Gaussmeter Kit Group-Buy

[David Schwab]

Originally Posted by RedHouse

THE PIC HAS ARRIVED!

Woo Hoo!

[RedHouse]

VERIFIED....IT WORKS.

I popped the PIC into the socket, stacked the two boards and powered it up.

At very first there was nothing showing on the disply, then I remembered what Elepro had said about tweaking the trimpot if there is no display, so I did and sure enough the display fadded into view.

I grabbed a pickup from a box on my bench which happened to be a SD Alnico-II Pro (APS1) and the meter measured the poles (in Ph mode) as follows:

E=781g
A=769g
D=789g
G=797g
B=765g
E=757g

Here is a picture of the test unit just after switching on, after the meter boots-up it zero's itself then looks like this:



Here is the test unit measuring a Seymour Duncal APS1:



Nice work Elepro, my first impression is very nice, it works right from the start, and as advertised.

[mickmutante]

Originally Posted by RedHouse

THE PIC HAS ARRIVED!

I'm going to bolt on down to my shop right now and pop it into the PCB....stay tuned...

Yeah..!!!!!

[-Elepro-]

Ok i'm happy.....

in the last picture it doesn't show well.... but did you have seen in datasheet what's the sensor surface active area? it's important.... you have to put magnet on the right surface of the sensor.... watch my drawing

bye

[Bruce Johnson]

Looks good!

Now that I see the assembled unit, I'll just fit mine into a simple aluminum box and mount the sensor to one end. I'd be using it just like you are there, holding pickups and loose magnets up against it to check for oddballs.

I also have access to a commercial gaussmeter, at the electronics lab down the street that I do occasional work for.

I agree that it would be best for you to do at least one comparison check against a commercial unit, just to see if the numbers are in the right range, before Elepro finishes and ships the batch of chips. Just in case the programming needs to be tweaked a bit.

Once we all get our kits and get them together and running, any of us who can check ours against a commercial unit should post the results back here. That way, we can post some data for all about how this unit reads against known commercial gaussmeters.

Again, no hurry from me, let's do this project right.

If we get to the point of needing a few more orders to make Elepro's price breaks, I'd be willing to spring for an extra one or two kits (which I would assemble and sell).

Or maybe a few of us would like to go in together and "invest" in buying up a larger batch of Elepro's chips as one order. We could then hold them for a while and do a second group buy of the other parts later?

[Dave Kerr]

Might it make sense to group buy a couple extra PICs in case one croaks/is defective? Seems coordinating swapping a part overseas to Italy would be bothersome. Or are these chips pretty bullet-proof once the code's loaded in?

[RedHouse]

Originally Posted by -Elepro-

Ok i'm happy.....

in the last picture it doesn't show well.... but did you have seen in datasheet what's the sensor surface active area? it's important.... you have to put magnet on the right surface of the sensor.... watch my drawing

bye

Yes I got that specification Elepro, in this close-up picture you can see better both the orientation of the sensor (beveled side facing the magnet), and also the little micro-pin-socket lead I made up for this test jig:



The idea behind this socketed sensor lead is, once I get a calibrated known-value magnet to use in the future as a "control" specimen, then I can place each A1302 sensor into this socketed test harness and measure with the known-value magnet I should be able to find the right offset for each sensor if needed .
(this sensor lead is not the lead I'll be using in my final meter, it's just for testing purposes)

[-Elepro-]

Originally Posted by Dave Kerr

Might it make sense to group buy a couple extra PICs in case one croaks/is defective? Seems coordinating swapping a part overseas to Italy would be bothersome. Or are these chips pretty bullet-proof once the code's loaded in?

i test all chip that i send.... i built another gaussmeter just for this.....
certanly if someone put chip in wrong side or if the board has some other problem (bad solder, short circuit, a defective 7805 ecc ecc....) or if someone plug gaussmeter directly into the wall ... then pic can has some problems

in photo my gaussmeter, a gaussmeter built just for PICs test and some PICs.....

[-Elepro-]

Originally Posted by RedHouse

Yes I got that specification Elepro, in this close-up picture you can see better both the orientation of the sensor (beveled side facing the magnet), and also the little micro-pin-socket lead I made up for this test jig:

perfect .... excuse me for unnecessary information.....

