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Bitcoin => Bitcoin Discussion => Topic started by: fennec on June 14, 2011, 06:55:43 AM



Title: Dead simple Bitcoin converter with live rates
Post by: fennec on June 14, 2011, 06:55:43 AM
Hey guys,

I built this over the weekend. You can use it to convert any amount to or from BTC, or just to see the current exchange rate.

Try putting in the number of Bitcoins you have and seeing the dollar value change (hopefully rise :)) over time. You can also convert to Bitcoin by entering a USD amount (more currencies coming).

Check it out at preev.com (http://preev.com).

Let me know what you think! Comments, questions, and criticism welcome.

P.S. Internet Explorer support is pretty minimal (for now).


Title: Re: Dead simple Bitcoin converter with live rates
Post by: Stephen Gornick on June 14, 2011, 09:08:21 AM
Check it out at preev.com (http://preev.com).

Let me know what you think! Comments, questions, and criticism welcome.

Nice!

What is in demand is a widget that works on a third party site but allows me to enter values like what you have.


Title: Re: Dead simple Bitcoin converter with live rates
Post by: fennec on June 14, 2011, 09:22:49 AM
Thanks,

I hadn't considered a widget, but it's definitely an interesting idea. Do you know who wants it specifically?
I'll have a think about how I might build it and get back to you.


Title: Re: Dead simple Bitcoin converter with live rates
Post by: Marcus on June 14, 2011, 09:23:27 AM
.
Fennec -

Making something simple is rarely easy.
Your converter is nicely done.

I want to encourage you to continue thinking and building as you have.
So I've just now sent one Bitcoin to the address on your web page.


Title: Re: Dead simple Bitcoin converter with live rates
Post by: fennec on June 14, 2011, 09:33:17 AM
Marcus,

Thanks so much for your kind words and donation!

I want to help make Bitcoin more accessible to everyone (not just us techy folks), so I plan to continue building tools that are simple and easy to use.


Title: Re: Dead simple Bitcoin converter with live rates
Post by: Electrongolf on June 14, 2011, 10:08:51 AM
This is very cool! I'm sure merchants could use this. One of the problems with BTC is the fluctuating price. I'd like to see USD automatically converted to BTC on merchant sites.


Title: Re: Dead simple Bitcoin converter with live rates
Post by: fennec on June 14, 2011, 10:23:47 AM
Thanks Electron!

I think you're right about price fluctuations; after I build a widget I'll contact some merchants.


Title: Re: Dead simple Bitcoin converter with live rates
Post by: stakhanov on June 14, 2011, 10:26:02 AM
Nice project! How do you compute the current rate? If you want something a bit more robust than simply taking the last trades, I would suggest looking at what I did for the KDE widget: http://kde-apps.org/content/show.php?content=138572 (uncompress the archive, the code is inside and should be straightforward to understand).


Title: Re: Dead simple Bitcoin converter with live rates
Post by: fennec on June 14, 2011, 10:44:52 AM
Cheers stakhanov!

Currently, it's simply using the last price on Mt Gox. I'm planning to alter the calculation to include other (higher volume) exchanges.

I'm not at home right now, but I'll have a look at the code later. Thanks.


Title: Re: Dead simple Bitcoin converter with live rates
Post by: fennec on July 07, 2011, 07:29:56 AM
Hey everyone,

Just a quick update, since I finally found some more time to work on this.

I've added 7 major currencies (AUD, CAD, CHF, EUR, GBP, RUB, SEK) for a total of 8 including USD. Also a few other small improvements e.g added the calculation result in the tab title, so you can see the live amount while browsing other tabs.

Again, all comments etc welcome.

Cheers


Title: Re: Dead simple Bitcoin converter with live rates
Post by: brandondayton on October 13, 2011, 07:11:57 PM
This is exactly the type of tool merchants need. BTW, I've been trying to get the script to work and haven't had any luck. Maybe I don't know enough about Java.


Title: Re: Dead simple Bitcoin converter with live rates
Post by: speeder on October 13, 2011, 07:14:10 PM
I wish it had BRL...

But nice anyway! Very elegant design!


Title: Re: Dead simple Bitcoin converter with live rates
Post by: DeathAndTaxes on October 13, 2011, 08:08:42 PM
Cheers stakhanov!

Currently, it's simply using the last price on Mt Gox. I'm planning to alter the calculation to include other (higher volume) exchanges.

The number of exchanges isn't that important.  Mt Gox has 90% of the volume.

A better algorithm would be one which is volume weighted over a period of time. 

Say in last hour there were 5 transactions.

1000 BTC @ $3.99
 200 BTC @ $4.06
 800 BTC @ $4.01
    1 BTC @ $4.80

obviously the $4.80 is an abberation but it is what users would see. 

Taking a weighted average (volume * price) / (total volume) = $4.01 (technically $4.005397).

