Arduino Nano Flight Controller

Keeping Joop Brooking’s “Let’s keep it simple” theme intact, this design further simplifies Brooking’s YMFC-AL hardware while the firmware remains the same. The biggest change is that the Arduino UNO is replaced with Arduino nano. This design declutters the mesh of wires required in the UNO version as well as provides the RC receiver space on top of MPU6050.

Hardware:

The simple thing about this design is that it can be hand soldered, no circuit layout necessary and only handful of parts are required.

Parts Required:

1. Arduino nano
2. MPU 6050
3. Resistors: 1.5k, 1k, 330
4. Diodes: 1N4001, LED red
5. black female headers: 21
6. male headers: 6
7. multicoloured wires
8. soldering rod and soldering wire

Following are the steps needed to make a Flight controller shown in ascending order:

      

An Arduino nano is attached to the board using the female header pins. Note the missing pin under the A6 of nano. It is removed, as A6 is unused in this design, to make the routing the ground to the MPU 6050 shorter as shown below in figure 8. Below right is the MPU 6050 sensor with pins attached. Also, note the pins on MPU6050 are soldered in an unusual way as can be seen in figure 7.

      

The sensor MPU6050 is attached to the board using double-sided foam tape to reduce the vibration induced interference. The SDA and SCL pins of the sensors are bridge soldered to the A4 and A5 pins of the Arduino nano respectively.

Four colored wires are used to connect the signals (roll, pitch, throttle, and yaw) from the Radio Control receiver to the A8, A9, A10 and A11 pins of the Arduino nano.

The 7 by 3 black female headers are used to latch the receiver, shown in the background, just above the sensor and the wires. Note the white double-sided foam tape seen below the sensor.

 

            

The back side of the PCB shows the signal output to the 4 ESC. Below that are the four points where the colored wires are attached. The long trace at the top-center is the ground path whereas below that path is the 5v trace linking 5v from Arduino to the receiver.

   

And finally, the LED, battery voltage level detection resistors, diode and power input pins are soldered.

Software: 

As for the software portion, it can be downloaded from here. It is one of the simplest code for a quadrotor control and is very well documented with how-to-videos and instruction on troubleshooting with intricate details made by Joop Brookings himself. You can also find his Youtube channel here.

Zero Watt Turbine

It’s been two years since my last blog post. This blog post is about a hydro-electric turbine that produces electricity but does not require electricity during the making process and hence its name: Zero Watt Turbine.

Image by Nathan Eagle and Benjamin Olding

Zero watt Turbine started with a small and simple idea/question: What if people at off-grid locations, especially in developing countries, could make their own renewable energy generators to power their houses or at least generate basic electricity to light their houses? I had observed that people in hilly regions of Nepal have been using Ghattas (traditional water mills)to harness renewable hydropower for centuries to grind grains to make flour. So, it was possible that they could be generating electricity too. After some googling around I found that some of the Ghattas in Nepal have been modified to generate electricity at night and charge batteries while during the day they were used to mill the grains.

Inspired from electrified Ghatta, I started to make a small portable turbine which could be made by anyone having basic artisan skills. But I soon faced a problem that I had not anticipated. I had to wait weeks before I could fabricate my parts at a local workshop as it was at the peak of load-shedding (power-cuts) season in the winter and the workshop had a huge backlog.

That made me completely rethink the way I was going to design the turbine.  The design constraint that I set for myself was that it had to be made without using any power tools that required electricity. This was important because people in rural off-grid locations usually don’t have access to machinery or the electricity to operate them. Even for lighting, they rely on kerosene oil lamps and small portable lights.

After several design iterations, I came up with a design that satisfies the constraint and one that could be made using 100% off the shelf parts. One can make it with bare hands albeit some hand tools like a riveting machine and hand drill has to be used. Here are some of the design iterations of the rotor/blades:

            A turbine rotor made using blades out of CPVC pipe and a base plate out of                         75mm PVC cap. It was laborious to drill and cut those pipe pieces.  Aligning the               two holes was also a problem.

             A turbine rotor made out of a wooden octagon and the inner surface of the holes              function as blade surface upon which the water hit.

            Another wooden rotor prototype with two layers of plywood cut in a certain                       geometry which makes blades when stacked together.

            Improved 110mm PVC cap rotor design using Aluminium C-channel cut as blades            and attached to the rotor using rivets. This design led to significant improvement               in the output voltage.

             Final rotor design using 110mm PVC cap and aluminum window lock bits as                        blades which were  riveted onto the rotor head.

           The flipped rotor head clearly shows the rivets attached.

Some of the pictures of the working prototype at the test site near Bhardev village, which is located 20km south of Kathmandu, are shown below:

                  

The site where the turbine was installed and me performing some necessary tweaking.

 

                                                  Some plumbing

  In comes water, out goes electricity: a working prototype.

Tap water diverted to the turbine.

Voltmeter indicating some voltage is indeed being produced using this turbine for the first time.
                                             And finally, some light to pierce the darkness.

This blog shows how the idea evolved from a simple inquiry to a working prototype. On the next blog, I’ll be posting about how to make it, the technical specifications, improvements made on the turbine and the possible ways to scale it.

 

My new electronics work bench

With the making of a new electronics work bench i am starting this new blog. I had been doing mechanical and electronic fabrication on a single bench and it was kind of messy. Now every thing is in order, and neat and tidy. Now that there is a work bench, i am starting to imagine all kinds of things that could be made possible with it. What shall i make first?