Depron Airboat Worklog #1

One of my first DIY RC projects was a Depron Airboat I've build almost exactly 2 years ago. 12x6x2 inch hull, motor, servo, rudder and ESC. And honestly, I loved it. It was a great fun playing with it. Too bad, it did not survived very long. It broke in a middle of a lake and I decided my live is worth more. All I have left is a video

This season I started to build another Depron airboat. Slightly bigger, heavier and with more power. And partially 3D printed. Hull will be made from Depron, but propulsion and steering system will be (is) printable.

Depron RC Airboat Propulsion system

After few hours of printing time, propulsion and steering is done. What is left is to make a hull. 18x8x2 inches made from 6mm Depron. I might cover bottom with glass fiber and impregnate with polyurethane wood glue diluted with alcohol.

New thing will be a reversible ESC. I've already configured and tested FVT Littlebee 20A to act as reversible ESC and it seem to be working like expected. I only wonder how effective rudder will be when on reverse. Not much I effective probably…

Depron RC Airboat 3D printed Propulsion system

And yes, STL files will be available when this is proven to be working. Everything for the community 🙂

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GPS Racer: worklog #4

Yesterday I finally maidened my GPS Racer in full FPV configuration. RunCam Owl Plus and VTX finally arrived, it was not raining, so I took recording gear after sunset and went flying.

To be precise, it was not "night". But it was pretty dark. Too dark for my RunCam Swift. Owl Plus was sensitive enough to fly. It was not perfect, but doable. Next step: not IR blocked lens and IR emitter for real night flying. Both have been ordered.

Plus, thanks to GPS and OSD I finally saw the speed this thing can do. 92km/h recorded, but that was not the limit on those 6030 props. I do not think I've opened throttle to max…

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3D Printed Paddleboat

3D Printed Paddle Wheel Boat

It's not a secret, that me, and QuadMeUp, are not only about quadcopters. From time to time I like to do something completely different.

When I was a child (10-12 or something like that) I loved to build boats. Simple crude design: styrofoam or bark, simple sail or DC motor and tinwire propeller. No RC link. Just let it sail in "somewhere there".

When I got a 3D printer and learned that servos can be converted to continuous rotation simply by replacing potentiometer with a pair of resistors, the idea to build paddle wheel boat powered by servos was almost obvious.

So, here it is!

3d printed paddle wheel boat

  • Hull can be 3D printed, STL files are available on Thingiverse
  • Wheels are powered by 2 TowerPro 9g servos converted to continuous rotation
  • RC link by cheapest FrSky compatible D8 receiver
  • 2S LiPo gives enough "juice" and with power usage of about 300mA it can sail for hours

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GPS Racer: worklog #2

I'm once again realizing, that doing multiple things at once is not a way to work. Something like that happened to my GPS Racer project. According do original plans, week ago I was only supposed to wait for FPV camera.

Instead of that, only yesterday I finished ESC and motor assembly. But OK, it was a little trickier than I expected originally:

  1. Since I wanted to reuse onboard current meter of Airbot Omnibus F4 (v2) Pro and use Matek XT60 PDB at the same time, I had to do some creative wiring between XT60 plug and PDB. Instead of directly connecting XT60 plug to PDB, + first goes to current meter on Omnibus F4 Pro and then goes back to PDB. Not pretty, but works. I still have to design some kind for power plug holder, but this topic can wait. I still have no FPV camera
  2. I had some problems with ESCs. Not only I've destroyed Motor1 soldering pad, but failed to flash FVT Littlebee 30A with latest BLHelli. Bootloader survived, but BLHeli was gone. I have to connect ESC to other FC and then reflash. I wonder if it was hardware or software issue…
    Right now, apart from FPV gear, FrSky receiver, GPS mount, SmartPort inverter and final assembly GPS Racer is few steps closer to being finished. With upcoming Easter, it should be functional in April. Can't wait…

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Project “GPS Racer” – worklog #1

I know that I should not start new project when old one are still in progress. I really, really know that. But since I’ve somehow lost my interest in Project Dualcopter and I have a real need for a new quadcopter, Project “GPS Racer” has finally started.

What is GPS Racer? During my work as INAV developer, I’ve realized that I do not have a good platform for it. The only GPS enabled multirotor I own is Sparrow Hawk. And it has a gimbal, weight 2kg and is hard to transport. When Sparrow Hawk crashes, there is always something broken.

