Ok guys, was away for a bit on family duties, here’s the final update before I put in the order within the next 2 days!
- I had @FantomXR change the LED Ring design to 32 instead of the prototypes 36 LEDs. That’s what I originally had planned too, for three reasons:
- easier mathematical mapping of n^2 values
- Better usage for rhythmic/timing use, ie. a 32 step circular sequencer (think Euclidean Circles module)
- More space between the LEDs for possible masking solutions. The diameter of the ring will remain the same at 33mm. At the classic 80% perimeter encoder use (as shown in the demo videos with the bottom 5 LEDs blacked out), you will now have a 27 LED resolution instead of 31 on the prototype.
- The LED cross bleed which I was worried about for a while should be no issue with this updated version. Even without any masking or light pipes it is not that bad as you can see on all the demo videos. With the new LED distance it is quite easy to mill or print a little plastic masking ring if you want. And simple light pipes, even just hand cut from optical fibre, improve the quality a lot too. I will post pictures and videos of my results soon, but probably not in time before the order.
- Added SMD solder point for an optional power supply capacitor at the power supply pins of each LED board.
- Using WS2812C 2020 LEDs for much lower power consumption than the B variant.
- Added some extra pinouts on the encoder board for more efficient use of the 74HC165: on the prototype each 165 was filled with the 6 pins of two switchable encoders, wasting the 2 remaining pins. Now all 8 pins of the 165 have unique TH-solder points so empty pins of the 165 can easily be used for additional buttons. Eg. You can now connect 2 switch-less encoders and 4 pushbuttons to the same 165, or 1 switchable encoder and 5 pushbuttons, twice that per encoder PCB.
- Added a TH-solder point for the 165 Clock Enable pins so the boards can be used with bitbanging protocols instead of SPI only.
- Unfortunately due to some family emergencies over the last weeks I was not able to finalize the design in time for the afore mentioned manufacturer discount. I still managed to get a decent offer, and so far group orders including my own demand are at around 160 sets. That gives the following prices:
- Net manufacturing cost per fully assembled PCB set: 19-21 EUR (depending on the final numbers)
- Import taxes (VAT of 19% for EU, tbd for US and other countries) around 4 EUR per set
- Individual shipping to you (tbc, but probably 5-10 EUR per shipment, depending on destination country what shipping insurance etc you want)
- That equals to a roughly estimated overall sum of 30 EUR for 1 set, 50 EUR for 2 sets, 90 EUR for 4 sets, 170 EUR for 8 sets. plus/minus 5% i guess.
- This isn’t cheap but I am 100% sure it still is really good value for what you get. It's around the same price you pay for one single ALPS rotary encoder with a single color LED ring.
- The price is for a set of two PCBs, one with 4 RGB LED rings, and one for 4 rotary encoders. All SMD parts and the assembly is included, the actual rotary encoders and any through-hole solder pins are not included. Might be able to supply standard Bourns PEC11L if needed.
- I personally pay about 7 EUR more than this for every set, in my personal development/protoyping costs. So if you feel generous and support the cause, the net price per board would be 25-26 instead of 19-21 if I distributed the dev costs equally.
- Order will be put in this week, production and shipping will take approx 2-3 weeks, and then another week for testing and further shipping on my side. Expect it in your mailbox end of july.
- Also I am talking to a very popular US based modular DIY supplier who will eventually stock some boards in his webshop. Will confirm asap, pricing tbd.
And a summation of what I think is important information:
This is a non commercial group buy of a pcb board. You buy the pcb board with all the SMD parts and assembly and nothing more. Of course I will take full personal responsibility in case something is fundamentally wrong or not working at all with the final product, based on a design mistake on my end. But other than that that’s all you get. No official support, no guarantees etc etc.
That being said: I designed these for the MIDIbox platform originally and I also successfully tested and use them on Arduino boards and the Axoloti platform. They work perfectly. I will write basic functions and objects for all these platforms over the course of the next weeks and of course I will share all these with everybody. Also basic general control for ws2812 LEDs and 74HC165 rotary encoders is readily available for all platforms already. I’ll also throw together some basic quick start guides and assist with connection set-up problems, but I expect anybody getting in on this order to be able to set up their own serial communication on the right pins of their respective controller boards. Expect a hardware protocol limit of around 500 LEDs (3-4 4xLED boards) per serial line if you want to maintain a 60Hz refresh rate, as with any WS2812 application. Also the obviously the more 74HC165 you chain in series, the higher the latency will get.
Both those programming libraries and the PCB design will be open sourced at some point. I don’t know when because I don’t want to do a half assed job on that and proper cleaning/optimizing and documentation might take a while.
You will have to buy and solder your own rotary encoders. The boards are designed for and tested with the Bourns PEC11 and PEC16 range, I personally recommend PEC11L low profile encoders. The optional LED board SMD power input cap would have to be self supplied and hand soldered too but in most cases will not be necessary.
So yeah that’s about it. If I didn’t scare you away by now, please RSVP as soon as possible. Either here via a private message or via email at rgbledring at gmail dot com, then we can exchange personals and discuss details.