DIY Night time Clock Projector | Superior Digital Initiatives
A Clock Projector can mission the time to a ceiling within the evening.
There are many business alarm clocks with built-in clock projector available on the market however I assumed, it might be enjoyable to construct one myself.
Furthermore it was a superb mission for changing into accustomed to the method of 3d-designing circumstances which might be 3d printed and to study designing tolerances.
The precept is simple – mainly it really works like a video beamer (or some other projecting clock^^).
LCD and Calculations
I choosed a small damaging (background black) 64×32 LCD which has the scale of simply 15mm x 12mm (lively space 11.18mm x 5.58mm).
The aim was to construct an entire projector with no more than 50mm x 50mm x 50mm (which I didn’t managed … However near^^).
A small LCD has the benefit that every part turns into smaller and cheaper – this influences closely prices for optics as a result of a smaller LCD wants smaller optics to mission an low distorted picture.
Furthermore a smaller LCD wants smaller focal size for a good sized imaged on the ceiling. A long way can be 2m from LCD to ceiling.
The system for picture width relying from the focal size is outlined as:
with:
– S2 distance from lens to LCD and
– S1 distance from lens to ceiling
– W2 is the width of the LCD
– W1 is the width of the projected picture
The formulation present that the smaller the focal size the bigger the projected picture will likely be.
I made a decision to go for 25mm as a result of there are low-cost lenses which might be obtained for about $12 in china.
For our values that will enlarge the picture by about x80 – 11.1mm LCD width would develop into 88.1cm picture width on the ceiling in a distance of 2m.
Mild and Condensor Lens
It was not likely clear how robust a LED must be to be able to get an inexpensive effectively readable image within the evening on the ceiling.
To make sure – really I wasn’t actually – I made a decision to make use of a excessive energy LED with 1W and use an affordable chinese language condensor lense to parallelize the sunshine earlier than it passes the LCD (this has do be achieved anyway however a condensor lens makes it doable to make use of extra gentle as a result of condensors are formed in a method that allowes to get the lens as close to to the LED as doable – so catching extra gentle).
The 2 photos present the condensor-lense which is instantly mounted to the PCB the ensuing gentle spot on the ceiling. It’s a actually gread lens which is made for my LED – so it suits completely and parallelizes the sunshine properly.
Electronics Building
Two PCBs have been designed – one holding the LCD and the precise projecting board.
The latter is supplied with 1W LED driver, STM32F103 Cortex ARM, a rotary encoder (for altering settings like brightness, standby-timer, time, …), USB, IR (each not used but).
Mechanics Building
Initially, I aimed for 50mm x 50mm x 50mm however I solely managed to get to 60mm x 60mm x 60mm 😥 😉
Right here an outline about all I designed:
From left to proper: Case with DIY projection lens (I skip this half – it labored however not likely effectively), Sony E-Mount, C-Mount. Within the center the remainder.
LCD-Holder
A customized LCD-holder was designed to completely mount the LCD on the best place on the PCB.
Case – C-Mount Variant
There are extremely low-cost chinase C-Mount lenses with a focal size of 25mm. They’re sooo low-cost that picture high quality is de facto actually unhealthy when utilizing for fotography.
However surprisingly it really works (nearly) good for the Mini DIY Projector 😀
The pillow-effect (optical distortion the place the perimeters are usually not straight however bent outwards) is nearly neglectable – ensuing a significantly better picture than I anticipated (after studying critiques to this lense)
Case – Sony E-Mount Variant
Only for enjoyable – and since I’ve a 3d printer which works reliably with out a lot consideration – I did a variant for Sony E-Mount.
Right here the projector with Walimex Professional 10mm 2.8 lens.
I’ve to confess – it isn’t that brilliant in actuality nevertheless it’s nonetheless very readable though it’s so giant.
The picture has greater than 2m in width! And distortions nearly non-existent 🙂
Downloads
Followig GitHub-Repository comprises:
– Schematic
– Format
– Invoice of fabric
– STM32 Cortex ARM Supply
– 3D-STL-Information
– Pictures