Cold Fusion, LENR and NASA

Screen shot 2014-09-07 at 5.06.35 PM


I stumbled over the document that is the subject of tomorrow’s blog post (sorry –  an obnoxious tease),  poking around the web looking for documents on LENR (low energy nuclear reactions).  LENR is now the preferred name for the research that grew out of what is still called “cold fusion.” Cold fusion and LENR are used somewhat interchangeably now, although people realize that “cold fusion” is now a pejorative. This may change back (be changing back now?)  if/when LENR reactions are confirmed and scientists begin to own the term, even though it may not completely and accurately describe the phenomenon.

After lots of reading about cold fusion (mostly for fun), including experiments, scientific papers and conference reports, my (completely unqualified – because I don’t have a degree in physics) take on the cold fusion / LENR field is summarized below.

  • The effect is real, having been confirmed by qualified, conservative academic researchers hundreds of times.
  • The phenomenon is new science and so is not going to be explained by the standard model,
    although this is controversial, as no theory now convincingly explains all of the experimental evidence that cold fusion researchers have uncovered.
  • Researching the LENR phenomenon is still verboten in academic physics departments, and graduate students are not yet encouraged or allowed to pursue the field, although:
  • Things are starting to change as,  MIT has run a short course on cold fusion in the winter break, for two years running now. You’ll note from the link that the sponsors are Electrical Engineering and Computer Science, and not the Physics Department. Members of the MIT Physics Department were responsible for spiking claims about cold fusion back when it was originally announced in 1989, and there is still lots of bad blood between the groups of scientists. The Physics Department also has some large grants from the government to study hot fusion, a field that continues to make very slow progress, at the cost of billions of dollars spent.
  • Some LENR researchers have claims of commercial scale power generation (e.g. 1 megaWatt),
  • Which has attracted venture capital, although;
  • Rock solid technical confirmation of the technology is yet to be made public.
  • Patents and proprietary efforts are heating up including one by STMicroelectronics, a name that I expect a fair amount of people who are reading this blog will recognize, as they make sensors for Iphones, and motor drivers among lots of other interesting chips.
  • On the downside, the field attracts some cranks and wishful thinkers, as one might expect with a technology that has been repressed, but also promises many social benefits such as the generation of a fair amount of energy from common materials without a lot of polluting or toxic downside.
  • NASA apparently also believes that there is something to LENR and is putting a bit of money into research, and including it in plans for possible future spacecraft. NASA is all about the future and also all about contingency planning so this may not be saying too much.

Anyway I’ll skip the links and leave you to the “tender mercies of your own Internet Research” as my undergraduate mathematics professor might have said, had the Internet been invented yet. Google LENR and you too can be confused and rewarded. Tomorrow – The Pentagon’s view of 2025.

By Paul Badger on September 7, 2014.

4 x 16 LCD character display


This is a very high quality 4 x 16 character display removed from new equipment. We bought them on a lark for their ABS boxes, and eventually we will spin up some products for the boxes. In the meantime they are taking up space in the shop and we’d like to move a few out. $5.00.

There are a couple more pictures on the product page.  We found that it works great both with the Arduino LCD library and with our LCD117 Serial LCD drivers.


  • Overall: 3.44″ x 2.37″             87.4mm x 60.2mm
  • Bezel: 3.15″ x 1.57″           81.7mm x 39.8mm
  • Display Area:   2.41″ x .982″   61.3mm x 24.9mm
  • Blue-Black letters on gray-green screen
  • There is no backlight.

In the shop here.

By Paul Badger on August 6, 2014.

A Stereo Audio Amplifier





The Modern Device Stereo Amplifier breakout board is a minimal Stereo Amp designed to amplify small projects, such as amplifying the Fluxamasynth Shield, or an Adafruit Wave Shield for personal use in fairly quiet spaces. It is probably not loud enough for a good dorm-room dance party. It is also great for increasing the volume level of your Arduino or other micro-controller when used for musical projects.

