Temperature and humidity measurements are a nice addition to many hobby projects. But [Rajendra Bhatt] makes the point that many of these sensors have a price tag that is well above what most hobbiests are willing to spend. He decided to take an in-depth look at the DHT11 sensor; which you can get your hands on for under $3 if you know where to look.

The four-pin device uses a 1-wire protocol. [Rajendra] discusses the ins and outs of the communications, demonstrating the part using a PIC 16F628. It’s a snap to connect to your project, requiring VCC, GND, and a pull-up resistor on the single data line. We’ve already seen it used on at least one project, and hope to see more of this little guy in your own hacks.

Now we found this part listed on eBay for less than $3 (buy it now price including shipping… how can they do that?). But Octopart didn’t come up with any options. If you know how to get this through traditional parts suppliers let us know in the comments.

[Pyra] was looking for a way to reprogram some ATtiny13 microcontrollers in a SOIC package. He’s re-engineering some consumer electronics so adding an ISP header to the design isn’t an option. He had been soldering wires to the legs of every chip but this is quite tedious. What he needs is an adapter that can make physical contact with the legs just long enough to program new firmware. After looking around he discovered that a PCI socket can be used as a progamming clip (translated). It shares the same pitch as a standard SOIC package but is not wide enough for the chip. He cut out 4 rows of the socket and the section of motherboard it was soldered to. Then he made a cut down the middle of the plastic and bent the two sections apart. The image above illustrates this, but not shown are the eight wires that he later added to connect to the device.

We wonder if this can be adapted to program SOIC parts without removing them from a circuit board. That would be a handy tool for finishing up the LED lightbulb hack.

Check out this visual hardware guide from deviantART member [Sonic840]. It has everything from memory modules, to bus sockets, to power connectors, to an entire array of CPU sockets that have been used over the years. You’re bound to see something in there you didn’t know existed.

[via Gizmodo]