BigBit Binary Clock Display
In a previous Instructable (Microbit Binary Clock), the project was ideal as a portable desktop appliance as the display was quite small.
It therefore seemed appropriate that the next version should be a mantel or wall mounted version but much bigger.
There would be no need to reconstruct another controller but to use the existing clock and add an interface for the display.
This Instructable details the process of creating the BigBit display and the software updates to the existing clock.
Supplies
Black Perspex Sheet 21.5cm x 21.5cm x 5mm
3D Printer for plaques & nut holder (optional), as these could be created by other means.
M2.5 washers * 13 qty
WS2812 Neopixel Button LED's * 25 qty.
Enamelled Copper Wire 21 AWG or other insulated wire.
2mm drill bit
2.5mm drill bit
8mm drill bit
30mm Forstner drill bit
Design
The design would be modelled on the existing Microbit display using Neopixel LED's serially connected and arranged in a 5 x 5 matrix.
Labels would be included to identify Hour, Minutes, Binary weighting and Status indicators.
These labels would be created as 3 plaques, that will be 3D printed and inlaid with coloured resin fixed with screws, allowing customisation as required.
The main time display area would have lenses fitted to accentuate each time bit and improve angular viewing.
Rather than creating a project from the ground up, the previously created Microbit Binary Clock will be used to drive the display.
This required an update to the existing software to incorporate the Neopixel extension and coding to replicate the display functionality on the Microbit display.
Capability to wall or mantel/table mount.
Software
The software is based on the previous Microbit Binary Clock with additions for the Neopixel LED's.
Downloads
Main Panel
The main panel would be made from black Perspex of 21.5cm x 21.5cmm x 5mm.
Into this would be drilled holes for the Neopixel LED's and the recesses for the lenses.
The display matrix area occupies and area of 18cm x 18cm from the top right with the LED's space at 35mm
The recesses for the lenses would be 3cm in diameter by 1mm in depth.
The Perspex main panel was cut from a larger piece then the centres for the pilot holes marked on the protective paper.
Hole centres marked these were than drilled with a 2mm bit.
These were than used to align the 30mm Forstner drill bit which was used to cut the recesses for the lenses.
During the process of drilling the recesses for the lenses a warp began to develop in the panel due to the front to back temperature differential.
However, this was not a show stopper just on minor hiccup along the way.
In order to remove the warp it required placing the panel into a preheated oven at 80 degrees C for1Hr.
It was placed on a flat metal tray with baking sheets on the front and back faces to prevent the likelihood of sticking.
A metal tray was placed on the top and a weight applied to this.
After the hour the oven was turned off and it was left cool to room temperature.
The centre holes where then cut from the back with a stepped drill for an 8mm centre hole with a 10mm countersink, this is were the LED's would sit.
Plaques
While the Main panel was being drilled the Label plaques were being printed.
These were designed using BlocksCAD
Two of the plaques (Binary Weighting & Time Units), would have recessed text to allow coloured resin infill.
Whilst the remaining Status plaque would have open lettering to allow light to pass through.
The Binary Weighting and Status plaques would be mounted vertically, Weighting on the left and Status on the right.
The Time units would be mounted horizontally along the bottom.
All plaques would be orientated so that the text aligns with its designated row/column.
Once printed an resin infill was applied to the Weighting and Time units plaques.
Downloads
Fitting the LED's
The LED's would be joined together in a string of 5 each individually soldered to its neighbour by 3 wires of 21 AWG enamelled copper wire then each group of 5 would then be joined together with a jumper.
Each LED was spaced to sit in to the previously drilled cavity.
Each group of 5 LED's would be tested with the previous Instructable Neopixel Tester.
Once 5 x 5 groups of LED's are completed they are jointed together and tested with the Neopixel Tester.
The LED's were secured to the main panel with hot glue.
Lenses
The hemispherical lenses were made from a 2 part clear epoxy mix.
This was poured into 28mm diameter silicone moulds and allowed to cure for 12hrs.
Once cured they were popped out of the moulds and the back flat base was ground with sanding paper then the back was cleaned with wipe of Methylated Spirit to remove grease and grit.
The recessed were cleaned with Methylated Spirit and a toothbrush.
Once dry, each lens was glued into the recesses
The plaques at this stage were positioned for hole marking prior to drilling.
Neopixel Connections
The RTC used in the previous Microbit Clock required the addition of pin headers on +3V and GND and a connection to P0.
These were then connected to the Capacitor (1000uF/6V3 min), Resistor (470R), circuit mounted on the stripboard which is connected between the RTC and the BigBit Display.
Time to Show
The BigBit Binary clock can be hung by attaching ring terminals to the top screws and fitting a wire or string between the two or by the fitting of a concealed bracket which can be used for both hanging or standing.
The concealed bracket is formed from a length of aluminium that is bent to shape and drilled with both an M2.5 (attaching to the panel) and M5 (to attach the stand) holes.
Behind the bracket a 3D printed nut holder is fitted which both holds the nut and prevents it spinning behind the bracket. Into the nut in the bracket is screwed a threaded rod or bolt which acts as a stand.
Downloads
Finally
From an appropriate power source insert the USB connector into the Microbit or the RTC and set the time.
Your work is done, time to admire your work.