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16  Using Arduino / Programming Questions / Re: A better way to do my bit reordering? on: August 17, 2014, 12:23:10 am
Quote
PCB is made already.
Then shoot the designer (It wasn't you was it smiley), that is unforgivable unless there is a good reason that's not obvious.

I tried to think of  a clever way to do this but that mapping is so bad I don't think there is a good way short of a 65k lookup table.

You could reduce the loop by 4 iterations as the lower 4 bits are correct.

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Rob
17  Community / Bar Sport / Re: connectors on SMD modules [follow up: do elecrow, itead or seed do half vias?] on: August 17, 2014, 12:04:58 am
I'm assuming that four layers is the new two layers, in other words nobody does two layers any more (do they?).

Also assuming that there is only a single signal going to the via (kind of a given I suppose smiley).

Then technically there is only a need for a single pad as there is only a single signal, however by having pads on every layer the via is a lot stronger mechanically and unlikely to be torn off by the router when the board is cut to shape



The arrows point to three pads that do nothing electrically but a lot mechanically.

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Rob
18  General Category / General Discussion / Re: Arduino for industrial automation on: August 16, 2014, 07:50:00 am
That's a well-designed system at first glance.

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Rob
19  Using Arduino / Programming Questions / Re: SPI.transfer() on 74HC595 - problem on: August 15, 2014, 09:22:01 am
OK I gotta ask, why are you doing it this way?

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Rob
20  Using Arduino / Programming Questions / Re: SPI.transfer() on 74HC595 - problem on: August 15, 2014, 09:18:36 am
That SR is only for outputs. Try a '165.

EDIT: Oh I see you are pulling some sort of flanker by feeding the outputs back to an input. I'll have to study that.

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Rob
21  Community / Bar Sport / Re: connectors on SMD modules [follow up: do elecrow, itead or seed do half vias?] on: August 14, 2014, 10:29:33 pm
They are called castellated vias.

One thing you should do is connect them to internal layers with pads, this helps save them from being ripped off by the router.

I've done a design with them but it never got produced.

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Rob
22  Community / Gigs and Collaborations / Re: Arduino Prototype Developer Hard/Soft Wanted ! on: August 14, 2014, 10:24:30 pm
I got this as an email, see here

http://forum.arduino.cc/index.php?topic=260923.0

As presented this is not a serious RFQ, there is no way to quote using this information and Fritzing, give me a break.

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Rob
23  Community / Gigs and Collaborations / Re: Warning: BS RFQ on: August 14, 2014, 09:05:23 am
I tried to post without it turning into a link but even without tags it still does it.

Anyway I don't think there's anything wrong with the site as such.

EDIT: There, I added spaces to stop that.

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Rob
24  Community / Gigs and Collaborations / Warning: BS RFQ on: August 14, 2014, 06:44:09 am
I just got this email

Quote
Dear

We are looking for a Arduino developer (Freelanc) to work on a protoype project. The project needs to have thermal sensor, RF 433 (or Zigbee, zwave for example in order to use grid power), and will be low power, small size, and low cost, based for example on pro mini arduino.


In order to have more detail,  non-disclosure agreement will be required before you start.

The ideal candidate would also have experience designing circuits around Arduino or other microcontrollers, including programming of accessory circuits transmitting data via RF.

Deliverables will include a number of system components including
1) PCB designs 2) prototypes 3) software to control, send/receive data 4)fritzing file


Send us your resume and projects you have developed with Arduino. In your application please propose an estimated timeline, hardware costs, and labor.

Best regards

Note that they are asking for a quote for time and materials before even saying what the job is. Also they (I assume) expect a professional designer but then say you have to supply Fritzing files. WTF?

I was about to respond with a rude letter when I noticed there was a DOCX file as an attachment. (Nobody should open a DOC file unless you really know it's provenance)

The embedded links all point to www. selfadvert. com

This has to be a virus or at least spam. But at least I guess that means Arduino has really arrived smiley

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Rob
25  Using Arduino / Programming Questions / Re: SPI - Slave Send A String To Master Example on: August 08, 2014, 06:32:48 am
I don't know why you have to "restart" the SPI, if you send 10 bytes you will get 10 bytes in return (assuming the slave code is written correctly).

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Rob
26  Using Arduino / Programming Questions / Re: Splitting a String into two other Strings on: August 05, 2014, 04:50:31 am
The strings look like all the information is at fixed locations, so all you need to do is use a couple of pointers. Here's a small test prog that I think does the job.

Code:
void setup() {
 
char test_str [] = "SRC: [8M4GQQ-1] DATA: !0304.57NI10135.55E#9 243565";
char * Callsign = test_str + 6;  // point to [
char * Data= test_str + 22;    // point to !
test_str[14] = '\0';   // overwrite ] with NULL to terminate callsign part of string and therefore create a new string

Serial.begin (115200);
Serial.println (Callsign);
Serial.println (Data);
}

void loop() {
 
 
}




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Rob
27  Using Arduino / Networking, Protocols, and Devices / Re: Wiring multiple devices to Arduino through SPI on: August 01, 2014, 09:47:26 pm
Yes you need to organise your own wiring, either with a breadboard or whatever method is easiest.

And yes, working with embedded processors is more "dangerous" in that you can easily blow up something. That said chips are usually pretty robust and you have to do something really stupid or be unlucky to do real damage.

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Rob
28  Using Arduino / Programming Questions / Re: Memory Test on: August 01, 2014, 09:41:22 pm
@Placido, the chances of you having dodgy RAM are almost non-existent, whereas the chances of you running out of RAM are extremely high, in fact that's one of the most common problems we see around here.

You do not need a RAM test function, you need to look at re factoring your code to use less RAM.

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Rob
29  Using Arduino / Project Guidance / Re: How to detect length of circuit? on: July 31, 2014, 05:24:07 pm
As is often the case we need further information but the OP has disappeared.

If it's the normal random stack of blocks I think this will be very difficult, something like what KeithRB is proposing I guess but the logistics of powering all the CPUs and making reliable connections will be a drama.

But until we know more I'm out.

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Rob
30  Using Arduino / Programming Questions / Re: Cyclic Redundancy Check(CRC) code in arduino on: July 31, 2014, 12:01:45 am
If the values are same then there is probably no error.

I don't know if you can get a BER from a single check on the entire file though.

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Rob
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