Lifelong Learning a blog of all the things I've learned about…

30Jul/101

Nursery Room Temperature Monitor

Temperature Monitor Indicating it's too warm

Temperature Monitor Indicating it's too warm

Let me start by saying I found out a few weeks ago that I'm going to be a father. This is my first child and as you can imagine I'm filled with excitement and nervous energy. Both my wife and I both agreed that we wouldn't start actual preparations for the coming baby until the 12th week to ensure all was well (1 in 4 pregnancies end in miscarriage). I just couldn't sit still and wait, I started reading about what to expect, how to care for a newborn, and so forth.

It was while I was reading about SIDS (sudden infant death syndrome) that I saw a few articles discussing the proper temperature for a nursery to help prevent the SIDS. The articles all agreed that cooler was better, ideally between 64 and 74 degrees Fahrenheit.

I was immediately struck by the idea of creating a visual indicator to allow both my wife and I to easily ensure the room was within this range! I grabbed up my Maker's Notebook and starting drawing what I was envisioning. What did it look like, you ask? Keep reading, you'll soon be rewarded with the answers you seek!

My idea was to utilize a diffused RGB LED, an analog temperature sensor (really wanted to expand my working knowledge of the ADC on AVRs) and a frosted glass sphere to create a highly visible temperature indicator. I quickly sorted through my parts bins and found most of what I would need. A quick search on eBay and a short drive to Lowe's provided the rest.

Here's what you'll need to build one yourself:
1. Wooden base, use your imagination.
2. Frosted glass light shade.
3. LM335 Analog Temp Sensor
4. Atmel ATTiny45/85 micro and appropriate socket.
5. Common anode RGB LED (doesn't have to be diffused, you can do that yourself with sandpaper).
6. Two (82 ohm) , one (150 ohm), one (10k ohm) and one (2.2k) 1/4 watt resistors.
7. A 10k potentiometer.
8. One (.1uF) capacitor.
9. A power source. I used an old Netgear router power supply. 5V regulated output at 2.0A.
10. Some wire, heat shrink tubing, Velcro and appropriate soldering equipment.
11. Firmware and schematic.

I typically breadboard all my designs then move them to PCBs once I've worked out all the kinks, but I had recently purchased a mini drill-press and PCB development kit from Jameco and decided the simplicity of this design would allow me to go directly to a DIY PCB (it also gave me an excuse to try my newHad to calibrate the temp sensor using the 10k pot and my Fluke with attached thermocouple.

Once done, I sat down and wrote up the firmware using AVR Studio 4. After a few more hours, I was all set to try it out. And TADAAA! A fully functioning accurate temperature indicator for the new nursery. I'll paint the wooden base once we decide on colors for the nursery!

Just finished holding the sensor in my hand to warm it up. This show the sensor cooling down and turning the LED white.

A few equations that made my life easier and an excellent article to extend your understanding of the ADC in any AVR:
AVR Freaks (ADC For Newbies)
Convert Kelvin to Fahrenheit

EagleSchematic
Title: EagleSchematic (494 clicks)
Caption:
Filename: EagleSchematic.zip
Size: 22 kB
NuseryRoomTempMonitorFirmware
Title: NuseryRoomTempMonitorFirmware (468 clicks)
Caption:
Filename: NuseryRoomTempMonitorFirmware.zip
Size: 3 kB

NuseryRoomTempMonitorFirmware
Title: NuseryRoomTempMonitorFirmware (468 clicks)
Caption:
Filename: NuseryRoomTempMonitorFirmware.zip
Size: 3 kB
EagleSchematic
Title: EagleSchematic (494 clicks)
Caption:
Filename: EagleSchematic.zip
Size: 22 kB

Filed under: AVR, Electronics 1 Comment
19Jul/100

Tasty Home Medicine

Today, I decided I would try my hand at a simple Irish home remedy that turned into a popular soft drink. GINGER ALE! Ginger ale was used some time ago to treat anything that ailed you but now thanks to John McLaughlin, it's more commonly associated with a refreshing soft drink.

Ginger has long been used to help settle upset stomachs and ease nausea, it's these proposed properties that really made me want to give it a try. My wife has been suffering from nausea quite badly lately and I thought this would be a fantastic solution (if it works). It's all natural and quite easy to make.

Here's my recipe for Ginger Soda:
• 2 Cups Fresh cut ginger (slice into about 1/8 inch slices)
• 2 Cups filtered water
• 2 Cups white sugar
• 1 tsp Pure Vanilla Extract
• 2 tsp Dry Ginger Powder (not required but adds to the zippyness)

Combine the ginger, sugar and water and heat until simmering. You'll simmer the mix until the liquid has reduced to about 1/2. It'll be syrupy in consistency. Add the vanilla and dry ginger powder and stir well. Remove from heat and strain mixture. Let the syrup cool to room temperature and then add about 3 tablespoons syrup to 16 ounces soda water (this will vary on individual tastes), stir well and enjoy! If you want, you can add a bit of fresh Mint and a squeeze of lime to zest it up a bit!

But WAIT! Don't throw away that ginger! It will make a fantastic treat and here's how. Take the cooked ginger from the recipe above and mix it well with 1 cup white sugar. Make sure each slice is liberally coated with sugar.  Place the coated ginger slices on a cookie tray evenly spaced out and put in a preheated oven at 225F. Let them dry for about 3 hours in the oven, they should be dry but still chewy! Yum-O!

Ginger slices ready to simmer.
Ginger slices ready to simmer.
Ginger ready to go!

Ginger ready to go!

Candy ginger ready to dry

Candy ginger ready to dry

Candied Ginger

Candied Ginger

Filed under: DIY Projects No Comments