The only thing to consider is how large of a weighting period.  The shorter the period the more reactive the average.  The longer the period the more it smooths out the spikes but the longer it takes to react to sustained price action.

For a more "immediate value" I think 1 hour would be good starting timeframe but you may need to adjust.


Title: Re: Dead simple Bitcoin converter with live rates
Post by: fennec on October 15, 2011, 02:14:23 PM
This is exactly the type of tool merchants need. BTW, I've been trying to get the script to work and haven't had any luck. Maybe I don't know enough about Java.

I never got around to creating a merchant tool, unfortunately. Which script are you referring to?

I wish it had BRL...

But nice anyway! Very elegant design!

Thanks! Shouldn't be too hard. I might have some time in the next week, so I'll see what I can do.


The number of exchanges isn't that important.  Mt Gox has 90% of the volume.

A better algorithm would be one which is volume weighted over a period of time. 

Say in last hour there were 5 transactions.

1000 BTC @ $3.99
 200 BTC @ $4.06
 800 BTC @ $4.01
    1 BTC @ $4.80

obviously the $4.80 is an abberation but it is what users would see. 

Taking a weighted average (volume * price) / (total volume) = $4.01 (technically $4.005397).

The only thing to consider is how large of a weighting period.  The shorter the period the more reactive the average.  The longer the period the more it smooths out the spikes but the longer it takes to react to sustained price action.

For a more "immediate value" I think 1 hour would be good starting timeframe but you may need to adjust.

You're right, the last price can be deceptive. I agree with your volume weighted average idea, I'll implement when I get a chance.

Cheers guys!


Title: Re: Dead simple Bitcoin converter with live rates
Post by: brandondayton on October 17, 2011, 09:01:11 PM
Sorry, I confused your converter with this:

http://sanescreen.org/converter/ (http://sanescreen.org/converter/)


Title: Re: Dead simple Bitcoin converter with live rates
Post by: Newar on June 15, 2012, 02:34:59 AM
This is great!

Are you still working on this? (pleasepleaseplease)

Could you include the data from http://bitcoincharts.com/markets/currencies/ ? It's available as JSON: http://bitcoincharts.com/t/weighted_prices.json


Title: Re: Dead simple Bitcoin converter with live rates
Post by: Bitcoin Oz on June 15, 2012, 08:51:18 AM
If you build a html widget I will stick it on http://bitcoin.me


Title: Re: Dead simple Bitcoin converter with live rates
Post by: JessyMatt on February 23, 2014, 06:49:57 AM
You need to create a wordpress widget for this. I need it for http://www.bitcoinvalues.net/bitcoin-calculator-calculate-current-market-value.html


Title: Re: Dead simple Bitcoin converter with live rates
Post by: V4Vendettas on February 23, 2014, 07:34:40 AM
Would love this as a widget.


Title: Re: Dead simple Bitcoin converter with live rates
Post by: TheButterZone on June 06, 2015, 09:01:09 AM
Having Localbitcoins in the mix is skewing the average high (349.9 makes average go to 243.2 with the rest ~224-227). I would have an average of the arbitraged exchanges (Bitstamp, Bitfinex, BTC-E, etc...) separate from the average of the in-person ones (Localbitcoins, Mycelium Local Trader if you can pull their data).

It seems like every time I turn around, someone in Marketplace is saying they use preev, but the price skewing high means they get less BTC.


Title: Re: Dead simple Bitcoin converter with live rates
Post by: JessyMatt on February 14, 2016, 04:16:16 AM
Have you created the widget for this yet? We're all waiting and willing to donate.


Title: Re: Dead simple Bitcoin converter with live rates
Post by: heliotential on November 15, 2019, 02:21:19 PM
This tool has really caught on and I know plenty of people who use it. However, the conversion rates are off, and that causes a lot undue stress. Could I suggest using https://www.x-rates.com/ to get proper conversion rates or really anything else that updates regularly and puts out similar rates to what google would tell you :)


Title: Re: Dead simple Bitcoin converter with live rates
Post by: cphxxx on November 17, 2020, 11:33:23 PM
its down? no idea how I found this, but I've been looking at this everyday for past few years. please bring it back! :)


Title: Re: Dead simple Bitcoin converter with live rates
Post by: californiaquail on November 11, 2022, 06:33:10 AM
Hey man, I've been using Preev on a daily basis for about 10 years, Daily
What happened to it ?  Seems to have gone away sometimes around 2020(*) 

Anyway, I'd happy to host it again & I sent you a PM. let me know.


Hey guys,
I built this over the weekend. You can use it to convert any amount to or from BTC, or just to see the current exchange rate.
Check it out at preev.com (http://preev.com).
Let me know what you think! Comments, questions, and criticism welcome.
P.S. Internet Explorer support is pretty minimal (for now).


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