A few words about the demo. We are using the Arduino just for a convenient source of 5 volts to power the amp. The output is directed to two  of our 8 ohm loud-speakers inserted into coffee cups for better amplification. We specifically bought a size that could be used with a coffee cup as a speaker enclosure. This was a trick I didn’t originate but picked up from one of my resourceful students.  For this project, we found that cutting a hole in the back of the cup produces a warmer sound, as opposed to leaving it covered. The left and right potentiometers control the volume of the left and right channels as you would expect.

As in the mono version of this amplifier, we have used real analog volume controls to make adjustment of volume easy. While it can be useful to have software control over output volume, it can also be useful in many situations, to have physical control over output volume. The example I sited in my post on the mono amp is still the first and best one that comes to mind. You have a piece installed in an art gallery and you want it to be heard during the opening of the exhibit. Typically art galleries are very crowded during openings, people have been drinking and the volume is loud. Afterwards there are typically between 8 and 0 people in the gallery, with much lower sound levels. Being able to physically tweak the volume is an easy way to set appropriate volume is very useful. Many other situations exist, even with digital sound, where a simple potentiometer is more effective than two buttons with some kind of “up-down” digital interface.

The Modern Device Stereo audio amplifier breakout board uses the LM4992, one of National Semiconductor’s “Boomer” amps. It uses what in the industry is referred to as a “bridge-tied load”. This is an efficient system that increases the total amount of power available to the speaker with low-voltage systems. It also eliminates the need for an output capacitor, (like in the LM386) which tends to be bulky and can limit the low-end response. It has a shutdown pin to put the chip to sleep, just in case you’re trying to build a super low-power microcontroller application that spends most of its time sleeping.

All this in a really small package.  Here are some specs with a 1khz signal.

Power Out VCC THD & noise Load (speaker ohms)
1W 5 volts  .1% 8 Ω
.4W  3.3 volts .1% 8 Ω

This is not quite CD quality sound, since this chip was designed for cell phones, but then neither are most of your other electronic appliances (such as phones and mp3 players) these days. Pop music still seems to be doing fine.

Ships with a two terminal blocks,  a 4 pin male header, and two 200K pot which all not soldered onto the board. All other parts are assembled and tested and ready to go.  It’s in the shop here.

By Britton on July 28, 2014.

Rev P Wind Sensor Data

The Modern Device wind tunnel outfitted with a pitot tube and temperature sensor.

We wanted some more “objective” methods to confirm the numbers on our growing collection of anemometers, so we naturally thought about pitot tubes. This is the way that aircraft tell their airspeed. I don’t know how much they get used anymore, but the great virtue of a pitot tube is that it can be entirely mechanical, although that would of course depend on the gauge that is used to translate the pitot tube’s pressure into a number.

The pitot tube actually has two connections. The “high side” connection is exposed to the oncoming air and generates a positive pressure. The “ambient” connection, takes into account any static pressure in the system. The two lines are then read differentially, similar to a differential connections for an op-amp, so that the output is the high side pressure minus the ambient pressure.



Isn’t this a wonderful looking set of gauges? These are called “Magnehelic” by Dwyer instruments. They are totally analog (although an electronic one is on top) and are hooked up to the pitot tube with small rubber tubes.

Here is some raw data from the Rev P Wind Sensor at 4 different temperature points.


It would be very nice if static pressure was just proportional to wind speed, but few things in life or in physics are so simple. The pressure generated is dependent on the density of the air, which makes sense if you think about it. The density in turn, is dependent on barometric pressure, temperature and humidity.

Here’s a graph that shows the temperature dependency.

Velocity vs Temp.png001

So I implemented the math to correct for temperature and barometric pressure. One little hiccup was that “Absolute Temperature” was denominated in the little-used Rankine scale (F + 460). Once I entered the correct values for temperature, some wind speeds that looked very plausible came out the other end of my Excel spreadsheet, whose chart looks like this:


A couple of conclusions that I’m drawing is that at lower air speeds, the ambient correction circuit in the Rev P wind sensor is doing an admirable job, for some reason at higher wind speeds there is still some correlation between output and ambient temperature. It’s curious that the higher temperatures are reporting greater output, because normally one thinks of it taking more energy to get cold air up to temperature.

