I like your idea of using IR, but there are still questions I have yet to find the answers too (probably because it's such an odd question to ask). How am I going to get the IR signal to "stop" at the range I want?
now this is something I cannot help you with, nor probably anyone else on the forum .. you will have to decide that for yourself. I have no idea how "expensive" the resin is, but you can try out different shell's .. maybe you can use some "old" props made out of different types of resin to test the "IR transparency" thing ..I think the main question besides that is the resin. I'll be honest at this point and say I'm not entirely sure which resin I'll be using. While I have worked with resins a lot in the past, the way to get clear resin to look like Amber is to mix in fillers. These fillers can range from shredded cloth, to dirt, to gold flakes.
well, it is fairly simple to test - of course, like with the IR, you need to decide on the shell material first in order to make successful tests. To play with US a oscilloscope would be useful btw.As for the US, I was kinda convinced of the same thing. I mean, I can stick my head in a bucket and people can still hear me even if it is muffled. I just don't know if the sound waves will "distort" too much through the resin. They might "hear" each other, but covering your mouth with your hand and singing aren't exactly the same when trying to get a message across.
All I can say is - have you ever saw US image of baby? Ok, that is more sophisticated device, but, that is sound .. and it travels trough the flesh&bone .. and then bounce back to be detected ... I'd say you have pretty good chance of transmitting readable signal trough resin with 40KHz carrier ..I don't know sound all that well (aside from basic knowledge), but if the waves are changed too much by the resin then it wouldn't really matter if it went the 30 cm or so because the receiver would be hearing a "muffled hand", no?
again, it is you who need to decide how the thing will look, how the resin will be shaped, with what it will be mixed etc... if you can make inside cast as well as the outer cast I assume you can make "budges" on the inside cast where your receivers and transmitters will be .. but again .. without making a choice and doing some tests, we exosted the theory here ... you have 2 relatively simple solutions (IR/US) that might work but might not, to know, you have to test ... it is fairly easy and fearly cheap... If that does not work you need to go the EM/RF field .. that's where I cannot go with you as I suck in those areas .. (not that I'm too good with digital tooI have been trying to see if there is a way I can adjust the resin so it has thinner parts. If you look on the other post on the main forum site, I posted some images of the stones from the movie. You can see how they have a darker bottom where the light doesn't quite get too...this is basically where all my hopes lay of hiding the internal components.
that I do not present a big problem ... the LED's will not be visible trough resin, the tranducers (if you go with US) are also quite small ... and the PCB/Battery you can put all way down .. so "hiding it" will not be a problem, and, you can make the bottom bit thicker/with more filler .. I have no experience with resin, but I'm pretty sure it can be doneThe ultimate trick in this whole thing is to not give away the "magic" inside. That means that the resin has to be thick enough to not allow the shadows of the components to be obvious, or they need to be pushed down to the bottom so far that it just blends with the already dimmer bottom.
no need to .. if you put few IR LED's and few IR receivers on the inside of the resin, they are not going to be easy to spot ... and some thin wires to the board on the bottom will solve the problemIf I could make the IR/US/RF signals radiate from the bottom, then I can perhaps place the closer to the surface without them being too obvious...this may help things.
Lets see about IR as well then. (I'm going to keep researching all three to be sure).
If anyone has any good, simple, working IR transmitter/receiver schematics (or where I can find some), that would be great. As well, does anyone know how to solve the distance issue?
Device = 18F2550
Clock = 8
Config FOSC = INTOSCIO_EC
Include "INTOSC8.bas"
Include "pwm.bas"
Include "IR_UART.bas"
Include "convert.bas"
Dim Variable As Byte
// start of main program
PWM.SetFreq(38000, 50)
IR_UART.SetTX(PORTC.2)
IR_UART.SetMode(umTrue)
IR_UART.SetBaudrate(sbr300)
Variable = 0
Low(PORTC.0)
While True
Inc(Variable)
IR_UART.Write(Variable)
DelayMS(500)
Wend
Device = 18F2550
Clock = 8
Config FOSC = INTOSCIO_EC
#option LCD_DATA = PORTB.4
#option LCD_RS = PORTB.0
#option LCD_EN = PORTB.1
Include "INTOSC8.bas"
Include "pwm.bas"
Include "IR_UART.bas"
Include "convert.bas"
Include "lcd.bas"
Dim Variable As Byte
PWM.SetFreq(38000, 50)
IR_UART.SetRX(PORTC.2)
IR_UART.SetMode(umTrue)
IR_UART.SetBaudrate(sbr300)
DelayMS(150)
LCD.Cls
LCD.WriteAt(1,1,"IR UART")
While True
IR_UART.Read(Variable)
LCD.WriteAt(2,1,Convert.DecToStr(Variable,3))
Wend
In your IR diagrams above you use a 28 Pin PIC (PIC18F2550). Is there any issue with using a "smaller" PIC such as the (PIC12F508) or even the (rfPIC12C509AF)?
As well, with my project I want to have the PIC control up to 5 LED/bulb lights and have them randomly fade brighter to dim, is that too much to ask of one MCU to be doing the IR and the LED control?
Because my rocks need to have a 360 degree line of sight, I was considering putting 3 inside each so they point outwards in a triangle configuration, can you just add IR LED's (TX and TR) as you would normal LED's (in series) or is there power issues?
For all the grounds in the schematics, where do those attach? Would they just be attached to the resin core?
its a higher language compiler that gives the user a real modular structured approach to PIC programming. It's designed for the 18F range of PIC's, so the smallest you could go is the 18 Pin 18F1320.
The LED's that I use had a 1.6V forward voltage drop. As I am driving with a ULN2003, it too has a 0.9V drop. Working with that, you could calculate the resistor requirements for different configurations, but instead of putting two LED's in series and one in parallel, it would probably be easier to simply drive all three LED's in parallel (each one with a separate 25 ohm or greater LED)
Cool, the only reason I ask is because I'm very limited for space in those things and I need a small chip, that can do what I need. As well there doesn't seem much point in putting 20 DIP PIC's in there when I'm only using two or three of the DIP's. I'm not sure what the price difference is, but I'm assuming I would be paying for stuff I wouldn't be using.
Ok sweet. One of my concerns is driving the TX, the RX, the LED's the MCU, and such. I heard that IR takes a lot of power, so I need to find a decent battery to power all these things.
In your website, you're programming the IR's to put out pulses at certain frequencies am I right? In your opinion do you think for what I'm trying to do would it be better to just have the transmitting IR's send 3 different frequencies, or have them all one one frequency and send unique ID's?
Circuit 1 transmits 100
Circuit 2 transmits 200
Circuit 3 transmits 250
So do I need to have two receiver LED's per stone, or can one receiver LED jump between the two efficiently enough without getting confused?
This is perfect if you only want the devices to turn on if all three are close
Nice project, are the rocks RGB?
Looking back at your diagrams you posted, you seem to have two separate MCU's. I'm assuming (as I have seen it before) you can just put the TX or the TR from another DIP and use one chip (as well as the normal LEDs)?
We use cookies and similar technologies for the following purposes:
Do you accept cookies and these technologies?
We use cookies and similar technologies for the following purposes:
Do you accept cookies and these technologies?