DIY-Multiwii Flight control board for 1K

[sooraj.palakkad]

Atmega328+MPU6050+FTDI232RL  With Multiwii F/W

          There are a wide range of multicopter flight controllers available nowadays, from as cheap as 1K to High ends which cost up to 10k.  However beginners like me who are just getting in to the rc hobby may find it little difficult to invest on Items like flight controllers, Radio systems Etc..(the later burns holes in the pocket!!!). As a beginner I searched for the cheapest components through the internet. How ever i couldn't compromise on quality and usability. Things like Radio, and Flight controller are not that easy to get cheap. (Those are cheap, are found to be worth the money!! I mean worth what we payed!!!.)

           So I came to the choice of making my own flight controller, And these are the Immediate problems struck me.

• Which micro controller
• Which sensor
  
• which firmware or program
• Is it worth DIYing?

            I have found solutions for these by going through RC forums and blogs And came to these conclusions.

• Arduino as micro controller platform
• any cheap ACC. GYRO. combo chips (like MPU6050)
• Miltiwii , as it has support for all the features of an elite Flight controller  
• This is cheaper than Buying a FCboard and is worth investing, as its features can be extended

            Still i found one more problem, the arduino board costs around 25$(cheap Chinese clones are available for 7$!), If i go on using an arduino uno, there is no worth DIYing as the total cost is concerned. The other choice is to use an Atmega328 with arduino boot loader, this costs only 2$ and I will have a complete DIY FC board So I chose to Go on with it.

            Now I a have ordered my parts From Ebay and waiting for these to arrive,

         

• Atmega328P with arduino boot loader $1.5
• MPU 6050 breakout board                $4
• PL 2303 USB to TTL RS232               $1.5  (cheaper than FT232RL)
• HC-05 Bluetooth wireless serial         $5    (This is optional, for connecting FCB wirelessely to PC)
• Logic Level converter                      $1
• 16MHz crystal, 2x22pF ceramic capacitors, LM7805 etc...(These items are found in the junk box of any electronics hobbyist however costs only up to 30Rs.)

             So far total Budget is around 1K, !! For a Wireless connectivity dual sensor (Accelerometer and Gyro) Flight control Board!!!!!!!!!.   The Bluetooth module is optional, So with out that , cost reduces to around 700Rs.

             The future mods I have planned are , MPU9150(has built in compass) instead of MPU6050+Barometric pressure sensor+GPS module, And Atmega2560 instead of  Atmega328P  . Guess what? That would have Features of APM !! , For a too low price.

             Currently I am waiting for my parts to Arrive (And my 5th sem exams to end!!) Will Update with Build details Once I get my parts, Keep your Fingers crossed for a Cheap, Yet Highly powerful DIY Flight controller                              

[shijin ps]

Wish you all the best dear friend.

[sooraj.palakkad]

@ Shijin, 

[sndipz]

All the best !!

[sooraj.palakkad]

Thanks , Sandipz.

[akhilzid]

I think you can jump to second stage directly because the costs matters.

and i already done this with atmega2560 , gy80 , ublox neo 6m , 3dr telemetry and multiwii had great success.

[sooraj.palakkad]

Cost difference in moving to second step, Atmega2560 will cost 5$ and MPU9150+BMP085+GPS will cost around 30$, Nothing else to change . Currently Designing the PCB , in 50mm x 50mm.

[sooraj.palakkad]

@akhilzid , gy80? the Chinese breakout board?, I had no faith on it!!. In fact I am not Planning to use break outboards, 'm designing my own PCB

[akhilzid]

pin layout and pcb design will not much differ while MPU9150 and gy80 breakout,

gy80 is chinese but flying more than one year with that. and also tried have MPU6050 make any diffrence.

[AnjanBabu]

MPU 6050 breakout (GY-521, I think)-- 200/-
Arduino Pro Mini (16MHz/5V)-- 160/-
5x5 perf-board-- 15/-
A few headers and a couple of jumpers, of course. ~10/-

>500/- in cost.

I didn't go as far as flying with it, I am always paranoid of fly-aways so just did some tethered hovering to check stability, the 6050 breakout was affected by the vibrations a bit, but it wasn't bad at all for an evening's work.

[AnjanBabu]

Atmega2560 will cost 5$

$5 excluding shipping or free shipping?

