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Topic: Leonardo Clone out already! (Read 26070 times) previous topic - next topic

CrossRoads

Well, I am a shield developer too, was never mentioned to me. Maybe I need to get my name on some list somewhere.

Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

picdude777

I have yet to get the bootloader to work with WinXP SP2.

The HID and VCP devices appear to install fine, but AVRDude reports a "avrdude: ser_send(): write error: sorry no info avail" error when trying to upload a sketch.

Both Win7 32 and Mac OS 10.5 work fine with exactly the same hardware and bootloader(s).

This is both with an Adafruit 32U4 breakout and a custom board, using the RC1 and RC2 bootloaders (no difference as far as I could tell...)


Ideas?

westfw

Quote
SCD/SDL

Don't forget that UNO v3, and probably Leonardo as well, has added a couple of extra shield pins for IOC...

CrossRoads

UnoV3 only adds SCL/SDA pins In Parallel with the existing SCL/SDA pins from A5/A4 pins.
Guess as a nod to backwards compatibility.

One would hope that Leonardo makes the 6 extra IO pins available.
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

jwatte


I have yet to get the bootloader to work with WinXP SP2.



For what it's worth: Windows XP SP2 is *no longer supported* by Microsoft. You need to be at SP3, and even that is soon going the way of the dodo bird.

Why does this matter? Because there are no security patches for bugs in XPSP2, it means that any computer connceted to the internet running Windows XP SP2 or below is vulnerable to remote attacks. And this doesn't just affect you -- once your machine is compromised and part of a botnet of some sort, your machine will be used to attack other machines around the world, usually entirely without your knowledge.

Please practice safe hex, and use only supported operating system versions with latest operating system patches, so as to reduce the menace of zero-day attacks and botnet password crackers and DDOS attacks. And please don't encourage others to be unsafe by supporting deprecated operating system versions!


fm

We have just received the boards today! They look fantastic. We have just ordered a few for the vinciDuino team as beta testers but if they go alright, we will be making some more. You can also find all the information about the project: https://bitbucket.org/fmalpartida/vinciduino/wiki/Home released under CC SA-BY.

I will keep you posted about any updates.
   

picdude777

Putting aside the tin-foil hat comments below about XP/SP2, which is probably still installed on -millions- of educational and personal systems, RC2 with the drivers and XP/SP3 does appear to work fine.

Not sure what the bug is, but if it is still an issue with SP2 and release 1.0 it should be addressed if possible.  It's simply not an option to ignore a massive installed base, regardless what the Microsoft propaganda machine reports about Win 7 adoption, nor is berating those who have their baseline default installs of XP on their Dells, HP's, etc.  That accomplishes nothing...


Here's hopin' it gets fixed.




I have yet to get the bootloader to work with WinXP SP2.



For what it's worth: Windows XP SP2 is *no longer supported* by Microsoft. You need to be at SP3, and even that is soon going the way of the dodo bird.

Why does this matter? Because there are no security patches for bugs in XPSP2, it means that any computer connceted to the internet running Windows XP SP2 or below is vulnerable to remote attacks. And this doesn't just affect you -- once your machine is compromised and part of a botnet of some sort, your machine will be used to attack other machines around the world, usually entirely without your knowledge.

Please practice safe hex, and use only supported operating system versions with latest operating system patches, so as to reduce the menace of zero-day attacks and botnet password crackers and DDOS attacks. And please don't encourage others to be unsafe by supporting deprecated operating system versions!



fm

#52
Dec 05, 2011, 06:47 pm Last Edit: Dec 05, 2011, 06:48 pm by fm Reason: 1
Hi chaps,

thought I would share some progress on the vinciDuino. The board is up and running beautifully:
- UART working
- USB working
- I2C operational
- ISP
- digital IO, well I've only tested D13.
- all supplies are good (external unregulated, USB, and UART).

Ripple supply voltage on AVR Vcc pins is less that 5mVpp, a bit better on the analog supply.

