Melih Karakelle's Posts (46)

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3689687992?profile=original"Google/Nest’s decision raises an interesting question. When software and hardware are intertwined, does a warranty mean you stop supporting the hardware or does it mean that the manufacturer can intentionally disable it without consequence? Tony Fadell seems to believe the latter. Tony believes he has the right to reach into your home and pull the plug on your Nest products.

On May 15th, my house will stop working. My landscape lighting will stop turning on and off, my security lights will stop reacting to motion, and my home made vacation burglar deterrent will stop working. This is a conscious intentional decision by Google/Nest.

To be clear, they are not simply ceasing to support the product, rather they are advising customers that on May 15th a container of hummus will actually be infinitely more useful than the Revolv hub.

Google is intentionally bricking hardware that I own. They don’t even dance around it, here is Revolv’s FAQ."
(the image above)

Please read full story here:

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3689680781?profile=originalHi Everyone,

After 5 months of design and test process, new DroneThermal v022016 thermal camera boards are ready to announce. 
This is probably the smallest analog (PAL/NTSC) thermal camera in the world. 

Dimensions : 20mm x 20mm x 15mm (included Lepton 25 degrees core)
Weight: 3 grams
Resolution: 80x60 pixel.

I'm building a new FPV microquad and a rover for videos. I hope weather will be better in following days for outdoor videos. 
3689680958?profile=originalYou can follow the process and updates from our Instagram account

For more info, please visit the Product Page

hank you for reading.

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image_27.jpeg?189db0Hi Everyone

Last weekend I've tested Panasonic NCR18650B batteries on my maiden PolyClub EPP airplane. 
I was expecting ~40 minutes flight but I landed after 103 minutes 24 seconds! (1h43m24s)

This batteries are definitely working!
Only disadvantage of the batteries are low discharge rate. It is max. 2C.
So, discharge current should be less than 7A for 3400mA NCR18650B

You can find other photos and details in my blog:


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FLIR Lepton vs Apple Facetime HD Camera

Hi Everyone,
Yesterday, I shot this video with my MacBook Air and DroneThermal camera.

The results are promising. Thermal image resolution is only 80x60 pixel but sensitivity is not bad.

BTW, We designed an optional 3D printed (SLS) case for the camera. It looks better :) has some difficulties in these days. We will share the 3D print files soon on our web site and Shapeways.


Thanks for reading

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25° Thermal Camera Cores for Drones

3689642424?profile=originalHi Everyone,
Good news for small drones, New FLIR Lepton 25° camera cores just arrived. 

If you have read this post before , I have tested our new camera design with 50° version of Lepton and the range was shorter than 50 meters for human body because of wide angle lens design and low resolution of Lepton. 

So we ordered 25° FOV FLIR Lepton modules to DroneThermal cameras instead of 50°.

These new cores are  fully compatible with current developer boards and other Lepton based designs.
3689642389?profile=originalI tested it and zoom factor is exactly 2 times higher than the previous one.(test video coming)

DroneThermal analog thermal cameras will come with these new cores. We are waiting for PCB manufacturing now then I will share final product details and features.

You can find more details and photos under the product page.

Thank you for reading.

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Hi Everyone,

I'm happy to present the final prototype of DroneThermal micro size analog (PAL/NTSC) thermal camera. 
The project started 3 months ago and we have published some samples on 

our facebook page on 1 March 2015.

After hundreds hours of code work and design changes, the final prototype is ready for production. We signed the agreements with FLIR for Lepton thermal camera cores as well. 

3689641341?profile=original DroneThermal is based on FLIR's low cost 80x60 pixel Lepton camera cores.
Video frame rate and resolution is not much but the price is perfect for civilian small drone hobbyists.
You can pre-order it now, in order to take the advantage of %15 Spring discount.

3689641446?profile=originalComposite video signal resolution is higher than Lepton, so we can resize the thermal image and add some extra information into the video output. ( marking hottest and coolest objects etc. )
Unfortunately radiometry(temperature reading)  looks nearly impossible because of high math and affects of air temperature, thickness, pressure, reflection rate of the objects and camera body temperature. 

I'm working on some cool features , so please share your opinions with me for improvements.


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Hi Everyone,

I'm working on Bluetooth Low Energy (BLE, Bluetooth Smart or Bluetooth 4.0)  technology since summer 2013 and after few hundred hours code work my first BLE product(iCELL) ready to show and I'm happy to share here with the community.