My current focus is on the ambient temperature correction circuit. The thermistor doing ambient correction is a 10k which is not by my choice. I would have desired a much higher value, but 10K was the highest value available in the thermistor line that I am using. The 10K thermistor dissipates about 3mW which is enough to raise its temperature almost 1 degree K, according to the datasheet. (Datasheet is 4mW/K). This would tend to be velocity sensitive also as at higher wind speeds the self-heating would be swamped by the power of the wind speed to enforce the ambient temperature. It’s just a hypothesis at this point.

Another hypothesis is that the “active” (heated) thermistor and the ambient sensor, just don’t track each other perfectly, leading to some variation over temperature. Indeed I would be shocked if there was no variation over temperature. I can cure the self-heating problem fairly easily, but only a lookup table will compensate for the variation in sensor response over temp, and that is the direction in which we are heading.

The new wind sensors are in the shop here:

By Paul Badger on June 26, 2014.

New Rev P Wind Sensors


In addition to working on our wind tunnel, we’ve been developing new wind sensor designs. Rev P is not a new version of our rev C wind sensors that we have made for several years. It might have been better with a new name, and may eventually get one, but for now it’s “Rev P”.  “P” stands for PTC or Positive Temperature Coefficient thermistors. The difference between NTC and PTC is as follows: NTC thermistors have smaller resistance as they get hotter, whereas PTC thermistors exhibit a larger resistance when they get hotter.

Why new thermistors? The PTC thermistors track each other more closely, and the ambient temp thermistor in the new design actually is part of the Wheatstone bridge, instead of just sensing ambient temperature, as in the Rev C sensor. The part is also available in a higher precision (1%) than the 3% thermistors in the Wind C sensors. The rev P thermistors are supposed to be more stable than the parts in the Rev C, with excellent values for maintaining their values after a year of being heated.

As you can see, the potentiometer has gone away, and the only wind speed output is the voltage output of the wind speed sensor. We have also added a real temp sensor, that is not dependent on the supply voltage. Everything would be great in wind sensor land IF I could buy PTC thermistors in the values I want. The chip I’m using only seems to be available in 100 ohms, which ends up being around 120 ohms by the time it gets up to working temperature. Consequently, to get enough power to heat the chip up, it requires a higher voltage than the Wind C sensor, which is slightly inconvenient. Right now the sensor requires 8 volts, which probably means a readily available 9 volt supply. We will bring out the next version very quickly that will have a boost regulator so that the sensor will run well from five volts.

Current draw is around 40 mA but this goes up at higher wind speeds, which one would expect, since it requires more power to keep the sensor hot at higher wind speeds.

Another feature of the sensor that we have been experimenting with is the non-standard mounting of the chip, with no pcb behind it. This goes a long way toward making the sensor omnidirectional. The chips are only coated on one side so there is still some built-in asymmetry in the sensor’s directional response that probably can’t be compensated out, without using two sensors. We’ll also get that characterized next week.

We’re still gathering data in the wind tunnel on this beauty and should have curves (at least from 25 to 40 degrees) and an Arduino sketch early next week. They’re already in production and in stock.

The new wind sensors are in the shop here:


By Paul Badger on June 6, 2014.

The Modern Device Current Sensor at 3.3 Volts

When we designed the current sensor we noticed that the hall effect sensors were rated only for a 5 volt supply in the datasheet, so we didn’t know what kind of performance we would get, if any, with a 3.3 volt supply voltage. So while we were doing the calibration research, we gathered some data at 3.3 volts. We didn’t plug in as many different loads as  with the 5 volt sensor but as you can see from the graph below, the output is very linear, once you get past the very low power “hook” on the left end of the curve, which is due to the “noise floor” from the amplified sensors.


So the good news is that the Current Sensor will work fine on a JeeNode or other 3.3 volt microcontroller. One caveat is that the sensor’s saturation point (maximum reportable value) is also a bit smaller than the 3.3 volts supply,  because the output is governed by the topology of the op-amp peak detector.

