OK, the project is ready but there are some things I needed to point out:
3-Digit Countdown Circuit
As with most off-the-shelf circuits, they need to be modified. And so, after some tinkering, I got the counter to count down very fast but you have to watch the video to see the speed. Unfortunately, the Nokia 5800's video is not that good and so, in the video, the LEDs look very weird. However, to the human eye, they are perfect.
If, and if, for any reason the counting down is too fast, just locate the 555 time PCB (the smallest circuit board) and just cut off one of the leg of the paralleled resistor which has been soldered to resistor R5. This would slow down the counter and you will see the first two red LEDs blink slower.
Looking at the whole countdown circuit, I think it is possible to connect to another set of countdown module & 3-digit display. This would expand the whole thing to 6-digits. Ah, but there is a catch. The way the 3-digit circuit boards are designed, it is not possible to join them together to form a nice row of 6 digits but rather, a set of two 3-digits. But if you insist, it can be done but it would need a lot of re-wiring onto a stripboard.
Do bear in mind that the wiring is quite fragile and you have to be very careful with them. I will await your SMS for the greenlight to post before I hot glue the wiring. Also, days after I bought the whole thing, they came out with a 4-digit version but using a microprocessor. As it costs about RM4.00 at Rm72.00, I have no more funds for it. And since the kits have been soldered, it is highly unlikely that they would accept any trade-ins. Moreover, since I am not buying it, there is no way I could open the package to see if the assembly code (software) is in there or not. What it means that, if the chip burns, it would cost another RM72.00 to replace it instead of just buying the chip and programming it since there is no software to do so.
As requested, I tracked and bought a female to female USB converter but at the price of RM15.00 which I am sure is a bit steep. Maybe I can search for them in Low Yatt for Rm13.00 or so but I don't think they have any. And so, with the remaining funds until next month, this is the best I could do. I have modified only ONE LED badge as you mentioned there is a tight space near the collar bone, which I think, an unmodified LED badge with velcro would be the best solution.
What I did was to extend the three switches to a few inches longer and with a more user friendly buttons. You do need to charge them for two hours (with the display off) for a minimum of 12 hours of display. The sheet of A4 red filter would have enough to cover both the countdown and LED badges.
Some work in progress pictures.
Testing the down counter module which is soldered
to the 3-digit LED board at . Yeah, its a rip-off but
as mentioned, given the time-frame, thats the
problem with off the shelf solution. Testing the
connections but its hard to see the LEDs light up
since I am using low voltage. When it is OK, I
plugged in the ICs.
I got a simple LED flasher using a 555 timer
for this purpose. Modified the resistors to
give a very fast clock pulse. If you think its too
fast, just cut one of the legs of the resistor that I
soldered to resistor R5 in the 555 timer PCB
module. Also fixed a push button switch where
with a push, you can reset the countdown to
start back from '000'.
OK, everything is almost ready. You need to see
the video for the countdown's timing, if its the
kind of speed you are looking for. Of course
the 6-digits would countdown slower.
because I can only find one USB female2female
converter and got skinned at RM15.00. Due to
costs, I am only modifying one LED badge.