Originally Posted by RedHouse

The idea behind this socketed sensor lead is, once I get a calibrated known-value magnet to use in the future as a "control" specimen, then I can place each A1302 sensor into this socketed test harness and measure with the known-value magnet I should be able to find the right offset for each sensor if needed .
(this sensor lead is not the lead I'll be using in my final meter, it's just for testing purposes)

great idea....

[RedHouse]

Originally Posted by Bruce Johnson

...If we get to the point of needing a few more orders to make Elepro's price breaks, I'd be willing to spring for an extra one or two kits (which I would assemble and sell)....

Now's the time to speak-up for shure, we're getting close to the Last Call.

Originally Posted by Dave Kerr

Might it make sense to group buy a couple extra PICs in case one croaks/is defective? Seems coordinating swapping a part overseas to Italy would be bothersome. Or are these chips pretty bullet-proof once the code's loaded in?

I'm not shure any swapping will be in the future, there was no implied guarantee with these if that's what you mean. If you mean simply aquiring a new PIC if your's goes T.U. then yeah, now's the time to speak-up for shure.

It's too early to go into details, but I'm communicating with Elepro off-line regarding future kit offerings, but know that it wouldn't be realized at this kind of bare-bones price point. This bare-bones price is because each participant has to invest sweat-equity, assembly, wiring, and work out the housing specifics. A "Ramsey" style kit where you solder-n-go will cost more, and obviously a fully assembled unit would too, but either case would still be well under the cost of a current production hand-held gauss meter.

[RedHouse]

Originally Posted by -Elepro-

i test all chip that i send.... i built another gaussmeter just for this.....
certanly if someone put chip in wrong side or if the board has some other problem (bad solder, short circuit, a defective 7805 ecc ecc....) or if someone plug gaussmeter directly into the wall ... then pic can has some problems

in photo my gaussmeter, a gaussmeter built just for PICs test and some PICs.....

Elepro, check your PM's

Also, with regards to the various skill levels of participants in this group-buy, and since inserting the PIC wrong can blow it out, I think you and I should agree on how to insure they are in working order when shipped.

Will you be testing each one prior to shipping to me? should I also be making up another test fixture and test each PIC before I ship it out?.

[Dave Kerr]

I'm a bit of a rube when it comes to this stuff, was just wondering aloud whether it made sense to have a spare kicking around stateside somewhere. If there's a high likelihood that if this thing doesn't work it'll be due to my error and not a defective PIC I'm cool with that.

[David King]

People assembling this kit should probably read up on working with C-mos components and how to avoid static discharge when they are handling them. It should not be much of an issue in summertime with the humidity but if you wear plastic shoes and have wall to wall carpeting then I can see where there could be tears.

[Arndawg56]

Originally Posted by RedHouse

VERIFIED....IT WORKS.

I popped the PIC into the socket, stacked the two boards and powered it up.

At very first there was nothing showing on the disply, then I remembered what Elepro had said about tweaking the trimpot if there is no display, so I did and sure enough the display fadded into view.

I grabbed a pickup from a box on my bench which happened to be a SD Alnico-II Pro (APS1) and the meter measured the poles (in Ph mode) as follows:

E=781g
A=769g
D=789g
G=797g
B=765g
E=757g

Here is a picture of the test unit just after switching on, after the meter boots-up it zero's itself then looks like this:



Here is the test unit measuring a Seymour Duncal APS1:



Nice work Elepro, my first impression is very nice, it works right from the start, and as advertised.

I say if they work, go ahead with the "last call" and order everything up. Can you maybe make arrangements to compare it to a commercial unit while the parts are being shipped. I would prefer to get mine as soon as possible. We all agreed to the purchase these before Red House offered comparing it to the commercial unit. Besides, you never know how long it might take to get a meeting set up to agree with Red House's and the guy with the commercial meters schedule!

[RedHouse]

Originally Posted by Arndawg56

I say if they work, go ahead with the "last call" and order everything up....Can you maybe make arrangements to compare it to a commercial unit while the parts are being shipped....Besides, you never know how long it might take to get a meeting set up to agree with Red House's and the guy with the commercial meters schedule!

I'm trying to make arrangements as we speak (or as we post).

As you all know, this time of year is quite hard to sched stuff because of vacations and summer things, office party's, B'days, weekends with family etc.

I have a couple hours this Sunday, and either day next weekend left open to do it, after that I'm booked-up until the second week of September ....unless something breaks loose off my schedule.