Screen shot 2014-05-07 at 3.53.35 PMThe peak detector works with diode D1. The op amp IC1D cannot produce a voltage higher than 3.3 volt supply voltage so the maximum value for the peak detector output at IC1C (pin 8) is going to be 3.3 volts minus the voltage from the diode drop, which in this case is about .2 volts because we used a special schottky diode to try to minimize the diode losses.






By Jeffrey Blum on May 7, 2014.

Current Sensor – A Quick Calibration Method

Our last post concerned the Current Sensor and how to calibrate it to measure the amount of power being drawn through an AC line. That process involved gathering data and plugging it into a spreadsheet program, validated the sensor and showed that the voltage output of the sensor was very proportional to the power draw in the wire it was sensing. It occurred to us that if the output is linear, then only two points are really required to define a straight line. Thus, it would be fairly easy to develop a quick (but perhaps a bit less accurate) calibration by entering only two data points total.

So we developed a second current sensor program, shown below. To make this one work, all you need is two appliances with different power draws, ideally one around 20 to 200 watts and the other closer to 1000 watts. Measure the voltage generated by the current sensor for those two loads individually then substitute your data points in for V1, P1, V2, and P2, and you are done. The sensor is calibrated. As long as it doesn’t get bumped on its line cord, it should maintain very faithful calibration.

The one caveat is that you should make sure that the sensor is not saturating (hitting its maximum) on your higher current draw, so make sure the output voltage is under 4.3 volts (if powered from 5 volts). The analogous value (highest voltage without saturation) when powering from 3.3 volts is 2.6 volts.

That’s it! The program takes care of finding the equation for you really quickly at the expense of only using two data points, which means less accuracy. But as I said earlier, that might just be enough for you. Enjoy!

  Reads a Modern Device Current Sensor on pin 0, converts it to voltage,
  calculates the power, and prints the result to the serial monitor.
  Attach the V_OUT pin of the Current Sensor to pin A0, and V_IN and GND
  to +5V and ground respectively.

  This example code is in the public domain.

//You'll have your own values for these constants

#define V1 0.577  // voltage of first data point
#define P1 225    // power of first data point
#define V2 2.91   // voltage of second data point
#define P2 1000   // power of second data point
float SLOPE;
float Y_AXIS_CROSS ;

void setup() {
  //Find SLOPE and Y_AXIS_CROSS for quick calibration
  SLOPE = (P2 - P1) / (V2 - V1);
  // initialize serial communication at 9600 bits per second:

// the loop routine runs over and over again forever:
void loop() {
  // read the input on analog pin 0:
  int sensorValue = analogRead(A0);
  // Convert the analog reading (which goes from 0 - 1023) to a voltage (0 - 5V):
  float voltage = sensorValue * (5.0 / 1023.0);
  //Calculates power from voltage
  float power = voltage * SLOPE + Y_AXIS_CROSS;
  // print out the value you calculated:
By Jeffrey Blum on May 5, 2014.

Calibrating the Modern Device Current Sensor

Current Sensor with PlugModern Device sells a handy Current Sensor that can measure the amount of AC / alternating current flowing through a cord attached to it with the miniature zip ties we include with the sensors. While the sensor has an analog output and is extremely easy to use to check if an appliance is ON or OFF, we thought we would both validate the sensor and write a tutorial to allow users to put some hard numbers to the analog output. This would allow users to confirm the actual amount of power being drawn by a device.

A Brief Bit of Math
The chips on our sensor actually measure the amount of current flowing through the wire, which is why it’s called a Current Sensor (technically though they measure the magnetic field that is created by the current flowing in the wire, but the magnetic field is also proportional to current).

Luckily there’s an easy formula that equates power (P) to current (I) multiplied by voltage (V). Furthermore, we know that the voltage coming from the wall is constant (around 120 in the United States and 230 in the EU), which makes power proportional to current. In other words,

P = V * I, therefore P  is proportional to I (current) for constant V (voltage)

Perhaps to make things more confusing, the output of the sensor is itself a voltage, although it represents (is proportional to) the sampled current.

Got it? Good, moving on.

