The team over at the Louisville Hackerspace LVL1 is not going to be outdone when it comes to collecting environmental data. They put together this Frankenstein of sensor boards that lets you collect a heap of data showing what is going on around it.

At the center-left a small Arduino clone is responsible for collecting the data. Data storage is not talked about on their write-up, but if that’s an ATmega328 chip you should be able to work out an easy way to store data on the 1k of internal EEPROM. If that’s not enough, there is an I2C bus included on the board making it easy to add a compatible EEPROM.

The sensor on the bottom left should look familiar. It’s a DHT11 temperature and humidity sensor we’ve seen popping up in projects lately. But wait, there’s also a TMP102 temperature sensor; but that’s not the end of it. A BMP085 pressure sensor also includes a third temperature sensing option. Want to see when the lights go on in the room? There’s a CdS sensor and a TSL230R Lux sensor for that. An op-amp circuit can measure the sound level in the room via one of the Arduino’s ADC pins. And finally, an RTC board is used for time stamping the data.

Obviously this is overkill, and we’re sure it’s meant as a test platform for various sensors. All of them have been mounted on the protoboard and wired up using the point-to-point soldering method.

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.

We love the extra touches that [Andrianakis Haris] added to his two-zone electronic thermometer. It includes features that you just wouldn’t find on a mass-market commercial product because of issues like added cost. For example, you can see that the PCB juts up above the LCD display, allowing the module to be mounted on a pair of screws thanks to the keyhole shape that was drilled in the substrate. I increases the board size greatly, but on a small hobby run this won’t usually affect the price of the board depending on the fab house pricing model.

The design uses an ATmega8 microcontroller to monitor sensors in two different places. There is an onboard LM35 temperature sensor for monitoring the space where the unit resides. A remote sensor module uses a DHT-11 chip to gather data about temperature and humidity. That sensor is wired, but there is one wireless option for the device. Data can be pulled down from it via an optional Bluetooth module which can be soldered to a footprint on the back of the board.

Check out the video after the break to see temperature readings pulled down wirelessly.

[Will] wrote in to share a useful add-on he designed for the ChipKIT UNO 32, a 12-port temperature sensor board.

Constructed for one of his customers, the shield accepts any 2-wire 10k thermistor sensors, outputting the readings to a small LCD screen. The screen is supported by some code put together by his associate [crenn], but you are not limited to solely displaying the temperatures there. Since this module piggybacks on top of the ChipKIT the same fashion as any standard shield, you clearly have the ability to use and manipulate the data at will. With 12 ports on board this would work well for a house-wide temperature monitoring system, or perhaps in a complex brewing setup.

Both the temperature shield and LCD boards have been released under the Open Source Hardware License, so you can easily build your own if you have the means, though [Will] has a few extras he’s willing to sell if you need one quickly.

[Rajendra] found an easy way to make a USB temperature logger. He already had a USB to UART adapter that takes care of the heavy lifting. On one end it’s got the USB plug, on the other a set of pins provide a ground connection, 3.3V and 5V feed, as well as RX/TX lines.

To get the hardware up and running all he needed was something to read a temperature sensor and push that data over the serial connection. An 8-pin microcontroller in the form of a PIC 12F1822 does the trick. It runs off of the 5V pin on the USB-UART, and uses the ADC to get temperature data from an MCP9701A sensor.

The sample rate is hard-coded into to the PIC’s firmware, but adding a button, or coding some serial monitoring could easily make that configurable. [Rajendra] used Processing to write an app which displays the incoming temperature info and uses the computer to time-stamp and log the inputs. We could see this as a quick solution to tracking wort temperature during fermentation to make sure your beer comes out just right.

The difference between Fluke’s 54 II and 51 II thermometers is the addition of a second channel for dual temperature sensing, and buttons which control data logging. Oh, and an additional $150 in price for the higher model. [TiN] was poking around inside and with the help of some forum members he figured out how to unlock additional features on his low-end Fluke temperature meter. You can do the same if you don’t mind cracking open the meter, sourcing and soldering most of the components seen above, cutting holes in the case for the buttons, and hoping it still works when you put everything back together.