I've tried to measure emissions but, silent as a rock with the equipment I have. I can see the cell network, the 50Hz electricity network, but nothing radiated on the 16MHz and harmonics.
   

jwatte


Putting aside the tin-foil hat comments below about XP/SP2


If the installer says "hey, you're running SP2; you need to install the free upgrade to SP3" and exits, that would do the world a net favor AFAIAC.

That being said, I think Leonardo (and the general move to USB) is awesome! Go team! :-)

CrossRoads

Nice work FM.
Do you notice the 5v regulator getting hot at all?
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

fm

Hi CrossRoads, thanks for your comments much appreciated.

I was doing the thermal tests over night, they come out as having a 25ºC case temperature raise over ambient when powered over a 12V power supply and consuming 150mA. In the design, I have limited the current that the linear regulator can supply with the PTC to 200mA, so in theory this temperature rise should be in the range of 35ºC.

We need to re-spin the board to simplify things for people that are starting with SMD soldering, adding a bigger thermal dissipation area to the PCB was on my TODO list and shouldn't bebe a problem.

What are your thoughts regarding D-PAK vs SOT223?

The modifications I did for Rev B, were to change the pads on the SOT223 package (increase the tab and add a thermal pad on the bottom layer to dissipate more heat through the PCB connected with vias).

I suppose that the D-PAK will be about 2 times better as the package thermal resistance is about 2:1 with respect to the SOT223.

What are your thoughts?
   

CrossRoads

Find a part that has the tab as gnd, the thermal pad can be as much as you can spare around it.
Can connect top & bottom of board with vias (name them the same as the pad so they don't get isolated).

For example
http://www.infineon.com/dgdl/IFX25001_DS_101.pdf?folderId=db3a30431ff988150120802bce1d257a&fileId=db3a304320d39d590120f620f1e269da

while
http://www.onsemi.com/pub_link/Collateral/MC33269-D.PDF
needs isolated thermal area, but offers more current.
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

fm

Hi CrossRoads,

thanks for the information, while I did a LD1117 SOT-223 footprint, it ended up not being very practical as I had to move things up and down a bit. I ended up putting the part with thermal pads like the ones in the images below.

The attached images are 3D renderings of what the LD1117 will look like in Rev B of the vinciDuino. You can see that I have added a top thermal Vcc pad, that will also be connected to the +5V pin and also they are connected to the bottom layer using vias.

Even though the 25ºC case temperature raise over ambient is OK, it will not be sufficient to dissipate all the heat at maximum specs, i.e. 1.5W dissipation. I may go for a DPAK instead.

How does it look? Thoughts?
   

roypogi

FM,

I would go with a Dpak with a grounded tab like crossroads suggested, it would eliminate creating a large V+ thermal pad when you already have ground pours. Here are some part numbers that you could use for this. Please check spec sheets for details. They are a little bit more expensive than the V+ tab versions.

LD29150DT50R
TA48M05F(T6L1,SNQ)
KF50BDT-TR
MC7805BDT  - this is non-LDO type
Panucatt Devices

fm

Hi roypogi, thank you very much for your comments. When we selected the regulator, we were looking more to hit a BOM price of 10€ (including PCB), that is why we selected the LD1117.

I was now wandering if we shouldn't have chosen the classic UA78xx. It is a nice all round regulator but has a dropout of about 2V. Having said this, the main use case here is to power the board using a wall transformer and they normally come in 9V and 12V. So it should really be an issue.

@Crossroads - I see that your first choice was the MC33269-D which as the heat tab to Vout. On the board you designed, did you use a specific pour on the top and bottom layer for heat dissipation?

@roypogi - I don't see a good reason not to use a Vcc thermal pad when you have a ground plane. I mean they are both separated and noise shouldn't be an issue here at all. It would be equivalent to having a large pad.

Folks in the Spanish forum are already beta testing the boards and one has already replaced the UNO in a racer robot.

What do you chaps think?
   

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