The Setup
A standard power strip is a convenient way to test and calibrate the Current Sensor. To start, make sure there are no active loads attached to the power strip (you might as well unplug everything from the power strip, just in case). To set up the test, attach the Current Sensor to the surge protector’s cord as shown above and tighten the zip ties snugly (the sensor should not be able to rotate around the cord unless you physically touch it). For our test, we also set the gain potentiometer on the sensor to its lowest possible setting (all the way counter-clockwise). Connect VIN and GND on the Current Sensor to +5V and GND respectively on an Arduino (we used one of our 3-wire cables as a connector). Finally, attach a voltmeter to the VOUT pin on the Current Sensor and another GND pin on your Arduino. Even though nothing’s plugged in, you should still see some small voltage. This is noise from the sensor, because the sensor is so highly amplified. This low voltage represents the noise floor or the zero current level of the sensor.

Arduino Leonardo, multimeter, and a surge protector with loads

Arduino Leonardo, Multimeter, and a surge protector with loads

Now plug in a medium level load (anything between 100 and 400 watts will do) so you get an actual reading. If the voltage doesn’t increase, check your connections and power supply. If you rotate the sensor around the cord, you’ll notice that the voltage changes as the angle of the sensor on the cord changes. If you are more concerned with sensing small to medium loads – say 5 to 600 watts – you will probably wish to set the sensor angle to its most sensitive angle (highest voltage) so the sensor is more sensitive to smaller changes in current.

If you expect to be sensing large loads – we’re talking 600 to 1500 watts or higher – you may wish to use a sensor angle corresponding to a lower voltage so the sensor will not saturate (hit its maximum value – which is around 4.4 volts)  before you reach the maximum desired load to sense. In this case, you may wish to plug in your maximum load now, and rotate the sensor until you observe an output value somewhat below 4.4 volts.

Note the angle of the current sensor relative to the cord

Note the angle of the current sensor relative to the cord

Gathering Data
Once you have decided on a sensor angle, it’s time to collect data. You’ll need a few loads with known power ratings that span the range of power you expect to encounter. Look on the labels of the appliances your are using; in the United States, appliances are required to have their power draw printed on the label. For our test, we used the following loads (you don’t really need this many):

Load Power (W)
Lamp 18
Lamp 43
Lamp 100
Heat Lamp 125
Electric Radiator (Low) 600
Electric Radiator (Medium) 900
The three lamps (different bulbs), heat lamp, and radiator we used to calibrate our current sensor

Our motley crew of loads, three lamps (different bulbs), heat lamp, and the radiator we used to calibrate our current sensor.

Start gathering data by recording the voltage level with no loads at all. Then, record the voltage when each individual load is turned ON by itself. If you want more data, try measuring the voltage when different combinations of loads are turned on (the power ratings simply add together). We took a variety of measurements to prove our point in this tutorial; you should only need 5 or 10 total. That said, the more data you collect, the more accurate your calibration will be. There is an assumption in this that the nameplate ratings of the loads that you test are also fairly accurate.

Be careful NOT to move the current sensor during this step or your measurements will be off.

Finding the Formula
The next step is to enter the data into a spreadsheet program as shown below. We used LibreOffice, which is open source and free, feel free to use Excel, if you own the program and like it better.

A portion of the data we gathered while calibrating our current sensor

A portion of the data we gathered while calibrating our current sensor

Now create a Scatter chart from your data. If you don’t know how to do this, search Google for the instructions; it’s only a couple of mouse clicks. Right click on the data points in the chart (make sure they’re all selected; not just one) and select “Insert Trend Line…” on the drop down menu. A dialog box like the one below will pop up, and under “Type” you should select “Linear” (the exact process might be a bit different for different programs). You should also check the boxes next to “Show equation” and “Show coefficient of determination (R2)”. The R2 value is a statistical measurement of how close an approximation comes to matching the data its approximating. For our purposes, the closer it is to 1, the better the trend line fits the data.

Trend Line Dialog Box

After clicking “OK”, your chart should look something like the one below but without the axis labels (added for clarity). As you can see, our trend line has an R2 value of 0.998, which tells us that the output of the sensor is definitely linearly proportional to the current, and by extension, power.

