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31  Products / Arduino Due / Re: Anyone using CMSIS? How to get started? on: April 21, 2014, 03:47:23 pm
These days there's almost never a need for ASM, most (probably all) of the hardware is available to a C program and the code that does this will normally boil down to a single ASM instruction anyway.

There is sometimes a reason to delve into ASM if you really have to control the exact order of instructions etc, but it's been years since I've even thought about doing that, even with fast comms programming.

The last time I used ASM was for a monitor program that displayed all the CPU registers, program counter, stack pointer etc. and these days I doubt many people need a "monitor" program or indeed even know what one is smiley

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Rob
32  Using Arduino / Networking, Protocols, and Devices / Re: Protocol fails on: April 20, 2014, 06:07:24 pm
Why are you printing all those "0x" and ";" ?

Anyway the problem is that the Arduino print functions have no provision to print leading zeros. Have a look at using the sprintf() function, that will allow you to create a formatted string in an array and then you can print the array.

Do you need to display with the 0s? Because if not it's still valid for program use, just move on to the real purpose of your program.

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Rob
33  Using Arduino / Programming Questions / Re: Adjusting simple (so it should be) shift register coding for a different result on: April 20, 2014, 04:18:51 am
So do you want the LEDs to go like this as you rotate the knob from 0 to full.

Code:
********  // fast anti-CW
-*******
--******
---*****
----****
-----***
------**
-------*
--------  // stop
-------*
------**
-----***
----****
---*****
--******
-*******
******** // fast CW

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Rob
 
34  Using Arduino / Networking, Protocols, and Devices / Re: what is the best protocol to connect more than 512 devices to an arduino?? on: April 19, 2014, 11:00:35 pm
I think you will have trouble using any bus with 500+ loads hanging off it.

How fast do you need to update the nodes?

Can you split them into a few groups?

What about daisy-chaining as that has no practical limit to the number of nodes (or the distance between them depending on the speed required).

Does it have to be a single motor per node? Can you say have 4 to reduce the number of nodes to 128?


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Rob
35  Using Arduino / Programming Questions / Re: How do I move a sequence through an array? on: April 19, 2014, 10:52:03 pm
Quote
I strongly support the method suggested by @DavidOConnor in Reply #1.
+1

There's almost never a good reason to physically move bytes around in C.

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Rob
36  Community / Gigs and Collaborations / Re: Project - Will pay for completion on: April 19, 2014, 10:46:55 pm
Does it have to be a real book? If not you can place all the mechanism inside a fake one and push/pull against a fixture at the back of the book shelf. That will not require any access to the rear, drilling of holes etc and will be 100% hidden.

Of course if the object is to allow you to then remove and use the book that's a different story.

This is why people need to know everything about a project.

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Rob
37  Using Arduino / Programming Questions / Re: Understanding Interrupts on: April 19, 2014, 10:35:35 pm
You can use them wherever you like. No need to include anything, they are part of the core.

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Rob
38  Using Arduino / General Electronics / Re: blackout circuit - 300ma cc circuit on: April 19, 2014, 10:16:43 pm
Firstly, what are you talking about.

Secondly, all that and you still have 145uA "leakage" current? Wouldn't a low-side FET be easier and better as well?

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Rob
39  Using Arduino / Project Guidance / Re: Automatic plant watering system on: April 19, 2014, 10:04:51 pm
Something like this I would think

http://www.ebay.com.au/itm/Ultra-quiet-Mini-DC-12V-3M-240L-H-Brushless-Motor-Submersible-Water-Pump-New-/231021868292?pt=LH_DefaultDomain_15&hash=item35c9f9f504

It's 12v though, any reason you can't use 12v?

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Rob
40  Using Arduino / Project Guidance / Re: Automatic plant watering system on: April 19, 2014, 06:48:29 pm
Quote
Would a pump like this fit the bill?
That pump looks like it's designed to be mounted directly onto a tank, much like the car windscreen washers we talked about before. In most situations that would not be appropriate as it's a lot easier to connect a pump with proper in/outlets.

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Rob
41  Using Arduino / Project Guidance / Re: Senior Project Multi-Processor Arduino Board on: April 19, 2014, 06:31:05 pm
Yeah I remember talking about doing that.

Using FIFOs or DPRAM would just be a fun thing to play with, total overkill for a dual AVR board though, a bit like having the Nürburgring or Daytona to yourself and doing laps in a Prius.

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Rob
42  Using Arduino / Project Guidance / Re: Senior Project Multi-Processor Arduino Board on: April 19, 2014, 07:42:19 am
Quote
Multiple processors should only be introduced if there is a need to do more than one thing at the same time, not just to improve speed.
Yes that's true, especially given the range of fast CPUs these days, multi-CPUs is a pet hobby horse of mine and even I struggle to justify it and for simple speed increase I can't at all.

In areas like offloading time-consuming IO (like the Lynxmotion SSC-32 Servo Controller) or maybe handling a complex serial protocol (technically the W5100 or FT232 are co-processors) I think there's a place for them.

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Rob
43  Products / Arduino Due / Re: Bill Of Materials (BOM) required for Arduino DUE on: April 19, 2014, 03:16:48 am
Arduinos are open source right? So is there not an official BOM and correct schematic available?

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Rob
44  Using Arduino / Project Guidance / Re: Senior Project Multi-Processor Arduino Board on: April 19, 2014, 03:10:15 am
For two CPUs some FIFOs  or dual-ported RAM would be fun to play with.

I'm currently working on a system that can have a master and 15 co-processors, loosely coupled with either SPI, UART or I2C.

Don't ask my why you would need 15, it just seemed like a nice round number smiley

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Rob
45  Products / Arduino Due / Re: Small-footprint Due on: April 19, 2014, 02:55:17 am
You want to be careful about feature creep, I've done two Due-compatible designs now and in both cases they got too big and complicated so I ditched them.

OTOH it's a shame not to have all the SAM features smiley

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Rob
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