Maybe we could set up a paypal for those of us that would like to contribute and offer support for the R&D testing of intia boards and components, similar to the way we could support Alex.

Happy New Year's Fellow MC fly'ers.

Jussi take a well deserved break!

Cheers.

For large production, www.pcbcart.com or www.goldphoenixpcb.biz should be better, as they have better quantity prices, the goldphoenix is great if you design a rectangular/square board as they even score the panel for free.

Hello

If I had one wish, it would be the one to build the Mega Seeeduino a Octocopter. Enough outputs are available. Unfortunately I have not the slightest idea about the program.

Happy new year

Greetings Sven

Hello people. Some time to spare here....

@ Senso, I will add that regulator after all! I agree that it wont add much rto cost....

@ Norbert: I am game for trying something new, but I think seeedstuido is not that much slower if we opt for UPS or DHL shipping! I am laying out the board with 10mil (0.254 mm )tracks so it should fit Olimex specs!

I have had some boards done at Olimex and I was in no way impressed with the quality.....

Happy new year!

Jussi

They started to call me The Guy,
Who builds but doesn't fly
I think this isn't really fair
Just try'n to get it in the air!

https://www.rcgroups.com/forums/show....php?t=1286011

Norbert aka kinderkram @ RCG

Hey Norbert! Hope you didn't damage the quad too much!
Looking forward to your posts in 2011, cool pic!
Matthew

LOL

Yes, multicopters are fragile creatures, hope you did not hurt it too much!

Now that we are into crazy stuff and complete disregrad for own safety.....Is the fireworks season 2010/2011 gonna bring us the first video of a a rocket-launched/assisted multicopter? Warthox - I dare you! That could be the fabled "million hits RC-video!"

In antisipation of the new boards I tried etching my first PCB, actually came out pretty well (Thumb left in for size reference)

Now time for some stove top reflow testing, solder paste is expensive i see!

Happy new year to everyone!!!

Originally Posted by 420RcPilot

There is also a some 0.22 uF, and 2.2 uF on chargepump for ITG3200. And a 4.7 uF tantalum on the HMC5843. What is your opinion on those? (Take a look at updated schematic posted by EBD)

Cap C3 (connected to pin 20 of ITG) is 2.2uF in the schematic but the datasheet specifies 2.2nF

Originally Posted by 420RcPilot

I am counting on you to volunteer your soldering skills in the prototype run

I'm ready. Challenge me

Originally Posted by 420RcPilot

I am kinda new to magnetometers. Are there any special concerns on placement and proximity to other parts? (Besides of course that it of course should be kept away from EM emitters and large metal objects) Am I asking for trouble by mounting it together with the other sensors?

Datasheets says this about caps for HMC5843:

But the example schematic shows C1 as a polarized cap... I chose a B-case tantal for this....but is it that overkill?

I am unfamilar with ESR theory for capacitors. Quist- what is your opinion! Is the 0402 gonna be too small for C2 and 3.3V decoupler on HMC5843?

Make sure you do not have any tracks carrying large currents close to the sensor.
Regarding the caps, I would use 0603 or larger, since you do not have very strict space restrictiong. Instead of the polarized cap you can use ceramic X7R caps.

Originally Posted by 420RcPilot

Arduino ProMini shield has 3.3 regulator - all other 5V duinos have 3.3 supply, so I propose we use that. Looking at datasheets for sensors and taking capacitor charge surge into account I highly doubt we will draw more than the 50 mA limit! But I could be wrong...opinions, please! Quist?

The average current will be below 50mA but the inrush current will be above 50mA, but it is ok because it is designed to handle it.


In general:
I would recommend using X7R ceramic capacitors (especially for C10 & C11).
When you route the traces on the board, try to keep most of the routing on the topside and have the bottom layer as a shielding layer. I know you will need to have tracks running on the bottom layer, but try to avoid slicing the ground plane in small pieces with the tracks.

Happy New Year
Quist

Originally Posted by K Quist

In general:
I would recommend using X7R ceramic capacitors (especially for C10 & C11).
When you route the traces on the board, try to keep most of the routing on the topside and have the bottom layer as a shielding layer. I know you will need to have tracks running on the bottom layer, but try to avoid slicing the ground plane in small pieces with the tracks.

Happy New Year
Quist

Thanks for those pointers. I was actually laying out the board with ground plane on both top and bottom layer. Are you saying I should ditch the top one and run small vias from each GND pad to the bottom layer instead!

I will try and keep most tracks on the top layer - it makes more sense anyway for SMT! I have sized all caps up to 0805 and specified XR7 for all!

Following your recommandations, I added pads for a SC-70/Sot-23 positive 3.3V LDO regulator (Texas Instruments - TPS71733,150mA/2.5V- 6.5V)

I choose this one deliberately because it is cheap, common and manageable to solder! I also do not think an IMU really requires to be fed up to 30V.....so although LT1121 is good it would completely overkill and up to 5 times as expensive depending on supplier!

Originally Posted by 420RcPilot

Thanks for those pointers. I was actually laying out the board with ground plane on both top and bottom layer. Are you saying I should ditch the top one and run small vias from each GND pad to the bottom layer instead!

I will try and keep most tracks on the top layer - it makes more sense anyway for SMT! I have sized all caps up to 0805 and specified XR7 for all!

Following your recommandations, I added pads for a SC-70/Sot-23 positive 3.3V LDO regulator (Texas Instruments - TPS71733,150mA/2.5V- 6.5V)

I choose this one deliberately because it is cheap, common and manageable to solder! I also do not think an IMU really requires to be fed up to 30V.....so although LT1121 is good it would completely overkill and up to 5 times as expensive depending on supplier!

I would say, go with ground plane on both top and bottem and place a via close to the GND pins. You can use the ground plane on the topside to reduce crosstalk between data lines (ex. SDA and SCL), by running the ground plane between the datalines.

Sounds good with the caps.

Yep, components from Linear Technologies are quite expensive, but often they have a cool feature the competitors don't have.

/Quist

Ok - Here goes...

There is probably something I overlooked or got wrong, so I woudl apreciate if someone goes over it with a fine tooth coam.....

Have I died and gone to heaven? I am first in line.

Jussi, nice job!!! Just curious, why did you use vias on the ADXL345 SDA trace instead of routing it around the SJ1 solder jumper? Maybe it's just my personal preference, but I try to minimize the use of vias.

Again, nice job! Can't wait to get my hands on one!

Originally Posted by 420RcPilot

Ok - Here goes...

There is probably something I overlooked or got wrong, so I woudl apreciate if someone goes over it with a fine tooth coam.....

Wow, Jussi! You must have spent New Year's day in front of your computer, I guess.

Frankt T. posted another "FreeIMU" 9DOF in the MultiWii thread:



Maybe this could be helpful for comparison?