A graph showing the relationship between voltage and power draw for our current sensor

A graph showing the relationship between voltage and power draw for our current sensor

As cool as the chart is, what you’re really after is that formula, which describes how to take an input voltage and translate it into a measurement of power.

Creating the Arduino Sketch
Now that you have your equation, it’s time to put it to use. Luckily, there’s an example sketch called ReadAnalogValue (it’s under File -> Examples -> 01.Basics) that requires only minor modifications to work for the Current Sensor. The original sketch is as follows:

  Reads an analog input on pin 0, converts it to voltage, and prints the result to the serial monitor.
  Attach the center pin of a potentiometer to pin A0, and the outside pins to +5V and ground.

 This example code is in the public domain.

// the setup routine runs once when you press reset:
void setup() {
  // initialize serial communication at 9600 bits per second:

// the loop routine runs over and over again forever:
void loop() {
  // read the input on analog pin 0:
  int sensorValue = analogRead(A0);
  // Convert the analog reading (which goes from 0 - 1023) to a voltage (0 - 5V):
  float voltage = sensorValue * (5.0 / 1023.0);
  // print out the value you read:

All we need to do now is enter the formula that will convert the voltage variable into a power variable!

  Reads a Modern Device Current Sensor on pin 0, converts it to voltage, calculates
    the power, and prints the result to the serial monitor.
  Attach the V_OUT pin of the Current Sensor to pin A0, and V_IN and GND to +5V and ground respectively.

 This example code is in the public domain.

// the setup routine runs once when you press reset:
void setup() {
  // initialize serial communication at 9600 bits per second:

// the loop routine runs over and over again forever:
void loop() {
  // read the input on analog pin 0:
  int sensorValue = analogRead(A0);
  // Convert the analog reading (which goes from 0 - 1023) to a voltage (0 - 5V):
  float voltage = sensorValue * (5.0 / 1023.0);
  //HERE'S THE ONE LINE OF CODE WE ADDED - your numbers will vary from ours!
  float power = 326.348 * voltage + 26.461
  // print out the value you calculated:
  Serial.println(power); //Don't forget to change the variable name to "power"!

Remember to change the variable name in that last line, otherwise your beautiful formula won’t actually report anything.

Congratulations! Your Current Sensor is now calibrated to measure power draw!

One last thing: now that your calibration is complete and seems to work for the power draws that you expect to see, you might want to lock the sensor to the cord with a spot of hot glue to keep it from rotating and changing your calibration.

Saturation Warning
If you wrote down the saturation voltage when you were testing, you may wish to add code to warn the user if the sensor is saturated (hit its maximum output), so the power draw is probably not proportional to the output voltage any more. Due to the topology of the sensor’s schematic, the sensor’s saturation point (max output) will be about a .6 volts (“a diode drop”) below the supply voltage. If you are using a 5 volt supply, inserting the line below should do the trick.

float voltage = sensorValue * (5.0 / 1023.0); // this line in the code above
if (voltage > 4.30) Serial.println("SATURATED");

The sensor is in the shop here:
Happy sensing and let us know if there is anything in the tutorial that needs to be clarified.

By Jeffrey Blum on May 2, 2014.

Modern Device’s Shipping Policy

In an effort to ensure that customers are completely satisfied with their shopping experience here at Modern Device, we’ve done a little data analysis to come up with our official shipping policy, lovingly titled the 2-Day Guarantee. Basically, if you place an order with us by 3:00 PM, we guarantee that it will ship in two business days or less (some exceptions do apply). If we can’t ship it in two business days, we’ll upgrade the shipping on your order for FREE. For all the wonderful details, read on.

Our Goal: Same- or Next-Day Service

At Modern Device, we strive to fulfill orders as soon as possible, and in the past eight months over half of all orders have shipped the day they were received. More than 80% of all orders have shipped within one business day. Those numbers might be impressive, but we’re constantly working to get them higher. In the meantime, our data shows that a whopping 89% of orders go out within two business days, which is why we’re introducing our 2-Day Guarantee.

