Throw together a temperature logger in minutes

[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.

Adding Fluke 54 II features to a 51 II thermometer

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.

Keep all eyes on your kegerator with this light up gauge cluster

kegerator_gauge_cluster

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.

[Read more...]

Electronic bird house monitoring goes a few steps further

[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.

Refurbishing a refrigerator for fermenting

[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.

Bluetooth temperature module

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?

Skillet reflow controller

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]

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