It seems that Fluke designed one full-featured unit and watered it down to fill a hole in the lower-priced market just like some other testing-hardware manufacturers (Rigol’s digital storage oscilloscopes come to mind). But the MSP430 P337I in this meter cannot be reflashed, so this would most likely be unhackable hardware if the firmware for the two models is different. After some intensive study of the PCB layout [TiN] found a set of resistors which seemed to serve no external hardware purpose. They do connect to the microcontroller and together they create a two-bit code. He was able to get pictures of the four different hardware models and work out which resistor combinations identify the different meters. Now he can get the firmware to believe it is operating a Fluke 54 II, the rest is just putting the correct passive components onto the unpopulated locations.

We think the quest is what is of interest with this hack. [TiN] did an amazing job of photographing and writing about each step in the process. We’re unlikely to try this ourselves but loved reading about it.

A few years back [Evan] built a kegerator from a mini fridge and was quite happy with his new beer chiller. Like many of us do, he started thinking up ways in which he could improve the project as soon as it was completed. While it took a couple of years, he recently got around to adding the temperature and capacity gauges he always wanted.

He added a temperature probe to the refrigerator, and then constructed a pair of tools that he could use to measure how much beer was left in the keg. The volume monitors include a scale built using a pair of pressure sensors from SparkFun, and a flow sensor installed in the beer line.

[Evan] scored an old Chevy gauge cluster and cleaned it up before installing a pair of analog meters which he used to show the keg’s temperature and “fuel” level. Since he feels no project is complete without some LED love, he added a few of them to the display without hesitation. The LEDs calmly pulsate when the keg sits idle, but spring to life and begin flashing when the flow sensor is activated.

As evidenced by this pair of keg monitoring systems, we think that you can never have enough information when it comes to your beer stash, so we really like how this project came together.

Be sure to check out his kegerator’s gauge cluster in the video below.

[Stephen Albers] offers his avian friends a lot of extras with this electronically monitored bird house. This will not only give you a look at what’s going on inside, but provide a source for several other bits of data as well.

First off, a camera has been mounted to the underside of the roof. This looks down on the nesting area and features night vision so that you can peek in any time day or night. He used a WiFi webcam that operates separately from the other electronics.

With the remainder of the setup he is able to harvest temperature and humidity data inside, temperature outside, force on the bottom of the house (although this turned out to be less useful than anticipated), and a in-and-out count for the doorway provided by an IR transmitter/receiver pair.

This offers quite a bit more than the last bird house project we saw. That one also left a lot to be desired as far as protecting the electronics. [Stephen] didn’t skip on that kind of protection. Most of the electronics are housed in an acrylic chamber in the base of the house. The sensors find themselves nestled in plastic enclosures, although some work needs to be done to ensure that the temperature and humidity sensors will still function correctly with this setup.

[Mikey Sklar] wrote in to show us how he refurbished a neighbors useless refrigerator as a fermentation chamber. [Mikey] is a fan of making breads, kemchi, yogurt, and tempeh. To make these, it helps to have a completely controlled temperature for them to ferment in. [Mikey] developed a temp controller for this in the past, but had to either build a control box or use a giant chest freezer.  This is not optimal for limited space, such as a kitchen. He got lucky when a neighbor tossed a wine cooler into the trash. These little coolers are perfectly sized for a kitchen and even have a glass front so you can keep an eye on what is going on inside without having to open it and effect your temps. [Mikey] ripped it open, replaced the peltier cooler with a large heat lamp and his temp controller. Since he was making yogurt with this one, he needed only to heat it. The final product turned out pretty effective.

