Ask HN: What are you working on? • Hacker News Board

Re: Ask HN: What are you working on?

#121

Post by joe_bleau » Tue, Jan 05, 2010, 9:03 PM UTC

jacquesm wrote: post #109

jgrahamc wrote: post #102

Earlier quoted context omitted.

Agreed. I am redesigning it for the production version. I'd like to pull everything from the USB if possible.

Have you tried simply raising the ground of the LM 35 by placing a diode in series with the 0 terminal? That way you might just add a single 10ct component and get rid of the problem completely. Just enough to raise the ground of the LM35 above the input sensitivity threshold. One Si diode would probably work, two Ge in series would be slightly better (because you get more range). So that would be: + | | +---+--+ | l…

What happens to the voltage across the diode when the temperature changes? Looks to me like you've just replaced a calibrated temp sensor with two sensors in series!

Re: Ask HN: What are you working on?

#122

Post by joe_bleau » Tue, Jan 05, 2010, 9:07 PM UTC

jgrahamc wrote: post #2

I am working on making 500 of these: http://www.jgc.org/blog/2008/03/building-temperature-probe-f... for schools in Uruguay.

I'm really surprised that the mic input is DC coupled. That's _very_ odd. But then I've not seen the schematics (anyone got a link?), so maybe it is.

I'd certainly consider a low power rail-to-rail op-amp and dump the 9V batteries.

Re: Ask HN: What are you working on?

#123

Post by jacquesm » Tue, Jan 05, 2010, 9:08 PM UTC

joe_bleau wrote: post #121

jacquesm wrote: post #109

Earlier quoted context omitted.

Have you tried simply raising the ground of the LM 35 by placing a diode in series with the 0 terminal? That way you might just add a single 10ct component and get rid of the problem completely. Just enough to raise the ground of the LM35 above the input sensitivity threshold. One Si diode would probably work, two Ge in series would be slightly better (because you get more range). So that would be: + | | +---+--+ | l…

What happens to the voltage across the diode when the temperature changes? Looks to me like you've just replaced a calibrated temp sensor with two sensors in series!

The temperature of the diode will change right along with the temperature of all the other hardware, it's not as though you'll go out of your way to get the diode heated up.

The way it's drawn is not the way it is built, the diode would normally sit near the computer end of things, not right on top of the sensor.

The thermal drift of the other circuit is at least as large as that of a diode at room temperature, probably a whole lot larger.

Re: Ask HN: What are you working on?

#124

Post by wensing » Tue, Jan 05, 2010, 9:08 PM UTC

Working on an update to http://stormpulse.com that will give us city-level maps and general/severe weather forecasts.

Re: Ask HN: What are you working on?

#125

Post by ivenkys » Tue, Jan 05, 2010, 9:09 PM UTC

ivenkys wrote: post #72

Developing a generic price arbitrage engine making it easier for sellers to track price movements of their products vis-a-vis their competitors. The first release will target sellers selling on Amazon. I should have a private beta by the end of the month.

Just wanted to add , there are 2 features that i am most excited about (at least for the first release):

a) Speed The web front-end and the back-end processing engine have been written keeping in mind processing time, everything is optimised to get data quickly in front of the user.

b) Scripted Rule-based pricing A user can script the pricing engine by specifying rules written in a custom-DSL. My first attempt at doing a proper DSL.

Re: Ask HN: What are you working on?

#126

Post by bradbeattie » Tue, Jan 05, 2010, 9:09 PM UTC

A stateless election web service for more complicated aggregate methods (like Schulze STV): http://vote.cognitivesandbox.com

A simple illustration of a possible use for the service: http://www.modernballots.com

Re: Ask HN: What are you working on?

#127

Post by abstractbill » Tue, Jan 05, 2010, 9:13 PM UTC

Caligula wrote: post #103

Working on web based speech recognition. Have a demo at http://www.speechle.com but its buggy. I learned a lot making it but it gets frustrating at times. Decoding is done using Sphinx.

Flash's "allow" button is hidden for me (FF3.5, OS X): http://abstractnonsense.com/Screen_shot_2010-01-05_at_1.11.1...

Re: Ask HN: What are you working on?

#128

Post by abyssknight » Tue, Jan 05, 2010, 9:13 PM UTC

Working on the house I just bought with my wife. It's the grandest hack I've ever had to do. From crazy 22ft walls of glass that need replaced, a kitchen from the 50's that needs a remodel to the shoddy wiring throughout the house. There's tons to do, and little time to do it in.

This year I start a new position at the company I work for. Hopefully it'll bring more visibility and access to the people who make decisions. There's so much that needs fixing here, and with a little elbow grease I think I can fix it all.

Re: Ask HN: What are you working on?

#129

Post by Vindexus » Tue, Jan 05, 2010, 9:13 PM UTC

http://www.snapproofing.com Proof reading service for college students.

Also working on my BreezyFAQ app for plugging in searchable Frequently Asked Questions to your site.

Site is not live but it works fairly well at http://www.snapproofing.com/faq

Re: Ask HN: What are you working on?

#130

Post by jay_kyburz » Tue, Jan 05, 2010, 9:13 PM UTC

http://np.ironhelmet.com

"Neptune's Pride is a multiplayer game of Strategy, Intrigue and Galactic Conquest!

Neptunes Pride is real-time, but games are played over several weeks. Players log in at any time of the day to check the progress of their fleets, view the results of battles and issue new orders.

Explore, Expand, Exploit, Exterminate.

It's the game you know and love with a twist. A 4x Strategy game with it's complexity striped away to reveal a sophisticated game strategic command and diplomacy.

How will you conquer the Galaxy?"