So, to be able to test navigation related features of INAV, and not have to rebuild every single crash, I’ve decided to build dedicated UAV. For most elements I will be using parts that I already have. I only had to order frame, propellers and GPS module. Continue reading “Project “GPS Racer” – worklog #1” »

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ESP8266 and DS18B20 – wireless ThingSpeak sensor

Here is another small project of mine: battery operated ESP8266 ESP-01 WiFi thermometer using DS18B20 and ThingSpeak API to collect data.

Before we proceed, you should:

esp8266 ds18b20 thingspeak sensor

Continue reading “ESP8266 and DS18B20 – wireless ThingSpeak sensor” »

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Project Dualcopter – worklog #2

3 weeks after my first post on Project Dualcopter, it's time for small update. The plan was to install servos and control surfaces. Instead, I've done:

  • Basic electrical wiring for motors and ESCs. They have power now and are ready to be connected to flight controller
  • To level shelf (above propellers) designed to hold flight controller and radio receiver
  • Think for a moment about landing gear. Yeap, there will be some sort of shock absorbers
  • Think for a moment where battery will be placed: as low as possible to keep center of gravity below center of thrust
  • Decide which propeller should run clockwise and which should run counterclockwise: top should go clockwise, bottom should go counterclockwise

dualcopter esc soldering

dualcopter esc

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ATtiny85 Light Sensor – I2C slave device

I love AVR ATtinyx5 series microcontrollers. They are cheap, easy to use, they can be programmed just like Arduinos and comparing to their size they offer great features. For example, they can be used as remote analog to digital converters connected to master device using I2C bus.

Background: few year ago I've build a weather station based on Raspberry Pi. It collects various data and displays them on dedicated web page and Android app. Every few months I try to add a new sensor to it. Last time it was a daylight sensor. Raspberry Pi does not offer ADC inputs and I has few ATtiny85 on hand that time. One to another, few hours later: photoresistor based daylight meter sensor connected via I2C bus.

ATtiny85 as light sensor with I2C bus

Electric assembly is pretty simple: ATtiny85 directly connected to Raspberry Pi via I2C, photoresistor with 10kOhm pull down connected to ATtiny85 and signal LED.

attiny85 i2c slave light sensor with photoresistor

Code driving this rig is also pretty simple: watchdog timer wakes up ATtiny every few minutes, measures voltage, filters it and stores in memory. Every time read operation is requested, last filtered ADC value (10 bits as 2 bytes).

I2C support is provided by TinyWireS library that configures USI as I2C slave.

/**
 * This function is executed when there is a request to read sensor
 * To get data, 2 reads of 8 bits are required
 * First requests send 8 older bits of 16bit unsigned int
 * Second request send 8 lower bytes
 * Measurement is executed when request for first batch of data is requested
 */
void requestEvent()
{  
  TinyWireS.send(i2c_regs[reg_position]);

  reg_position++;
  if (reg_position >= reg_size)
  {
      reg_position = 0;
  }
}

/*
 * Setup I2C
 */
TinyWireS.begin(I2C_SLAVE_ADDRESS);
TinyWireS.onRequest(requestEvent); //Set I2C read event handler

Example code to read from device might look like this:

Wire.requestFrom(0x13, 2);    // request 2 bytes from slave device #0x13

int i =0;
unsigned int readout = 0;

while (Wire.available()) { // slave may send less than requested
byte c = Wire.read(); // receive a byte as character

if (i == 0) {
    readout = c;
} else {
    readout = readout << 8;
    readout = readout + c;
}

i++;
}

Serial.print(readout);

Full source code is available on GitHub and my Weather Station with almost a year of light level history is available here.

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Project Dualcopter – worklog #1

Flying season 2016 is slowly coming to an end on northern hemisphere. That means less time spent on an airfield and more time spent behind a desk. For this autumn I've found a very interesting, small project: Dualcopter.

Dualcopter is an UAV with two coaxial contra-rotating propellers and 2 control surfaces driven by servos. Lift and yaw are controlled by propellers, while pitch and roll by ailerons placed below motors. This video illustrates how it looks like:

My Dualcopter will be slightly different. Instead of foam and wood I will use 3D printed parts connected together CA glue and zip ties. Maybe it will not be super strong and probably will not survive any crash, but should be enough to make it fly for a minute or so. Almost all parts would be either 3D printed or taken from spare box. I'm not planning any new purchases.

Planned specs:

  • Motors: Turnigy MT2213 935KV
  • Props: APC 1045 MR
  • ESC: Afro 20A
  • FC: Flip32 probably with INAV inside
  • Battery: 1300mAh 3S
  • Weight: around 800g with battery

dualcopter 1

So far, after 2 evenings I have this:

dualcopter 2

Two motors mounted on a frame.

Next step would be to build bottom section with ailerons and battery compartment.

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