[sooraj.palakkad]

pin layout and pcb design will not much differ while MPU9150 and gy80 breakout,

gy80 is chinese but flying more than one year with that. and also tried have MPU6050 make any diffrence.

Akhil, MPU6050 and 9150 are Single chip Motion sensors, gy80 is a breakout board with separate 3axis aa. +3axis gyro +baro +compass. As i am making a custom PCB decided to go with MPU9150+BMP085 everything in two chips !

[sooraj.palakkad]

MPU 6050 breakout (GY-521, I think)-- 200/-
Arduino Pro Mini (16MHz/5V)-- 160/-
5x5 perf-board-- 15/-
A few headers and a couple of jumpers, of course. ~10/-

>500/- in cost.

I didn't go as far as flying with it, I am always paranoid of fly-aways so just did some tethered hovering to check stability, the 6050 breakout was affected by the vibrations a bit, but it wasn't bad at all for an evening's work.

Gr8, Why not flying with it? It's as reliable (or more than that) as KK or HK fCboards.

[sooraj.palakkad]

Atmega2560 will cost 5$

$5 excluding shipping or free shipping?

That's from ebay, ofcourse it's freeshipping. (But it is the IC only not Arduino Mega)

[AnjanBabu]

As i am making a custom PCB decided to go with MPU9150+BMP085 everything in two chips !

MultiWii does not support the 9150/9250 as of yet, you need to mod the compass code. I think the MWC boards mostly come with HMC5883L 3-axis compass.

[sooraj.palakkad]

MPU 9150 is Simply, The MPU6050 +magnetometer AK8975 .
The Implementation is quite simple...
Just define MPU6050 and define AK8975 in multiwii code, it should work. The sensor orientation may need to be to be modified.

[AnjanBabu]

The MPU's DMP is used to processing sensor data on MWC before it goes to the microcontroller, so I'm guessing the compass data also goes though the DMP, in that case it can't be as straight forward as you mention. Also, the compass I2C address might need a check.

[sooraj.palakkad]

i found that it is Directly working, On multiwii forum, however will give it a try As MPU9150 is cheap!!

[sachin_k5]

Hi sooraj , which software will you use to simulate the circuit ?

[sooraj.palakkad]

There is no need to simulate the circuit, As multiwii is a tested and trusted program by so many RC enthusiasts around the world.
For designning the PCB I will be using DIPTRACE.

[sooraj.palakkad]

after about a month wait, I finally got the sensor breakout boards , USB to UART TTL converter and Logic Level Converter delivered. Now waiting for my 5th sem Exams to end 

[sooraj.palakkad]

another sleepless night, brought an arduino UNO from a friend Bootloaded my new Atmega 328P. Actually, on the Ebay listing , it was said it comes preloaded with optiboot bootloader, but mine was not so when arrived- But no problem, I don't mind whether it's bootloaded or not, for a 60Rs. IC (local electronic shops sell it for 180Rs here !).
           uploaded multiwii firmware to it and connected mpu6050, to check if the multiwii GUI detects it- Success- So everything is still on the breadboard, time to bake a new PCB.
                But now I am confused whether to solder the sensor and bluetooth breakout boards directly or De solder the breakout board and use the IC's only , the latter makes the size of final Flight control board smaller, and will give the feel of an Of the shelf board.      Any suggestions?

[Dharmik]

Really nice job. Looks interesting. Keep it up.

[sooraj.palakkad]

@Dharmik, thanks.

[sooraj.palakkad]

Was trying my luck with some KK5.5 and hobbyking v2 boards, for set it up and learn some flying skills with the multirotor.

Now I gave up, as these boards are giving new problems after solving one another 

So Today I decided to set up this multywii FCB on a perf board (general purpose dotted PCB) . I was not at all interested to do this, Was planning to make this FCB after getting my SMD PCB design etched. but have no time to etch a PCB right now.. And I wanna fly.

So it happened today..... took an old 328P , a gy-521 breakout (MPU6050), and started soldering...
though it is not a clean build , It should work.
So I call this Mymultiwii V 1.0 

and guess what, I maintained the size of FCB to be less than 50*50mm even in a perfboard with all DIP components and a sensor break outboard  !!!

But couldn't test it today, because my USB to UART (PL2102) breakout is not functioning 

Will do the testing and hopefully flying with this 'not so clean' board with in two days.