Funny, seems we drifted away from holding off last call until I could recieve, build and validate the unit, and now we're waiting on further assesment?.

[defaced]

Originally Posted by RedHouse

Funny, seems we drifted away from holding off last call until I could recieve, build and validate the unit, and now we're waiting on further assesment?.

Originally Posted by RedHouse

When the PIC arrives and I get the verification-build assembled and running, how many in the group-buy would like us to call that good and proceed with Last Call ...or... would the group prefer to wait until I can get the verification-build over to Wolfe or Jason to test it up against a commercial unit.

Um, unless I missed something, it looks like it was your idea, and I think a good one.

[RedHouse]

Originally Posted by defaced

Um, unless I missed something, it looks like it was your idea, and I think a good one.

So it was, thank you Mike.

UPDATE:
We'll be going into an in-definate hold on the group-buy.

I'm currently working at scheduling a date/time to validate against a commercial unit. I have a narrow window of opportunity in the very near future, for me this Sunday is open but I have not heared from Wolfe or Jason regarding this weekend and as today is Friday I'm assuming this weekend isn't going to work out. Next Saturday and Sunday are open with me, but if that fails it's looking like the second week of September will be the next available time to sched on my part.

[RedHouse]

Originally Posted by Dave Kerr

I'm a bit of a rube when it comes to this stuff, was just wondering aloud whether it made sense to have a spare kicking around stateside somewhere. If there's a high likelihood that if this thing doesn't work it'll be due to my error and not a defective PIC I'm cool with that.

Would be good, maybe you should be down for 2.

[David King]

I don't care about a calibrated unit as all of my measurements will be relative anyway. Even 10% off is plenty good since the Gauss units are kinda meaningless in the grand scheme of things.

[automan]

Redhouse, can I go ahead and send you cash for mine? I am about to relocate my family, school, and life across the country from Boston to Nashville. I would rather go ahead and get the money out rather than have to explain to my wife why I am spending money on this after the move when things wont be quite as easy as they are now (at least for a time.)

[RedHouse]

Originally Posted by automan

Redhouse, can I go ahead and send you cash for mine? I am about to relocate my family, school, and life across the country from Boston to Nashville. I would rather go ahead and get the money out rather than have to explain to my wife why I am spending money on this after the move when things wont be quite as easy as they are now (at least for a time.)

You have a PM

[RedHouse]

UPDATE:
New development....

I have been in contact with WolfeM and S.Lollar today, we may be able to get this assesment thing cleared up by Sunday afternoon ....stay tuned!

....tic...tic...tic...tic...

[David Schwab]

Originally Posted by RedHouse

I have been in contact with WolfeM and S.Lollar today

S.Lollar? Is that Jason's sister Suzy Q. Lollar?

[Dave Kerr]

My guess would be Stephanie

[RedHouse]

Originally Posted by Dave Kerr

My guess would be Stephanie

Bing!

[RedHouse]

VERIFIED....(again)....IT SO WORKS!.

My wife and I just got back from Vashon Island, I was able to meet with Jason & Stephanie Lollar today (Sunday) and I met with Wolfe Marshall yesterday (Saturday).

(BTW; thank you all for helping us out with this! it was my pleasure meeting with you)

Our DIY meter was testing high, anywhere between 50 to 150 gauss at various readings.

When I say "anywhere" well it seems that taking readings is not a straight forward operation as I thought it would be. Apparently sensors (both ours and the ones in the commercial gaussmeters) have a sweet spot and less-than-sweet-spot and magnets have a different reading in different places on them, and our fingers/hands can throw off a reading.

I wrote down the readings, and asked Jason and Wolfe to test a couple magnets I had brought along so I could use them as "control specimens" later.

Both took several readings, which is apparently more than necessary, and later when I got home (which was just now) I sat down with our meter and started messing around with the re-calibation adjustment mode to see if I could get our meter to match the results of the professional meters (3 commercial meters in all were used, Wolfe mentioned his was in the neighborhood of $1200) on these "control specimen" magnets.

Magnets are much more "alive" than I ever imagined.

After adjusting our meter from 1.30mV/G -to- 1.36mV/G setting I was able to get identical readings that Jason and Wolf got on their professional meters when they measured my "control specimen " magnets.

