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16  Forum 2005-2010 (read only) / Troubleshooting / MCP2515 CAN Controller on: October 14, 2010, 12:07:14 pm
I've successfully set up an Arduino UNO and Microchip MCP2515 CAN Controller and I'm down to one last little issue.  I can reliably read messages generated by a Microchip test board, but when I send incremental test messages once a second the test board seems to drop the occasional message.  I don't get any transmission errors from my MCP2515, so I'm wondering if this is just a problem with the receiving board/software from Microchip?  I would have though it more likely to be something wrong with what I've done, but with no errors being generated I'm at a loss.

Just wondering if anyone else has had similar issues?  I'm not going to worry about it too much because my project is hardly mission critical, but it's always nice to know what's going on.

As an overview to my setup:

Hardware:
  • UNO, MCP2515/MCP2551, 16MHz ceramic resenator.
  • Resenator limits my set up to 125kHz transfer.
  • MCP2515DM demo board from Microchip set at its minimum rate of 125kHz.
  • Using INT pin on MCP2515 to notify of full RX buffer, empty TX buffer and Errors.
Software:
  • Checks INT and reads from RX buffer if full.
  • Prints outgoing message to Serial on each successful TX interrupt, (buffer goes to empty - supposedly successful transmission), and never misses a beat.
  • Uses millis() not delay() to time TX messages.
  • During this normal operation never get an Error interrupt.
  • Can force errors by trying a non-matching transfer speed, so I know the Interrupt works.
17  Forum 2005-2010 (read only) / Troubleshooting / Re: A Wee Problem on: October 08, 2008, 04:41:26 pm
Well I'm only working with really small sketches at the moment, so I doubt it takes more than a few seconds to upload them.  It seems noticeably slower than the Sanguino I was using, but nothing that concerned me.
18  Forum 2005-2010 (read only) / Troubleshooting / Re: A Wee Problem on: October 05, 2008, 03:42:26 pm
With my Pro Mini I was getting errors, (can't remember if they're the same as yours or not), and the most successful way for me to upload sketches was to hold the reset button in, start the upload and immediately release the button, (within a second or two of starting the upload).

Might be worth a try.
19  Forum 2005-2010 (read only) / Development / Re: Attempting surface mount parts - how to solder? on: October 19, 2010, 12:53:54 pm
I'm pretty much a newbie when it comes to soldering, but I successfully soldered a similar connector for the 408 on to the Sparkfun GPS shield using a soldering iron with a fine tip.  (Not ultra fine, just smaller than I'm used to.)

I spread on a little flux and soldered one mechanical mount first.  Since everything was still lined up I did the other mount and then touched each of the connections.

It was the first tiny part I'd done, and it worked so I'm happy!  (Not to say I did a great job, but it does work. smiley-grin)
20  Forum 2005-2010 (read only) / Interfacing / Re: Connecting Arduino to iPhone/iPod serial on: April 05, 2009, 12:34:35 pm
I don't know how much iPhone/Arduino stuff has been mentioned here, but from what I understand OS 3.0 will allow access to the serial connections through the SDK.  I downloaded it last night to try out, but I need to get myself a Touch for development and install OS 3.0 Beta.  Hopefully by the end of the week I'll be able to have some working code.

If anyone's interested send me a PM with ideas.  When I get started I'll open up another thread.
21  Forum 2005-2010 (read only) / Interfacing / Re: use an ipod touch 'to control' the arduino on: April 05, 2009, 12:52:54 pm
Quote
I know I'd like to have my Touch and Arduino talking without jailbreaking.
I'm working on this.  It'll be on OS 3.0 though.  I've downloaded the SDK, but I've decided to get myself a Touch that I can install OS 3.0 Beta on instead of borrowing my wife's. smiley-grin

When I get started I'll start a new thread.  Maybe the end of this week or the beginning of next if I can get some working code.
22  Forum 2005-2010 (read only) / Interfacing / Re: XBee and bluetooth on: November 11, 2010, 04:17:01 pm
Paul, I think you may be misunderstanding him.  It looks like he's trying to connect his Bluetooth enabled Arduino to his Bluetooth enabled laptop.  The equipment he has should be able to do it, but I have no experience with Bluetooth so I can't help beyond that.

I'd contact Seedstudio to make sure that you've got them connected properly and that you're issuing the commands correctly.

