LDR, photodiode or?

[throbscottle]

Yeah I know the feeling. Are you considering a rechargeable coin cell battery, this kind of thing: https://uk.rs-online.com/web/c/batt...able-batteries/button-rechargeable-batteries/ ? I didn't look at the mAH on them

 

[Nigel Goodwin]

Yeah I know the feeling. Are you considering a rechargeable coin cell battery, this kind of thing: https://uk.rs-online.com/web/c/batt...able-batteries/button-rechargeable-batteries/ ? I didn't look at the mAH on them

It's not a lot.

 

[Visitor]

A 2 × AA battery holder could be installed on the board, so people could use alkaline, non-rechargable lithium or rechargeable NiMH batteries.

 

[gophert]

Remember that the LDR will allow current to flow during the entire day.
Also, if room lights are on, will the lamp light? If the Christmas tree is in a room with the shades drawn during the day, will it be on or off?

I think a USB with a real-time clock and coin cell back up on the RTC would be just complicated enough to make the project fun.

 

[throbscottle]

Yay, go RTC! That would be sufficiently mad.

 

[MrDEB]

If I go with AA or AAA batteries then weight will be a factor if hanging from a tree branch instead of on top of the tree. On a branch would make turning it on/off easier and changing batteries.
LOTS to consider.
I like the AA or AAA battery power but the weight?
As far as the LDR, it would be set to come on in almost total darkness UNLESS a cheap, wireless setup could be achieved?
more research

 

[MrDEB]

Did some research and found a viable cheap method for remote control of Christmas star. Maybe program pic to change pattern with remote.

 

[Visitor]

You might use a random IR remote, acting on any signal received, to toggle the circuit on and off.

The wrench in the works is that to do more, like change patterns, you'd need to decode the IR signal and map buttons to different patterns. The big but is that every type of remote control sends different codes. Chances are a remote control a friend may have won't match whatever you've coded for.

 

[Nigel Goodwin]

Did some research and found a viable cheap method for remote control of Christmas star. Maybe program pic to change pattern with remote.
View attachment 126244

Why the transistor at all?, and why is it upside down? - also what's the 1uF for?.

Are you trying to detect 'any' IR signal, or actually read the signal in the PIC?.

It's also usually a good idea to decouple the supply to the TSOP, check my tutorial hardware.

 

[Pommie]

Why the transistor at all?, and why is it upside down?

Missed that. Whenever I've used an IR detector I've just connected out to the pic pin. There's also lots of sites that describe the IR signals.

Mike.

 

[MrDEB]

yes I located a schematic that does not use a transistor.
As for the output. Contemplating a counter. count = 1 turn on star
count=2 change pattern
etc.
yes it is maybe in need of a cd4017?
most any remote will work, just figuring out what key to press.
ordered some TSOP1738s and will breadboard etc.

 

[Pommie]

Yup, you need a counter to recognise IR codes. Go for it.

Mike.

 

[Visitor]

most any remote will work, just figuring out what key to press.

Most any remote remote should work ]i]for what[/i]???

Each remote uses a unique code, so pressing [1] on your remote will be a different code than your friend gets when he presses [1].

Your device could have a "learn" mode where it can be programed with codes from any remote, but that adds a lot of complexity to your code.

From a tutorial on decoding IR signals:

"This 32-bit number uniquely identifies the button that you pushed. If we push the Volume down and Volume up buttons on this remote we would get the values 0xFD00FF and 0xFD40BF."

 

[MrDEB]

to turn the star OFF/ON and maybe change patterns?
going to wait until I can breadboard and play with it.
was thinking of bread-boarding and using a tactile switch to emulate the TSOP 1738 input?
The capacitor is supposed to suppress the 38khz signal? as per reading about the circuit I posted.

 

[Visitor]

 

[Nigel Goodwin]

to turn the star OFF/ON and maybe change patterns?
going to wait until I can breadboard and play with it.
was thinking of bread-boarding and using a tactile switch to emulate the TSOP 1738 input?
The capacitor is supposed to suppress the 38khz signal? as per reading about the circuit I posted.

The 38KHz signal doesn't come out of the TSOP, which demodulates it and only provides the original modulation (or a rough approximation of it).

As you're feeding a PIC pin, why not just decode the modulation?, it will be MUCH more reliable, and then you can select different options using different keys.

 

[Visitor]

As you're feeding a PIC pin, why not just decode the modulation?, it will be MUCH more reliable, and then you can select different options using different keys.

MrDEB is planning on giving these Christmas ornaments to his friends, thus programming them to decode his own IR remots control is unlikely to work for anyone else. What are there, hundreds of different IR codes in use?

 

[Nigel Goodwin]

MrDEB is planning on giving these Christmas ornaments to his friends, thus programming them to decode his own IR remots control is unlikely to work for anyone else. What are there, hundreds of different IR codes in use?

That's why you provide the specific correct remote with the product - trying to detect 'any' IR modulated signal will mean that pressing any remote control will activate the light.

I'll just turn the TV volume up - oops - why has the xmas tree light come ON?.

 

[hexreader]

LDR was the simple solution that MrDEB might have had some hope of achieving with a moderate amount of help from forum members.

Why has this thread moved to domestic IR, which by MrDEB standards, becomes hopelessly complex.

MrDEB - Get simple LDR project working first - then move to IR remote control if you want a serious challenge.

... just my thoughts - ignore if you want

... oh - and do your friends, and yourself a favour, and use wall-wart or phone charger to save on battery costs. Also makes the project simpler as power consumption will not be a design issue. (hint - TSOP1738 uses quite a lot of power all by itself)

 

[Visitor]

That's why you provide the specific correct remote with the product - trying to detect 'any' IR modulated signal will mean that pressing any remote control will activate the light.

I'll just turn the TV volume up - oops - why has the xmas tree light come ON?.

Two points to make here:

1. MrDEB is trying to keep the cost low (think zero) and the idea is to use ANY remote. The idea of providing remotes has not been discussed here, and is counter to the zero cost idea.

2. I have commented SEVERAL TIMES that detecting ANY IR signal won't achieve MrDEB's stated goal of selecting between different programs.