Distance sensor schematic question.

[corrado33]

I know this is stupid... but I just want to make sure.

On THIS schematic.


I provide +5V to pins 11, 12 and 14, correct?  I only ask because only 12 has an arrow pointing in but the others do have a generic +Source signal. Besides, it doesn't look like it'd work if I didn't power those pins. 

[waltr]

A part number and a link to the full data sheet would be helpful. The two pin with Vcc are power but I will not say if the power is 5V without seeing the specs in the data sheet.
Pin 12 could be just the same as Vcc or it is a control input. Again can't say with seeing the data sheet.

[corrado33]

Ask, and you shall receive.
http://sharp-world.com/products/device/lineup/data/pdf/datasheet/gp2y0d810z_e.pdf


I bought them cause they were cheap, hoping I could get some use out of them.  

EDIT:  Now that I read a little deeper into the datasheet.... VCC is .3 to 7V and vin is .3 to vcc+.3 V, so they can both be 5V just fine.  

Oh.... AND Vin is the "on/off" switch.  And this is just a proximity sensor, and won't provide me with actual distance measurements, which is fine.  

Hmmm, question I do have... pin 1 should be connected to pin 3? 

[billhowl]

http://www.pololu.com/catalog/product/1134
http://www.societyofrobots.com/robotforum/index.php?topic=9626.0

operating voltage: 2.7 V to 6.2 V

[Soeren]

Hi,

Ask, and you shall receive.

I thought you were the one asking 

EDIT:  Now that I read a little deeper into the datasheet.... VCC is .3 to 7V and vin is .3 to vcc+.3 V, so they can both be 5V just fine.  

I'm repeating myself (over and over), but anyway... "Absolute Maximum Ratings" is not the chapter to go by in a datasheet. It's just what won't kill of the component right away.
Had you looked a bit deeper - Roughly 6" down - you'd have noticed the "Recommended Operating Conditions", which says...
Supply voltage VCC 2.7 to 6.2 V
High level input voltage VinH (CMOS level signal. Operating) MIN VCC-0.2 V
Low level input voltage VinL (CMOS level signal. Standby state) MAX 0.2 V

Oh.... AND Vin is the "on/off" switch. 

It's the active/standby pin, to be more precise and it needs to be high to work.
All the pins that are brought out means that, you can use it in different ways, but if you just wanna use it "straight up", you connect pins 11 and 14 (remember the 4.3 Ohm resistor ) and while not needed, you can keep it inactive, to lower the current drain to ~5µA, by pulling pin 12 low.

While they're nice for a lot of stuff, especially if they came cheap, they have a fixed distance of 100mm, so will be aces for detecting eg. a hand brought near them (a friend of mine has got a similar device, built into his loo, so you just wave your hand above it to flush). The output is high when it doesn't detect anything and it will pull low when something gets in its field of view withing a 20mm to 100mm distance. Good for anything indoor where you'd have some kind of manual switch normally.

[corrado33]

Wow lots of quick replies.

And I pretty much just made that schematic above.  

And soeren, I DID see the recommended voltages below.  My 5V still falls within them.  

It's funny though, although I've definitely not read through as many datasheets as you guys have, this is probably the first time I've seen "recommended operating conditions".

I can either use these as bump sensors for fun or a magic alarm clock shut-er off-er.  Or a magic light switch... or a magic (do you see where I'm going with this?).. lol

For now, they're going on as bump sensors on my bot so it can drive around and not hit stuff.  

Oh, one more question... it says C1*C2 = 0.1 uF.  Please explain that to me.  Does it literally mean you can choose any values as long as they multiply to 0.1 uF (cause that wouldn't make sense).  

Oh EDIT:  Sorry I didn't search, I figured this was such an obscure thing that no one would have brought it up (let alone type in the entire name of it). 

[Soeren]

Hi,

Remembr that it probably have a rather narrow "beam" of detection, so try it out on a proto board with eg a stick to find the detection angle. You may be able to get a rough idea by looking at it through a cam (just about all I ever use my phone cam for), but the detection angle is probably more narrow than the IR LEDs angle of illumination.

If you're going to mount them so two of them an see each others light, you'll probably get in trouble, although synchronizing (if possible) them will help. If you alternate between them this issue disappears.

[waltr]

Ahh...That device.
I do have a couples of these (on boards from Pololu) on my Bot as touch-less bump sensors. They work well.
The C1*C2 note really seems to mean that both caps should be 0.1uF. These are just by-pass caps for the input Vcc and the internal regulator output.

[corrado33]

Ahh...That device.
I do have a couples of these (on boards from Pololu) on my Bot as touch-less bump sensors. They work well.
The C1*C2 note really seems to mean that both caps should be 0.1uF. These are just by-pass caps for the input Vcc and the internal regulator output.

That's what I thought (and how I initially read it).  Thanks.  

So did they just stick an extra bypass cap onto the schematic above?  As well as an extra LED for fun (probably to tell when it's on).  

Oh btw, the one thing that does suck about these is they have smaller than normal pin spacing (1.5mm), so I can't stick them in a breadboard or proto-board.  I'll just have to make a board for them to go on. 

[waltr]

Yes and no.
The 0.1uF cap is required to be close to the Vcc pin of the chip. The 4.7uF is needed due to the possibility of longish power leads.
The LED is a detection indicator. Remember that the output goes low when an object is detected.

[corrado33]

Yes and no.
The 0.1uF cap is required to be close to the Vcc pin of the chip. The 4.7uF is needed due to the possibility of longish power leads.
The LED is a detection indicator. Remember that the output goes low when an object is detected.

Ahhh...  So a longer power lead could cause lower frequency noise therefor you'd need a bigger cap to filter it out.  Is it just experience or is there a reason 4.7uF was chosen?

I totally forgot the output goes low when it detects something, I like that little LED (although it's not needed in my case).  Maybe for testing.