Wanting to know the outside temperature, [Jamie Maloway] built his own temperature sensor that can be read with a Bluetooth device. Let’s take a tour of the hardware above from right to left. There’s a linear voltage regulator with two filtering caps and a terminal block to attach a 9V battery or other power source. Next there’s an 8 MHz crystal and it’s capacitors, followed by a programming header on top and a 1-wire temperature IC, the DS18B20 we’re all familiar with hanging off the bottom. These both connect to the 8-pin PIC 12F675 that drives the system, and transmits using a Bluetooth module from Sure Electronics. Since this is using a serial protocol and transmitting ASCII data, it can be read using an automated script, or simply by using a terminal program.

Now, who’s going to be the first to get rid of the battery and leech off of the mains through inductance?

Using an electric skillet to reflow surface mount circuit boards is a popular alternate use for those kitchen appliances. The real trick is monitoring and controlling the temperature. [Mechatronics Guy] built his own skillet temperature controller using a thermistor, a solid state relay, and an Arduino.

He was inspired by [Ladyada's] work which used a servo to adjust the temperature dial on the skillet’s power supply. This started by attaching the thermistor to the bottom of the skillet using JB weld. since this area will be heating up he also attached a terminal block for connecting the feed wires as the heat would melt any solder joints. Those wires travel back to a control box housing the Arduino and solid state relay. To gain finer control over the heating element the relay is switched on and off, resulting in low-frequency Pulse Width Modulation, which should help maintain a consistent temperature better than just turning the temperature dial on the cord.

Pair this up with the vacuum tweezers hack and you’re on your way to a surface mount assembly line. If you want to see this process in action check out this post. It goes from stenciling, to populating, to reflowing in a toaster oven.

[Thanks Rob]

Here’s an interesting take on augmenting a car’s dashboard. [Daniel] is using a button blank to house a 1″ OLED display in his Jetta. It shows auxiliary data such as boost pressure and several sets of temperature readings. The display itself has a tiny little circuit board with a PIC 24 to drive it. A larger board, seen above, collects the temperature data from some sensors that [Daniel] added as part of the hack. There are some pictures of the installed display inside of the dark car and it looks really easy to read. It also sounds like there’s some dimming functionality built into the firmware. This is the easiest way we’ve seen to add a display to your dashboard as it just requires you to pop out a button blank, rather than disassembling the entire console or patching into what’s already there.

[Mikey Sklar] finds himself in need of a temperature regulated refrigerator for fermenting foods like yogurt, kimchi, bread, and beer. After some testing he found that by building his own controller he can get a chest freezer to outperform an upright refrigerator at this task by 2-to-1.

The controller is based around an ATmega48. It includes a remote temperature sensors which you can see connected to the lower left header in the image above. On the back of the board there’s a relay used to switch the freezer’s power on and off. [Mikey] is selling a kit but the hardware and software for the project are both open source so build it yourself if you have the know-how.

A chest freezer is a great place to store Cornelius kegs… we’ll keep our eyes open for one.

We’re rather surprised at how popular it has become to build your own motorcycle computer. [Mario Mauerer] tipped us off about his shiny motorcycle computer (translated) for his Yamaha XTZ 750. It uses an ATmega644 microcontroller to pull a variety of data together and display it on this white LED backlit display. He connected a flow meter to the fuel line to monitor gas consumption. Oil temperature is captured by inserting a brass tube (containing the sensor) through a hole in the oil cap and soldering it in place. Water temperature is gathered by measuring the external temperature of one of the cooling lines. [Mario] uses a rotary encode with a click function as the control interface device, and a battery backed real time clock keeps time.

A quick look at the PCBs tells the tale of good circuit design. But we do wonder about catching the reflection of the sun in that shiny bezel.

[Muth] added an auxiliary display to his motorcycle instrument panel. He started out prototyping with a PIC 16F877A which he used to access information through the ECM diagnostic connection. Once he had that working he found this tiny display which fits perfectly between the speedometer and tachometer. There’s a short demo after the break where you can see a past-30-minute history of the Adaptive Fuel Value and the engine temperature as well as a secondary information screen.

This is another nice addition to our collection of vehicle displays, scooter controllers, gear indicators, and motorcycle computers.