Exceptions (The Fine Print)

The 2-Day Guarantee does not apply to orders containing items that have been specifically labeled as pre-ordered or backordered.

Since we are a small outfit, we may not be able to fulfill some larger orders within 2 business days due to production lead time. If you place an order that we anticipate will require more than 2 business days to fulfill, the 2-Day Guarantee will be waived and we will contact you by email with a more realistic estimate of when the order will ship. These estimates are not backed by any kind of guarantee.

Based on the usual USPS and UPS pickup times, we’ve set 3:00 PM as our same-day cutoff. That means orders placed after 3:00 PM count as being received the following business day for the purposes of our 2-Day Guarantee. However, if you place an order with expedited shipping after 3:00 and need it shipped that day, you can call us at (401) 709-2424 and we’ll let you know if we can get it done.

By Jeffrey Blum on April 22, 2014.



One would think that 10 years on, the market for DIY Arduino boards would be somewhat lacking in excitement – to put it in milder terms than I realize a lot of techies might use. Still, TechShop, a San Francisco-based DIY technology and maker space outfit, has been building a lot of our BBB’s (Bare Bones Boards) in their Arduino classes. They find that students are very excited about building their own boards, and then using them to learn how to program.



I have the same experience with the BBB in my classes at the Rhode Island School of Design. But both TechShop and I have had the same experience which is that someone always wants to use a shield of some form, on their board. This creates a form factor problem and while it’s usually fairly easy to solve the problem, the solutions are always sub-optimal, in regards to the form factor. Here’s a BBB sitting on top of an Adafruit Wave Shield, and the “pin torture” that made it happen.

It should be pointed out here, that this whole mess is caused by the Arudino’s failure to mate with a breadboard. This debate goes back to the early days of Arduino and at one point, the Arduino guys were ready to change the form factor to be breadboard compatible, from what they admitted was just a mistake in the first prototype. All seemed good to rectify the mistake when two shield vendors (who shall remain nameless here) complained that their shields would have to be respun or adapted. The rest has been history.  I was part of that online debate so I can say I was there when the Arduino adopted this dubious (or sub-optimal) layout.

In any case, we are many years down that road, and many Bare Bones Boards later. It was time to try again with the existing facts on the ground, to create a breadboard friendly Arduino that still could accommodate a shield. When TechShop asked me to try to reinvent this wheel, I realized that I could also solve the same issue that existed with my own classes.

Here’s the Educato on a breadboard, showing again, what I believe is the advantage of “hiking” the board out over the edge of a breadboard, so that you can use both sides of the breadboard in a circuit. An LED and a resistor, say.


The board looks large but it is really only larger than the UNO outline in two places. In the front row of pins it has two extra rows to accommodate the breadboard pins. On the top right (closest to you in this picture) there is a little tab added on to accommodate the power rail pins. Other than that it’s just a copy of an Arduino Uno footprint. One mounting hole did have to be omitted though to accommodate the analog block. I won’t go over all the boards features here, but let me just mention one.

When we hook up hobby servos in my classes, students inevitably hook them up with their power lines drawing power from the boards power rails. That is, after the voltage regulator.  The stock voltage regulator on the BBB only supports 300 mA so this usually results in sub optimal results and unhappy students. I have to show students how to route the power for servos around the voltage regulator, which has two benefits:

  1. The current available for the motors isn’t throttled down by the voltage regulator
  2. The motor noise and voltage drops from the hobby servos are kept off the main power lines.

The Educato board can be configured to route the power line around the voltage regulator to three power pins on the analog block. These setup was designed to support hobby servos without a lot of fuss. A little shunt just below the analog block headers can be shifted from 5 volts (after to the regulator) to Vin (before the regulator, from the external power jack). This is an ideal power setup for three servos.

The kits come with all the surface mount parts soldered on and tested. It’s an easy build which beginners might expect to take a bit over an hour and more experienced builders a little over a half hour.

To celebrate the Educato launch I am giving away six Educato kits (one to a customer please) with an order over ten dollars. Just use code Educato.


By Paul Badger on April 18, 2014.