Just now I re-tested that APS-1 (Duncan Alnico-II Pro) Strat pickup I posted earlier and got these results after re-calibrating:

E=769G ...(was 781g)
A=709G ...(was 769g)
D=758G ...(was 789g)
G=772G ...(was 797g)
B=742H ...(was 765g)
E=733G ...(was 757g)

I'm convinced we have a decent and fairly accurate gauss meter. When I say "fairly" it's because of what I've recently learned about measuring magnets and because I saw that even the professional meters readings vary on the same magnet from one reading to the next.

I'm convinced now that a 50-75G (even up to up to a 100G) "window" would be an ok tolerance to call "accurate" because you can easily get that much variation just by moving the sensor/magnet around while taking a reading.

BTW, the peak-hold feature is the shit! makes the whole process of taking readings way easier, both Wolfe and Jason commented about it.

I'm going to call this good and go have dinner and a glass of wine. I will make another post later this evening announcing our Last Call on this group-buy.

YEAH BABY!

[David Schwab]

Cool beans!

And thanks to the Lollars and Mr. Marshall.

I'd assume calibration would vary from sensor to sensor? Do the sensors come in a batch?

As with a lot of people here, a relative measurement is fine with me.

[defaced]

Excellent news. Thank you for going the extra mile, and thank you to the Lollars and Mr. Marshall for donating their time to help with our group buy.

I'm ready to ink this deal. Last call?

[mickmutante]

Originally Posted by RedHouse

I'm going to call this good and go have dinner and a glass of wine.

Yuuummmyyyy..!!!

Originally Posted by RedHouse

... I will make another post later this evening announcing our Last Call on this group-buy.

YEAH BABY!

Rock 'N Roll.....!!!!!!

[RedHouse]

Originally Posted by David Schwab

...I'd assume calibration would vary from sensor to sensor? Do the sensors come in a batch?....

Dunno really, but I have another plan regarding that.

Look at this picture:



you can see I made a special probe lead wire on this test unit which has micro-sockets at it's end. My plan was to use it to test each persons A1302 and find the right calibration numbers. I'd write them on a piece of paper in each participants package so if you wish you can set your calibration to the closest we can come to an absolute reading. I have the 3 magnets that were measured by Jason and Wolfe here on my bench we can use them as "control" specimens.

Now I'm sure someone will chime-in about the 7805 and how each has a slightly different actual output voltage (like 5.2 volts or 5.13 or whatever) and how the A1302 data sheet says that power supply voltage can offset the unit ...but we're talking minutae here.

[Arndawg56]

Originally Posted by RedHouse

VERIFIED....(again)....IT SO WORKS!.

My wife and I just got back from Vashon Island, I was able to meet with Jason & Stephanie Lollar today (Sunday) and I met with Wolfe Marshall yesterday (Saturday).

(BTW; thank you all for helping us out with this! it was my pleasure meeting with you)

Our DIY meter was testing high, anywhere between 50 to 150 gauss at various readings.

When I say "anywhere" well it seems that taking readings is not a straight forward operation as I thought it would be. Apparently sensors (both ours and the ones in the commercial gaussmeters) have a sweet spot and less-than-sweet-spot and magnets have a different reading in different places on them, and our fingers/hands can throw off a reading.

I wrote down the readings, and asked Jason and Wolfe to test a couple magnets I had brought along so I could use them as "control specimens" later.

Both took several readings, which is apparently more than necessary, and later when I got home (which was just now) I sat down with our meter and started messing around with the re-calibation adjustment mode to see if I could get our meter to match the results of the professional meters (3 commercial meters in all were used, Wolfe mentioned his was in the neighborhood of $1200) on these "control specimen" magnets.

Magnets are much more "alive" than I ever imagined.

After adjusting our meter from 1.30mV/G -to- 1.36mV/G setting I was able to get identical readings that Jason and Wolf got on their professional meters when they measured my "control specimen " magnets.

Just now I re-tested that APS-1 (Duncan Alnico-II Pro) Strat pickup I posted earlier and got these results after re-calibrating:

E=769G ...(was 781g)
A=709G ...(was 769g)
D=758G ...(was 789g)
G=772G ...(was 797g)
B=742H ...(was 765g)
E=733G ...(was 757g)

I'm convinced we have a decent and fairly accurate gauss meter. When I say "fairly" it's because of what I've recently learned about measuring magnets and because I saw that even the professional meters readings vary on the same magnet from one reading to the next.