May be you know, Some Android devices and all iPhones(since 4S) including this low power transceivers.
I think BLE will be most important interaction method for near devices at the future. Currently you can find thousands different BLE device on the market and hundred thousands coming. 

iCELL hardware is a small electronic hardware with 8 cell battery reading capability and you can easily connect it to balance port of your LiPO to read battery voltage and cell conditions from your iPhone or iPad. (details here)

BLE has some limitations. The range around 30-100 meters. Data speed ~200 byte per seconds max. Not useful for drone data telemetry but possible to make your multirotor settings before flight or checking some important variables when your platform passes above you.
Main advantage is iPhone/iPad/Android. Everyone has one of them. Software update is easy. Screen is tough sensitive. Resolving all display problems on a single platform. 
The second big advantage is "Low Energy". BLE devices can works 1 year with a coin cell.

Now I'm working on a weather station for house usage, a camera trigger for timelapse, a camera slider and lost plane beacon. All of them working over BLE.  

Please share your opinion about iCELL idea. is it useful? or useless? 
and If you have any new idea for BLE technology please feel free. I will glad to work over it. 


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How About Open Source?


Yesterday HK released a video about their new 433Mhz LRS modules.
And i shocked. Because it is unauthorized copy of my OpenLRS !

OpenLRS is an Opensource RC and i'm the developer of that system.

Stop the video on 1:08 and check the receiver.
And check the pinout or something.

Only the difference is 6 pin ICSP. We don't need that because of our production procedure.

Now the question is "What can i do?"
If i cant find an answer about that, i will stop to designing open source hardware.

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OpenBee Telemetry Traffic Test

Hi everyone, 

Another blog post about OpenBee :)

Everyone asking about telemetry speed but i didnt answer this questions because of nature of RF telemetry.
RF telemetry speed depends more than one thing. I just take this video for showing unidirectional communication limits. 
The limit depends FSK modulation frequency and RF bandwidth. We can increase the limit but range reduces.

As you can see on the video, OpenBee handling %47.7 of 115200 baud without any problem. I guess 5500 bytes per seconds (55.000bps) is enough for most of telemetry project :)

I'm using firmware v1.01 on this video, we can add MAVLINK packers and other useful codes. 

Please feel free for any question and request. 



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UHF Spectrum Analyzer with OpenBee

Hi Guys,

OpenBee modules ready and in stocks today. I just tested Dennis Frie's spectrum analyzer firmware and software over OpenBee. It is working perfect!. The original code a part of OpenLRS RC Receivers and OpenBee using same RF module and pinouts with OpenLRS project, this is why the code working without any problem. :)

In this video, I'm using 1W UHF radio on 459.075Mhz, and analyzer scanning 455-465Mhz band.

You can download the codes (Telemetry and Spectrum Analyzer) and software from OpenBee repository 

And upload into OpenBee easily

Here is the details of Dennis Frie's Spectrum Analyser project:

And OpenBee product page:

Please share your comments with us




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OpenBee Modules Ready!!!

3689481953?profile=originalHi Guys,

Today OpenBee boards arrived from PCB factory and i just tested them and working fine :)

It is including Arduino 16Mhz ProMini bootloader and you can upload the code directly over Arduino with USB to Xbee Adapters. No need an external FTDI board or something.


We are producing OpenBee modules with U.FL socket. PCB also compatible with SMA connectors. 
OpenBee modules will be in stocks in 2-3 days on

Now i'm writing some codes for OpenBee hardware and need your help. If you want to develop something over OpenBee, please contact me. 

Google code page will be ready in few days:


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3689478149?profile=originalHi Guys,

As you know, we are working on OpenLRS project since few years and It is an Open Source RC control system with telemetry, I2C and others. Few days before i designed this new boards. It is based on OpenLRS system but there is no 3.3v regulator, PPM or Servo outputs. It is an open Source Telemetry Module with XBee footprint.   And today prototype boards arrived and i populated it for test and passed. Now we are waiting for quality PCB production (15 days).


  • No more buffering problem of Xbee modules. Real time telemetry or control is possible.(10ms latency)
  • Longer Range, lower frequency
  • No networking stack. Everything in the code. You can write a mesh or point to point, everything is possible.
  • Arduino ProMini based boot and Open Source design
  • No Programmers or FTDI cable require. Just put it to USB to XBee adapter and load the firmware over Arduino. 
  • XBee footprint. (Serial pins only)
  • 100mW 400-470mhz RF Module with FHSS and other functions (RFM22B)
  • up to 3 miles range. (The record is 12KM with Nagoya antenna in England)
  • 3.3v design.


My Job List:

  • Open google code page for OpenBee in a few days (
  • Isolate the OpenLRS code's telemetry part.
  • Test it at the field.
  • Add an option for  MAVLink packages (need help!!!)
  • Find project members.
  • Add the code for simulating OpenLRS Transmitter modules. Computer based RC control is possible with OpenLRS Receivers. Joysticks or something like that.  