ETA:  OK, having re-read his posts I'm not sure what Bluetooth device he's connecting to, beyond trying to communicate with the Arduino over USB.  Should still work though.

ETA Again!  I really should read more carefully.  What's X-CTU?  :-[  Maybe this is what the problem is.  If this is specifically used to configure XBee, then i doubt it would work.  However, the shield just gives access to the device, so you should be able to configure it with the appropriate commands.  Again - ask Seedstudio.
23  Forum 2005-2010 (read only) / Interfacing / Re: Returning an output pin to floating state. on: November 19, 2008, 10:34:50 pm
Thanks guys!
24  Forum 2005-2010 (read only) / Interfacing / Re: Returning an output pin to floating state. on: November 19, 2008, 10:14:06 pm
Thanks! I was just wondering if that was the answer. smiley  But what's hi-Z?
25  Forum 2005-2010 (read only) / Interfacing / Returning an output pin to floating state. on: November 19, 2008, 10:00:41 pm
I've hooked my Arduino up to a Lantronix MatchPort which has a reset pin.  This pin is normally left floating and taken to ground when a reset is required.  If I hook the reset to an Arduino pin I could set pinMode to output, take it high, and then take it low when I want to reset.  However, this means that it will normally always be high.  I don't know if this is a problem or not, but it seems a waste, (of something, I'm just not sure of what!).  What I'd like to do however is simply return it to a floating state, i.e. as it is before you set pinMode.  Is this possible?  Worth it?  Am I crazy? smiley-grin
26  Forum 2005-2010 (read only) / Interfacing / Re: Battery Charging and Gas Gauge on: December 06, 2010, 10:40:32 pm
There are a lot of battery fuel gauge chips out there that will do what you want for the cell chemistry of your choosing.  Dig around these sites under power management:

www.maxim-ic.com
www.microchip.com
www.ti.com

Put in the parameters you want, (V, Ah, chemistry, etc.) and you'll probably find a single chip solution that has I2C or similar interface.  You'll probably want to look for an easily solderable package, but there are some out there.

And look through this forum some more.  Just in the last day or two someone posted bout a shield they'd made.  I'll see if I can find it.

ETA:  Here's that link: LiPoly Fuel Gauge
27  Forum 2005-2010 (read only) / Interfacing / Re: Serial LCD Help on: November 26, 2010, 12:02:18 am
At the risk of making a fool of myself, but I think you need to connect the Arduino pin marked RX to the SerialLCD RX pin.  Looking at the schematic of the UNO it appears this pin is connected to the TX pin of the ATmega.  This is for the Arduino UNO, don't know if it applies to anyother variations, and I can't confirm that this is 100% accurate information as I haven't used the TX/RX pins successfully yet.  It's just what I see when I look at the schematic.

On the silkscreen for the UNO there's a little arrow by the TX and RX pins.  I think this arrow is supposed to indicate direction of data flow, if I'm correct.  If I'm not then I'm sure there's plenty of people out there to correct me. smiley-grin
28  Forum 2005-2010 (read only) / Interfacing / Re: Arduino + GPS Shield on: October 19, 2010, 07:11:44 pm
Quote
If you have dddmm.mmmmm split into ddd and mm.mmm, then convert mm.mmm to .dddd if needed.
Isn't that what the pseudo-code does?  And of course if you don't like it, don't use it.  smiley-wink

So a challenge for you.  Come up with something better. smiley
29  Forum 2005-2010 (read only) / Interfacing / Re: Arduino + GPS Shield on: October 19, 2010, 03:51:17 pm
Yup. Same principle. NEMA dddmm.mmmm

74 degrees
10.5833 minutes

07410.5833 / 100 = 74.105833

x = 74, y = 0.105833

longitude = 74 + 0.105833 * 10 / 6 = 74.17639

30  Forum 2005-2010 (read only) / Interfacing / Re: Arduino + GPS Shield on: October 19, 2010, 03:10:49 pm
Because y in this example is minutes/100, not minutes.  So I could do y*100/60, or y*1.66666, or y/0.6 it's all the same.  (y*10/6 is not the same as y/60 though).

However, the important part to get the NEMA value in to decimal degrees is to break out the degrees and add to it the minutes divided by 60.  I was trying to show it pseudo-programatically and there may be a more fancy/simple way of doing it.
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