggest a limit of 800mA to 1A per core. The switched mode modules will put out 2.5 to 3A. A current boosted linear 24v regulator uses a 0.22R to 0.27R resistor on the booster transistor’s emitter to limit the maximum current to around 3A. As an absolute measure a delay fuse fitted to the transformer’s output lead may suffice (3.15A). There’s a tapped 100VA transformer on Jaycar’s website. It has 2 × 12/15V windings. A discouraging factor in purchasing this is coming from Australia and an extra hidden cost is customs charges.

11

Just adding to the trail here for mine and @AndrewPatience’s benefit, ESP32 CAN bus support in micropython is coming as per this Git issue: https://github.com/micropython/micropython/issues/5087#issuecomment-538779410

There is already a beta package built, so shouldn’t be too long before we can get this implemented easily.

12

Got spare HVT switching regulator ic’s for psu and heavy duty inductors. Due to lack of personal transport to other places other than the Boiler Room I would like to arrange for someone to pickup these components from my home.