Free Range Robots (IR Beacon) **UPDATED**

Let's Make Robots
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1

**Update 4.14.09***

OK, when you watch the video...

First of all, it is like, 5 minutes -sorry. There is a point though promise, and that point starts at about 3:40 or so. Now, I can't stress enough, the code is wicked chunky as it was written in about 10 min. It is all "bang-bang" and not proportional at all. The final code should be about 10x faster, much more accurate with a lot less trial and error. For now, this is just proof of concept and indeed it has been proven.

 

https://www.youtube.com/watch?v=-zl-PBPUf3c
2

Let’s talk infra red

Chris wrote elsewhere

"…

I started to do some math. $4 for a 08m, $.08 per IR led (needing 3-5 per “beacon”), $1 AA battery holder, some scrap PCB. I’m looking at about 7 bucks per “beacon”. With 2 per room (each set to a different output code number) you are looking at $15 or so. --With 2 in each room you can allow for some pretty good triangulation. Even if you add another couple IR led’s and a IR transistor, you would still only be up to about $20 bucks a room and with the extra LED and sensor, you could set a beam at the doorway to trigger the beacons to come on for 5 min’s or so. The rest of the time, they sleep -batteries would last a long time.

…"

I’m wondering why spend $4 on a micro controller. I admit, I do not know the design of the individual beacon. It’s the multiplication of low costs that would drive me insane.

Awakening the beacon from sleep mode: nice touch. But do you really want Bondo to set them off? Or the kids, or anyone else? With a more sophisticated design (not necessarily more expensive) you could have Walter send a trigger. Maybe a flash of IR.

Talking rooms: If the rooms are gonna talk to Walter, why not let them say directly which room they are? IR could easily encode an 8bit message. Or os this the whole purpose of the 08M?

 

3

cool ! is there a page
cool ! is there a page explaning how to make a beacon , transmitter or reciver?

4

They would say what room they are…

Yeah rik,

Using the IRIN command, you have 128 available codes that can be spit-out and read. Each beacon would have it’s own “frequency” and there would be 2 per room again, each having its own code number. With a beacon in each corner, walter could center himself between the two, be a given distance back from them (from the triangulation), know which one is on the left and right and know what room he is in. Using these beacons in a few stratigic locations, and an eeprom table of distances to and from other places… well. In terms of false triggers turning the beacons on, I really don’t have a problem with that --anything is better than having them blinking away all day and night. -or- get a good deal on some wall-plug transformers and have all the beacons AC powered and simply blinking all the time -but now plugged in.

5

Vince–
This is just the basic picaxe IR set-up, the one with the 3-pin receiver. The only difference is that I stuck the receiver in the end of a tube with the inside painted black. With the receiver shielded this way, it can only see a signal coming directly in front of it. Badda boom badda bing.

6

Does that servo…

turn a full 360 degrees or is it some kind of jiggery pokery with the gears?

 

 

looks like an interesting project dude.

7

180 degree servo
The 360 comes from the gear ratio. The jitter comes from the fact that I am running on only 3 AA’s and the backlight of the LCD is stealing a lot of the servo’s juice.

8

I never thought

Of that, what a great way to do it. Saves you opening the servo case and medling.

Do you alter the code for it at all, like halfing the degrees?

 

e.g

 

180* 2 = 360

9

4 bucks?
Hi rik, what’s $4 for a 08m? - if your trying to do a specific frequency ID for a beacon could’nt you just use a ne556 and a couple caps and a resistor ($0.55). Since you can use both timers - it can be outputing 2 frequencies simultaneously.

10

which is exactly what oddbot suggested

in the previous thread.

The $4 needs multuplying by 2 and the number of rooms, in Chris’ plans. The lower the unit cost, the higher the multiplier can go within the same budget.

11

i like the idea of a beacons

i like the idea of a beacons more -

2 different beacons at the opposite ends of a room on different frequency could ID the room,

but (even better) - if you find the Heading (as CTC has done) on both beacons - do a little Trig. and Viola ! You know the ~exact position of Walter within the room !

it might take 2 readings & encoder output of relative position - but then you could derive absolute position - then Walter can start drawing a map - you could post it - then we all could see CTC’s floor plan of his house

Nifty - I like it

What are you using for components CTC, so I can blatantly copy you :slight_smile:

12

I gotta go do Easter stuff…
I will do a proper post tonight (with pretty pictures) and all the componants I am using. Promise

13

<3
Cheers dude, looking forward to it.