I'm convinced now that a 50-75G (even up to up to a 100G) "window" would be an ok tolerance to call "accurate" because you can easily get that much variation just by moving the sensor/magnet around while taking a reading.

BTW, the peak-hold feature is the shit! makes the whole process of taking readings way easier, both Wolfe and Jason commented about it.

I'm going to call this good and go have dinner and a glass of wine. I will make another post later this evening announcing our Last Call on this group-buy.

YEAH BABY!

Thanks to everyone involved. I am sooo ready. Lets ink this deal

[RedHouse]

LAST CALL....

Last call will start now as we close this group-buy this week.

Those who are "in" will need to start sending their fundage. Paypal or US Postal Money Orders only.

Participants who want to pay by US Postal Money order need to get them in the mail Monday or Tuesday (July 7 or 8th) and send them in a manner that gets them to me in time. You will need to PM me for the address to send your M/O

Participants who will be paying by Paypal have until 4PM next Saturday August 1st to get their payment to me. My Paypal address is brad.anne.burt AT gmail.com

I will be ordering the Parts and PIC's Monday August 3rd. I must emphasize that you MUST make sure your fundage gets to me before 4PM next Saturday Aug 1, 2009 or you are not going to make it in on this group buy.

Anyone who has been on-the-fence will needs to decide if they are in and get their fundage transfered. Please don't PM me on Saturday evening asking "is it too late", it will be. Fundage needs to be recieved by Saturday to make the order Monday.(I'm busy Sunday because I swapped this Sunday for next Sunday so I could meet with Jason on behalf of the group)

As some have made comments about multiple kits, you can order more than one PIC but know that you will have to pay more shipping and wait for the extra PICs. We can't have the whole group-buy held up by a few wanting multiples. Also, I offered to make circuit boards for the participants here at $9/per, I did not offer to enable anyone to do business and no multiples are being offered. One PCB per particpant at that price.

REMEMBER:

• If you want to pay by Postal Money Order, PM me for my address and mail it out so it gets here by Saturday August 1st.
• If you want to pay through Paypal, my Paypal address is [I]brad.anne.burt AT gmail.com
• If you want to pay by Credit Card through Paypal you need to add a small amount to your share of the bill, they ding me for accepting credit cards and you will need to cover that cost.

Who's In:


18 Participants:
Redhouse.....(A)
David Schwab
JasonG
spy.....(A)
firewire.....(A)
Bruce Johnson.....(A)
Arndawg56.....(A)
LtKojak.....(A)
mkat
automan.....(A)
Dave Kerr.....(A)
John H
defaced.....(A)
David King.....(A)
StarryNight
mickmutante.....(A)
paulgarstki.....(A)
Jeff Callahan

The names above with the (A) following have PM'd me their mailing address, those who haven't need to get on it.


The finalized parts list and costs:
(note: we are getting quantity discounts on the PIC and the LCD)

R1.....10k trim.....531-PT6KV-10K.....$0.41/ea
R2.....5.6K 1/4w 1%-MF.....271-5.6K-RC.....$0.13/ea
R3.....47ohm 1/4w 1%-MF.....271-47-RC.....$0.13/ea
C1.....330nF polyester.....505-MKS20.33/63/5.....$0.49/ea
C2.....100nF polyester.....505-MKS2.1/63/5T.....$0.27/ea
C3.....100nF polyester.....505-MKS2.1/63/5T.....$0.27/ea
C4.....100nF polyester.....505-MKS02.1/63/10.....$0.45/ea
D1....1N4001.....625-1N4001-E3/54.....$0.04/ea
IC1.....7805T.....863-MC7805BTG.....$0.55/ea
(2) N.O. MOM switch.....506-MSPS103C0.....$1.51/ea
(2) SPST mini toggle.....611-7101-064.....$4.29/ea
(2) DIP14 (for IC3).....517-4814-3000-CP.....$0.19/ea
9v batt clip.....534-84-6.....$0.44/ea
Header.....517-929834-01-16.....$0.58/ea
Socket.....517-974-01-16.....$1.76/ea
IC2.....A1302 (hall sensor).....$1.50/ea
LCD Display.....763-0216K1Z-FSW-FBW.....$9.60/ea
(at the 10+ price break from Mouser)
IC3.....PIC16F883 pre-programmed by Elepro.....20-euro/$27.87
(M#579-PIC16F883-I/SP)
(at the 15+ price break from Elepro)
PCB.....$9
Mouser shipping ($10 divided by 15 participants).....$0.67
USPS Priority shipping to USA participants.....$4.95

Total (w/o terminals) ----------------- $71.00
Total if paying with Credit Card ---------- $73.00

Note: LtKojack and Spy have a separate international shipping charge which I have PM/email them about, they need to select the type.


