Welcome back everyone! We have a lot of new products to talk about AND a really cool demo that some of our unpaid interns loved. Check it out.
We have a lot of new stuff to talk about this week, so let's dive right in and see the goods.
Load cells are pretty cool and an easy way to measure weight, but they can be a bit tricky to use without the right hardware. The SparkFun Load Cell Amplifier is a small breakout board for the HX711 IC that allows you to easily read load cells. The HX711 uses a two wire interface (Clock and Data) for communication. This can be handy for creating your own industrial scale, process control, or simple presence detection. But you're probably going to need some load cells to use with your fancy new amplifier, right?
A load cell is a physical element (or transducer if you want to be technical) that can translate pressure (force) into an electrical signal. There are a few different types of load cells out there. The first two that we have are bar-type load cells. They are long bars that are good for measuring up to 10kg of weight. The straight bar is slimmer whereas the wide bar is, well, wider. They work essentially the same way, you just need to pick the form factor that works best for your application.
If you want to read more on load cells and how to use them, check out our new tutorial, Getting Started with Load Cells.
Another type of load cell is a disc-type. These are circular and measure a load applied directly to the top of the cell (as opposed to way bar-type load cells work). This makes them a lot easier to use, requiring less mechanical design. We have two disc load cells, one that can measure 200kg and one that's good up to 50kg.
If you've ever taken apart an electronic bathroom scale, you will see that there are 4 load sensors inside. The SparkFun Load Sensor Combinator is a simple PCB that combines four load sensors into a standard 4-wire wheatstone configuration. You can then connect this to the amplifier above. The combinator board also includes a footprint for the DS18B20 one wire temperature sensor. This allows the user to gather the temperature of the scale in case there is a large variance between the scale and the amplifier.
The WAV Trigger is a unique high-fidelity polyphonic audio player with surprising capabilities. Supporting up to 2048 uncompressed 16-bit, 44.1kHz wav files – the same quality as an audio CD – the WAV Trigger can play and mix up to 14 stereo tracks simultaneously and independently, with very low latency. This new version of the WAV trigger has the newest firmware that allows for more tracks to fit on the microSD card, MIDI pitch bend, and real time sample-rate control.
The Chibi Lights Starter Kit from Chibitronics is an interactive kit designed to introduce you to the world of paper circuits. Inside each Starter Kit is everything you need to set up simple LEDs, switches, and sensors with only a bit of knowledge on how electricity works and a little ingenuity! Included in each kit are 12 individual LED stickers (6 white, 2 each of red, yellow, and blue), a 5 meter roll of copper tape to run conductive lines to your LEDs, two CR2032 coin cell batteries to power your circuit, two small binder clips for holding your battery in place, a swatch of conductive plastic to help create a simple sensor, and finally a Circuit Sticker Sketchbook to provide you with an introductory guide to using circuit stickers.
Have you ever needed a cheap way to activate something from across the room? Infrared remotes are still the cheapest way to wirelessly control a device. We have designed the remote to be small, very simple, and low-cost. The IR Control Kit includes a simple IR remote control, a battery, and IR receivers and emitters to get you started playing around with IR control.
Phew, that's it for this week. Keep in mind that AVC is only a week away! Be sure to check out the workshops we'll be holding. Thanks for reading and check back next week for more new goodies!
Slick flick of the knife. Doing it off camera makes it seem even more sinister.
In the background of these videos is that cool looking sparkfun sign with individually controlled LEDs (something like WS2812/B). It changes one LED at a time from red to white, and when it gets though it repeats, changing to red again. However, the data/buffer stream seems to be off sync with the time cycle. It should update in the order 1R 1G 1B short delay 2R 2G 2B short delay 3R 3G 3B ... short delay nR nG nB long delay (start the cycle over with the other color). However, the last LED's blue channel doesn't get updated until after the long delay (when number 1 gets updated). It ends up being in the order nB 1R 1G 1B short delay 2R 2G 2B short delay 3R 3G 3B ... short delay nR nG (nB is NOT updated yet!!!) long delay (start the cycle over with the other color, beginning with nB). It is apparent in that after going from red to white, the last LED is yellow, and when going from white to red, the last LED is purple. It doesn't seem to do it always, but fairly regularly. Does anyone ever intend to fix it?
Steganography. But I've said too much.
After going back through 7 months of New Product Posts, I pieced together enough video to figure out the secret message. It repeats over and over - eat more pie.
Is there a prize?
Honestly that was my first thought. I decided is was very unlikely though. The changing camera angles make it only occasionally visible. Furthermore, most video has been edited to be played back in a non-chronological manner, and most video has been cut (I'm assuming this is no exception). It seems unlikely for there to be a discernible message hidden.
so, what if you want to measure up to say 100-200 grams, and resolution of 1 or less grams?, seems like all load cells like this are around 5-10kg and up :(
Is there a plan to offer the load cell amplifier with some kind of shielding? With the very small changes in voltage associated with load cells and strain gauges, shielding is very important to get an accurate sensor reading.
The food feeder is pretty cool, but shouldn't all that exposed wire and parts be cover so the dogs don't kick something loose?
In a permanent installation - definitely. This really was just for the purpose of the demo. Shawn doesn't even own a dog.
I know. And it makes me so sad :(
You can borrow mine for short periods of time. :)
Remember when he ate my goldfish, and then you lied to me and said I never had any goldfish. But why did I have the bowl Bart? Why did I have the bowl?
That's cold, man.