What are you thinking about OpenBee project?  Is it good or bad idea? 

Thanks for your comments

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Hi Everyone,

I'm working over some LANC controllers since few months. LANC is the camera control protocol by Sony and most of  Sony, Canon and Panasonic cameras using this protocol to control the camera features by a cable remote. 
I'm designing LANC RF links and other LANC products for video production market.

My new product is a RC LANC controller over servo lines and it is currently in production. 
It is supporting Zoom(In-Out) and Rec(start-stop) functions. 

Please share your idea about this product. It is useful or not? Need extra features? for drones?



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MQ-200 microquad setup and first flight


Hi Everyone,

Maybe you remember, last week my 200mm size quadrocopter (MQ-200) was lifted a GoPro.
After outdoor flight under 15-20km wind conditions without any problem,  i designed MQ-202.
It is same size microquadro but including landing gears and more rigid than MQ-200.

MQ-202 flying with OpenLRS Multi board with MultiWii code. If you interesting, I just released the code in the MultiWii repository .

This weekend i will test Magnetometer and GPS functions(RTH and waypoints). 
I think these small size quads sufficient for some tasks (FPV patrol or taking video with gopro). We will try and learn their limits :)



Last video from my retired MQ-200 :)

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Open Source I2C GPS - Navigatron

Hi Everyone,

If you are developing some GPS based applications maybe you know, GPS data protocol is serial and %90 of data is just garbage. You have to listen it every time, data parsing a headache and impossible to making other time critical applications in same time.

I'm glad to announce the Navigatron - I2C GPS solution :)

Navigatron is an Arduino based board with GPS and backup battery. It is including Atmega328, FTDI port and 16mHz clock and working with 3.3-5v (you must replace the backup battery charge diode with a blue led for 5v applications)

I wrote my own I2C codes and tried other I2C project since 1 years but they wasn't enough easy. Most of I2C GPS codes sending all values in a single stream. Then 2 month before a guy (EOS Bandit) from MultiWii forum find a simple and perfect solution. His code simulating a real I2C device and you can access each register address separately.

Navigatron is coming with EOS Bandit's firmware with MultiWii 2.0 support. It is an opensource and you can replace the firmware for your requirements.

It is also storing/calculating way points and giving the direction and distance for you. This is perfect solution for low speed microprocessor based UAV applications because just you need a magnetic compass value for finding the way to home(or waypoint)

Here is the current I2C register addresses of gps values:


I2C_GPS_STATUS 0x00 //(Read only)
---I2C_GPS_STATUS_WP_REACHED 0x08 //Active waypoint has been reached (not cleared until new waypoint is set)

I2C_GPS_COMMAND 0x01 //(write only)
---I2C_GPS_COMMAND_POSHOLD 0x01 //copy current position to internal target location register
---I2C_GPS_COMMAND_RESUME 0x02 //copy last active WP to internal target location register
---define I2C_GPS_COMMAND_SET_WP 0x04 //copy current position to given WP
---define I2C_GPS_COMMAND_ACTIVATE_WP 0x08 //copy given WP position to internal target location register
---define I2C_GPS_COMMAND_WP 0xF0 //Waypoint number

I2C_GPS_WP_REG 0x06 //Waypoint register (Read only)
---I2C_GPS_WP_REG_ACTIVE 0x0F //Active Waypoint
---define I2C_GPS_WP_REG_PERVIOUS 0xF0 //pervious Waypoint

=== Values ===
I2C_GPS_GROUND_SPEED 0x07 //GPS ground speed in m/s*100 (uint16_t) (Read Only)
I2C_GPS_ALTITUDE 0x09 //GPS altitude in meters (uint16_t) (Read Only)
I2C_GPS_TIME 0x0b //UTC Time from GPS in hhmmss.sss * 100 (uint32_t)(unneccesary precision) (Read Only)
I2C_GPS_DISTANCE 0x0f //Distance between current pos and internal target location register in meters (uint16_t) (Read Only)
I2C_GPS_DIRECTION 0x11 //direction towards interal target location reg from current position (+/- 180 degree) (read Only)
I2C_GPS_LOCATION 0x13 //current position (8 bytes, lat and lon, 1 degree = 10 000 000 (read only)
I2C_GPS_WP0 0x1B //Waypoint 0 used for RTH location (R/W)
I2C_GPS_WP1 0x23
I2C_GPS_WP2 0x2B
I2C_GPS_WP3 0x33
I2C_GPS_WP4 0x3B
I2C_GPS_WP5 0x43
I2C_GPS_WP6 0x4B
I2C_GPS_WP7 0x53
I2C_GPS_WP8 0x5B
I2C_GPS_WP9 0x63
I2C_GPS_WP10 0x6B
I2C_GPS_WP11 0x73
I2C_GPS_WP12 0x7B
I2C_GPS_WP13 0x83
I2C_GPS_WP14 0x8B
I2C_GPS_WP15 0x93
I2C_GPS_WP_NAV_PAR1 0x9B //Waypoint navigation parameter 1
---I2C_GPS_WP_NAV_PAR1_REACH_LIMIT 0x0F //lover 4 bit, waypoint reached distance
I2C_GPS_GROUND_COURSE 0x9C //GPS ground course (uint16_t)

