In my previous post, I designed a 3D printed sensor junction box for my well tank depth sensing project. In this post I solder… a lot.
In my previous post, I finished the Web Service that the ESP8266 uses to upload well tank temperatures (and eventually a depth estimate) to a cloud database. In this post, I turn to the mechanical design of the case for the RJ45 jacks for the 1-wire interface.
In my previous post I described how to use long break-away headers, and started soldering the circuit together. In this post I finish transferring the scale circuit from the breadboard to a protoboard, and do a quick test mount of the circuit on the plywood scale base.
A reminder: I found that the Load Cell Amplifier was (by design) so sensitive to changes in resistance that just touching the resistors on my solderless breadboard caused large changes in the Amplifier output. So I wanted to solder all the parts down.
It’s a good time to recap: This project is a scale that will sit underneath my dog Pippa’s bed, so that I can measure her weight automatically, at night while she sleeps. The project-in-progress is Open Source, at my CurieBLEWeightMonitor Github repository. I occasionally tweet about it (among other things) as @bneedhamia.
In my previous post I covered how to choose matching resistors for the Load Sensor to convert the Load Sensor into a Load Cell that can be wired into Sparkfun’s Load Cell Amplifier. In this post, I nearly finish building the breadboarded circuit and start transferring it to a soldered protoboard.
I recently decided to try out the Sparkfun Arduino Pro Mini 5V board. It has almost all the I/O that an Arduino Uno has, in a much smaller board. It comes without connectors, so you can solder in whatever style connector you need. For my uses, I needed to solder on male headers that allow it to plug into a breadboard.
So I tried out a new way of soldering male header pins onto a board. First I snapped off two 12-long headers from a strip of break-away male headers. Then I plugged those headers into a breadboard and laid the Arduino Pro Mini board over them. To keep the flux and solder spatter from getting into the breadboard holes, I put a piece of paper over the unused parts of the breadboard.
With the pins plugged into the breadboard, the Arduino Pro Mini dropped onto those headers, and the paper protecting the breadboard, I soldered the pins. I then unplugged the board from the breadboard, and used my regular QuadHands to hold the programming pins to the board, because those pins point “up” instead of down.
The result was fine. I did have a little trouble with the solder, but I just need a little more practice, and I need to clean the soldering iron’s tip better.
Next I tested each of the pins. Notice in the picture that I’m using the Sparkfun 5V FTDI breakout to connect the Arduino to the laptop. It works like a charm!
Now all I need to do is decide what to build with this tiny, easily-battery-powered Arduino – whee!
Since my last post about the glockenspiel, I’ve been taking a vacation from my vacation (aka working). Today I turned back to the glockenspiel and wired up the first of the 5 lighted switches.
The hardware is lighted buttons from Sparkfun in various colors, some 4-wire phone cable I bought years ago, and 4-conductor 0.1″ connectors. The heat-shrink tubing keeps the 5 pins of the button from shorting to each other. Two wires run the LED, and the other three make up the button (common, normally open, and the unused normally closed).
I had a little trouble reading the switch: whatever I did, the output was close to ground. After much experimentation, I realized that the pin I was using (pin 52) is used on the Arduino Mega 2560 for part of the SPI bus. Once I moved the input to an unused pin, it worked like a charm, with the internal pull-up resistor to keep the parts count nicely low.
Next I improve the clanking sound with silicone.
I’ve successfully assembled my second soldering kit: The Velleman MK130 ‘3D’ Christmas Tree. It’s a set of blinking LEDs that sit atop a 9V battery… or you can add some long wires and hang it as a Christmas ornament.
At any rate, it was good practice for soldering, and the result is kinda cute. See my YouTube Video of the Kit for the whole experience.
I figure I’m ready to build an Arduino proto Shield next!
Since I’ve been doing Arduino work, I’ve accumulated a few board and Shield kits that I need to put together. I haven’t soldered since college, so I decided to brush up on my rusty skills by buying one of those little electronics project kits: a Velleman MK102 Flashing LEDs kit.
Check out the really, really boring video of the finished board blinking away at YouTube – whee!
The front of the board doesn’t look too bad; only a few parts pulled away from the board a bit:
The back is the real giveaway that I’m a newbie: most of the soldering looks pretty good, but I see a couple cold solder joints, a couple dirty solders, and one pair of soldered points that are a bit too close for comfort – fortunately they didn’t short out.
Not bad for a first effort, and on par with the handiwork on many cheap electronic gizmos you might buy. Next I’m planning to solder one of those little Flashing LED Christmas Trees, which has many more components. Then I think I’ll be ready to have a go at one of the Arduino board kits!