Status:
we are closing this group-buy

[LtKojak]

Originally Posted by RedHouse

VERIFIED....(again)....IT SO WORKS!.

My wife and I just got back from Vashon Island, I was able to meet with Jason & Stephanie Lollar today (Sunday) and I met with Wolfe Marshall yesterday (Saturday).

(BTW; thank you all for helping us out with this! it was my pleasure meeting with you)

Our DIY meter was testing high, anywhere between 50 to 150 gauss at various readings.

When I say "anywhere" well it seems that taking readings is not a straight forward operation as I thought it would be. Apparently sensors (both ours and the ones in the commercial gaussmeters) have a sweet spot and less-than-sweet-spot and magnets have a different reading in different places on them, and our fingers/hands can throw off a reading.

I wrote down the readings, and asked Jason and Wolfe to test a couple magnets I had brought along so I could use them as "control specimens" later.

Both took several readings, which is apparently more than necessary, and later when I got home (which was just now) I sat down with our meter and started messing around with the re-calibation adjustment mode to see if I could get our meter to match the results of the professional meters (3 commercial meters in all were used, Wolfe mentioned his was in the neighborhood of $1200) on these "control specimen" magnets.

Magnets are much more "alive" than I ever imagined.

After adjusting our meter from 1.30mV/G -to- 1.36mV/G setting I was able to get identical readings that Jason and Wolf got on their professional meters when they measured my "control specimen " magnets.

Just now I re-tested that APS-1 (Duncan Alnico-II Pro) Strat pickup I posted earlier and got these results after re-calibrating:

E=769G ...(was 781g)
A=709G ...(was 769g)
D=758G ...(was 789g)
G=772G ...(was 797g)
B=742H ...(was 765g)
E=733G ...(was 757g)

I'm convinced we have a decent and fairly accurate gauss meter. When I say "fairly" it's because of what I've recently learned about measuring magnets and because I saw that even the professional meters readings vary on the same magnet from one reading to the next.

I'm convinced now that a 50-75G (even up to up to a 100G) "window" would be an ok tolerance to call "accurate" because you can easily get that much variation just by moving the sensor/magnet around while taking a reading.

BTW, the peak-hold feature is the shit! makes the whole process of taking readings way easier, both Wolfe and Jason commented about it.

I'm going to call this good and go have dinner and a glass of wine. I will make another post later this evening announcing our Last Call on this group-buy.

YEAH BABY!

Wow! Just... wow!

This is excellent!

I just can't wait to get my hands on it.

Thank you Brad for going the extra mile in behalf of everybody and thanks to Wolfe and Jason&Stephanie for their generosity grantin' access to their measure instruments.

Now I feel just like doin' the banana dance!

Please, don't watch, it's not a pretty sight...

[RedHouse]

Head's-up ....New Development:

Elepro just found out that Paypal will try to ding him 3,4% + 0,35€ for doing a US Dollars -to- Euro's money transfer. Having already given us additional discounts on our PIC's, he and I both agreee it wouldn't be right that he should have to eat the fee's.

Which means we'll have to either cough-up some additional fundage for the Paypal conversion fee, or possibly use another form of money transfer. Elepro mentioned MoneyGram (which I know nothing about) so I asked him to help me look into it as an option.

(those Paypal buggers don't miss a trick do they!)

Everything is still a GO we just have this one last kink to work out.

[David King]

Paypal is still pretty much the best game in town as the banks will all charge at least $35 for a wire transfer at this end and may ding Elepro another $10-$15 at his end and that's NOT counting the bank currency exchange rate which can be anywhere from 1.5% to 4% off the official rate.

I say just add 4% to everyone's cost for the PIC and be done with it.
4% of $20 is only .80 cents if I'm not mistaken.

If you want to see the daily exchange rate, I use this tool:
http://www.oanda.com/convert/classic