For Schematic/Sample Codes and other details:

Have a nice weekend

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Smallest Quadrocopter with GoPro

Hi Guys,

The title is a little bit ambitious but i guess no one tried to lift a GoPro with a 140gr Micro Quadrocopter before :D

The throttle was %80 when flying with half drained 2S LiPO battery, this is why it is a little bit aggressive.

This is my micro quadro setup

3689448968?profile=originalController:Opensource OpenLRS Multi receiver with Gyro and Acc with onboard radio receiver
Firmware: MultiWii v1.9 (modified for OpenLRS onboard receiver)
Frame: MQ-200 microquad frame
Props: HK 5x3 (black/red) props.
ESCs: FL6A Fast PWM 6A ESC (Hobby King 6A with firware update)
Motors: HK 10gr




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Hi Guys,

My new OpenLRS Rx Multi boards arrived yesterday.
It is most simple quadro system, because controller firmware working into the RC receiver's processor :)
No need to any wiring for sensors or controllers, just plug your ESCs and fly.


Circuit %100 compatible with our other OpenLRS Rx v2 boards and including extra 2 pot, 3 axis Gyro(ITG3205) and 3 axis Accelerometer(ADXL345). I will share the codes and schematics into the product page.

I used modified MultiWii v1.9 on my receiver but you can load other opensource projects that they are using Arduino Atmega328 base. OpenLRS Rx v2 including I2C for sensors, a FTDI port and  PWM pins as servo output.

I'm waiting to spring days for flying outdoor and writing some autopilot codes into the board for stabilizing my planes and RTH functions.

Have a nice weekend


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Hi Everyone,

Maybe you remember, I released OpenLRS Opensource RC radio system in this summer and promised "you can use our receivers as multicopter controller" 

I'm glad to share our new code implementation for MultiWii. 
We added OpenLRS tab into MultiWii 1.9 firmware and replaced 10-15 lines into the original code for radio system integration. Then you dont need an extra controller board just connect your OpenLRS radio receiver and sensors for flying :)

OpenLRS Rx v2 boards supporting all(6) hardware PWM channels of Atmega328P. You can use most of arduino based multicopter controller firmwares with X,+,Y,6Y,Hexa or Octa frames.

As you can see on below, we are using only radio receiver and sensors (ADXL435 + ITG3205 breakouts) for this flight.
ESCs directly connected to OpenLRS receiver. I used our sensor breakout boards, because of stackable board design. We can plug all(acc,gyro, pressure, magnetic) sensors with one 4 pin header in 15x15x8mm space. ITG3200 board under the ADXL345 board in this photo. 

I used unpopulated controller board as base plate, this is why everything looking in red :) 


I used's GrassHopper Basic frame.  Ozan(owner of designed this revolutionary frame for durability and camera mounting without propeller perspective. It's only 3 boom quadrocopter frame, simple like our controller concept :)



Google code page for OpenLRS codes:

OpenLRS product page for hardwares:

Our OpenLRS forum for questions

Thank you for keeping open your codes!  


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Hi Everyone,


Maybe you know, i'm working on Open Source RC (OpenLRS) project since 1-2 years and we released it in this summer.

Today I just finished the firmware v1.10 with transparent serial bridge!

This mean, you can talk with autopilot or other telemetry modules without any extra telemetry device. Your OpenLRS Rx and Tx can handle this mission.


Download link:


OpenLRS Forum link:

Rx to Tx transmission supporting 750 byte/seconds (not bit/second) without any problem. 
It's handling 9600 baud signals with %80 traffic.
But Tx to Rx (ground to air) transmission sharing the servo communication bytes and we are not suggesting more than 100 byte/second for ground to air transmission.

We are suggesting 115.200 baud serial speed (%5 traffic) for clear serial. If you want to use 9600 or near speeds dont forget; Atmega328(with Arduino) can read the signal with hardware without any problem, but it have to wait for next byte when writing. You must finish the writing before reading next RF package. This is why you need high speed communication when writing something on the serial out. 
As a reference: In this video, i'm using 9600 baud on GPS side and 115.200 baud on computer side.




Old Diydrones blog posts about OpenLRS Project



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