14

ohhhhh thanks ! never got

ohhhhh thanks ! never got that thing working.

Am I the only one that sees a problem with the idea of 2 becons in a room?

15

How I did it…

The IR sensor and IR LED are done exactly per the picaxe manual’s instructions, period. To get the sensor to respond “directionally” I simply put it at the end of a small tube and crimped down the other end leaving just a small hole. The inside is painted black. Like this:

 

Walter_Autodrive_Update_015.jpg

That's it.

I have the IR led's on the transmitter (beacon) sending out a constant command (the equivalant of holding down a button on a remote) and the servo scans and sees if the sensor can see the IR beam at each location. With the set-up I have now, it can find/miss the beacon withing 5 servo steps. I.e. if I have the servo go in 5-step steps, it will jump over the beam a lot... In 2-step steps it will find it every time.

Here's the code I am using:

pause 1000
gosub clearscreen
gosub mainscreen
servo 1,225
pause 500


buttonmain:
if pin1=1 then
gosub clearscreen
setfreq m8
serout 0,T9600_8,(254, 128) 'Sets line 1 position 1
serout 0,T9600_8,("Starting Sweep ")
serout 0,T9600_8,(254, 192) 'Sets line 2 position 1
serout 0,T9600_8,("IR Beacon ")
setfreq m4
servo 1,225
pause 500
gosub roomone
endif
goto buttonmain


mainscreen:
setfreq m8
serout 0,T9600_8,(254, 128) 'Sets line 1 position 1
serout 0,T9600_8,("Button 1 ")
serout 0,T9600_8,(254, 192) 'Sets line 2 position 1
serout 0,T9600_8,("To Start Sweep ")
setfreq m4
return

clearscreen:
setfreq m8
serout 0,T9600_8,(254, $01)
pause 10
serout 0,T9600_8,(254, $01)
pause 10
setfreq m4
return

roomone:
let b2=200
gosub servomove

let b2=180
gosub servomove

let b2=145
gosub servomove

let b2=120
gosub servomove

let b2=90
gosub servomove

let b2=68
gosub servomove

let b2=35
gosub servomove


goto buttonmain

servomove:
servo 1,b2
pause 500
gosub ircheck
return

ircheck:
IRIN [100,ircheck2],4,b1
if b1=11 then foundit
ircheck2:
return

foundit:
gosub clearscreen
setfreq m8
serout 0,T9600_8,(254, 128) 'Sets line 1 position 1
serout 0,T9600_8,("Beacon Heading")
serout 0,T9600_8,(254, 192) 'Sets line 2 position 1
serout 0,T9600_8,(#b2," O'clock")
setfreq m4
pause 5000
gosub clearscreen
gosub mainscreen
goto buttonmain

16

4 way

Maybe you could set your system up so that the receiver has more than one sensor. Only thing I see resembling this pre-built on the market is the Pololu tranceiver pair, but they’re kinda expensive. But they do have a good idea there, those Pololu dudes.

Anyway, cool project! I’ve always wanted to do that!

17

IR parts

That is beyond awesome. This IR triangulation is a breakthrough.

Expect on having lots of imitators. LoraxVision!

Does Walter use the IR reciever that Rev Ed sells? I tried to locate a US distributer for that part and was told they are no longer in production …

I found a bunch of Sharp GP1u5’s at a local shop, but haven’t been able to get it connected to my axe.

 

18

It’s just the regular ol’ part…
3-pin, 38khz IR receiver -as shown in the picaxe manual. --That’s it

19

IR parts : World Educational
IR parts : World Educational Services says that the Rev Ed IR receiver part is a TSOP18xx. Try checking out that datasheet for compatibility to the Sharp GP1U5 parts you have, checking frequency, and also look over Panasonic PNA4602. I’ve used a couple Sharps, but prefer the Panasonic part as it seems more sensitive.

20

I use the one…

I use the one that radio shack sells because I live 40 miles out in the middle of the damn ocean and it’s the only one I can get unless I want to spend 5 bucks shipping on a 1 dolla part!

Ting!