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Topic: Arduino WordClock (Read 19449 times) previous topic - next topic

Riva


I didn't catch this until today. Awesome! Definitely a huge step up from the original word clock, especially with the scrolling text thing!

The first version without scrolling was programmed into a ATmega8 and had about 68 bytes of flash free so I un-soldered the chip and replaced with a 328 to give the extra space to do scrolling. Apart from scrolling the date on request and temperature every x minutes (x because I have altered the code since posting) it also has programmed dates you can scroll custom messages for. I have family birthdays, anniversary's, Christmas day & new years day that scroll every 15 minutes on the programmed day.

liudr

This is a very neat piece of electronics. You should think about selling kits. Besides regular schedules, you can program in random jokes or "Arduino rocks" or else to go off.

DillyDog

Thank you Riva, didn't notice! I'm working on a small desk clock, only 150mm square, and I think your code is the best I've seen!

Riva


Thank you Riva, didn't notice! I'm working on a small desk clock, only 150mm square, and I think your code is the best I've seen!

Thanks, it was the first arduino project so coding may be a bit poor to seasoned C++ programmers but it works. Have fun building it, I did.
The overall size apart from the frame is 200mm square but I do have a large(ish) border around the LED's so the design would probably fit in 150mm square. Because I built the electronics on proto board that limits the size options as your limited to the 2.54mm hole grid. A custom PCB would be nice as you can size as needed. I am also considering using 4x led matrix blocks to build another one but it's hard to find a cheap 8x8 led matrix that uses white LED's, most all are red or green.

DillyDog

Let me know if you find white ones. I've been using  smd ones but it's very time consuming and fiddly soldering them by hand.


Stijn

Hey

Great work! I was more or less inspired by this post and by seeing one for real and started doing it myself as well. All is ready now but I'm facing serieus issues with the light: when using a sticker with a transparante background (so the letters are transparent) than the light is to strong and to much in one bundle (not enough spread) so you can't see the letters any more. Using a sticker with a white background makes it not transparent enough and my leds are almost not getting through... you only see it lighting up a bit... any hints how you handles this part?

Thanks!

Riva


All is ready now but I'm facing serieus issues with the light: when using a sticker with a transparante background (so the letters are transparent) than the light is to strong and to much in one bundle (not enough spread) so you can't see the letters any more. Using a sticker with a white background makes it not transparent enough and my leds are almost not getting through... you only see it lighting up a bit... any hints how you handles this part?


Hi Stijn,
Glad I could inspire someone  :D
After thinking of lots of possible ways to create the letter mask ranging from etching a copper clad PCB, printing on acetate, cutting letters out of sticky back plastic  and getting them laser cut out of card/plastic sheet I settled on a simple and cheap option of using a laser printer to print a reversed negative image on ordinary white printer paper. This piece of paper is cut to size then sandwiched between 2 bits of perspex. One is 3mm thick tinted that you lay the unprinted side of the paper on. Then you lay a 2mm thick clear sheet on top and tape/glue around the edges to keep it all together. I used a 2mm clear sheet because I had roughly calculated the light cone of the LED's would be the right size to illuminate the size of character printed on the paper when it's 2mm away without to much bleed into adjoining characters. This sort of worked when the display was dim but when it was bright I still got some bleed and had to resort to gluing black plastic straws between LED's. By luck more than judgement the printed paper worked very well and I did not have to bother messing around with different weight paper to get the desired effect.
You could try putting a ordinary bit of printer paper behind your transparency and see if it helps.

Stijn

Hey thanks for the fast response!

I started off with ordering venyl stickers which is rather expensive to 'test' so I feel stuck after ordering a few of them... the next one should be the right one. I'm working on a 50x50cm.

Here you can see the results so far:

Using a transparent sticker:


And a non transparent one:


I tried black 'light' paper between it, I tried white paper, I tried normal white paper, I tried so many things :) nothing works so far...

Riva

I must have been very lucky the first (and only) thing I tried worked for me.
Are you using MAX7219 chips or multiplexing with shift registers and are the LED's 5mm? I used 5mm high brightness white LED's and a couple of MAX7219 chips to keep the brightness up as multiplexing tends to dim the LED's.

Stijn

I'm using 2 MAX7221 chips, they work great. Apart from that also 5mm high brightness leds, but just using 2 MAX7221s, they don't dim that much... just have to figure out a better solution...

Beta1977

Hiya

where did you get the big stripboard plates ?

Riva


where did you get the big stripboard plates ?

It was hard to find a suitable large stripboard but I got it from here http://uk.farnell.com/vero/01-0042/veroboard-179-07x454-66mm/dp/1536942?Ntt=stripboard enough to make 2x clock (that I did)

liudr

The led looks a bit focused. Did you get the diffuse LEDs or not? Diffuse leds can be viewed from a large range of angles. Their plastic housings look rougher than a smooth plastic surface.

Riva


The led looks a bit focused. Did you get the diffuse LEDs or not? Diffuse leds can be viewed from a large range of angles. Their plastic housings look rougher than a smooth plastic surface.

If this question is directed at me then no I did not use diffused LED's. I used these http://uk.mouser.com/ProductDetail/Cree-Inc/C535A-WJN-CS0V0151/?qs=%2fha2pyFadugYYN%2fkEaGd5KoOjGvMC7QxGs05ryBegjRuYV232%2fuYlWKl%252b6XNvG2l to get the desired light cone diameter 1.6mm-2mm above the lens.

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