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1  Development / Other Hardware Development / Re: Does FTDI232 chip need programming before use? on: September 29, 2014, 05:27:08 am
It works out of the box, you probably have to load a driver (I can't remember now) but that's all. And follow the current hardware designs of which there are 1000s.

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Rob
2  Development / Other Hardware Development / Re: I2C port expanders PCF8575C vs. MCP23017 on: September 28, 2014, 06:00:59 pm
The 23017 etc are very common and I'm sure there are libraries to drive them, not sure that is the case with the 8575.

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Rob
3  Community / Bar Sport / Re: Altium will soon be free on: September 28, 2014, 05:52:03 pm
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Every hour I spend learning a new CAD software is an hour that I can do other stuff...
Ain't that the truth. Even if you have a free version of a CAD package it's a major investment in time to get up to speed with it and you would need a very good reason to change.

As you probably know I'm not a fan of Eagle but it obviously does the job and it's better to get stuff done than be always learning new software.

If this free/cheap Altium works out I will certainly be recommending it to people who have not already invested in something else (ie beginners), but those who have can decide for themselves if it's worth swapping, I doubt it would be.

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Rob
4  Using Arduino / Project Guidance / Re: Pin Outputs In Parallel/Disabling Pins? on: September 28, 2014, 09:54:28 am
If two pins of opposite voltage levels get connected you will likely blow the circuitry behind the pins and maybe other stuff in the chip as well.

The diodes need a current-limiting resistor right? How about you use two, one on each Arduino pin, that way if your code stuffs up you are only sinking 1/2 the LED current through each pin as the current path is through the two resistors.


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Rob
5  Community / Bar Sport / Re: Altium will soon be free on: September 28, 2014, 08:21:48 am
I think the business model is still open to being changed, I can't see them claiming your designs, if that were the case not a single person would sign up.

But yes you would have to read the fine print that's for sure.

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Rob
6  Development / Other Software Development / Re: pcb design schematic on: September 28, 2014, 07:33:54 am
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the question is on the first page..
Yeah sorry, I didn't see that I'd landed on page 2 smiley

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Rob
7  Using Arduino / Project Guidance / Re: Detect the position of a modelrailroad turnout on: September 28, 2014, 03:20:44 am
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Or am I overthinking this?

Probably smiley

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Rob
8  Using Arduino / Project Guidance / Re: Figuring out how to use a DC motor to rotate a solar cell towards the sun on: September 27, 2014, 08:39:23 pm
Also there's no need to have the cells in each corner, you can put them together with an X-shaped vane between them. That has been done a 1000, the above-mentioned Google search should find examples.

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Rob
9  Using Arduino / Project Guidance / Re: Pin Outputs In Parallel/Disabling Pins? on: September 27, 2014, 08:36:36 pm
Yes you can, but you have to be very careful to make sure both Arduinos are not driving at the same time, so you will need some mechanism for each to tell the other that it wants control.

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Rob
10  Using Arduino / Microcontrollers / Re: LPC810 mini ARM Prozessor in 8 pin dip package on: September 27, 2014, 06:12:38 pm
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Most (maybe all?) of the NXP ARM chips have a bootloader in ROM which runs an ASCII protocol over UART, so the great thing is you don't need any programming hardware apart from a USB-TTL adapter.
Yes, silly me, I forgot about the ROM-based bootloaders. I think you can even do drag-n-drop onto the chip if you use the USB mass storage option. That's something I need to investigate although I admit I've never been a great fan of drag-n-drop because it requires mouse movements, but maybe that can be automated as a simple copy.

I was very keen on the LPC11U68 but now I think I'm in love, I've been reading up on the LPC1549 and what a great chip that seems to be. Not as many serial ports as the U68 but an M3 and a lot of other nice features.

The SWM (pin switch matrix) is fantastic, it allows most functions to be MUXed to most pins, and I almost wet myself when I found that there's a Tx idle interrupt on the USARTs smiley

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Rob
11  Using Arduino / General Electronics / Re: PCB Manufacture on: September 27, 2014, 07:43:09 am
Yes you should be able to place any text or graphic you like on the "silkscreen" layers, I don't know how you do that with Fritzing though.

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Rob
12  Community / Bar Sport / Altium will soon be free on: September 26, 2014, 02:07:19 pm
Yes that's right folks, the Holy grail of PCB design is almost upon us. Altium are developing a free version called CircuitMaker

http://circuitmaker.com

But before you wet yourself be advised that (at present) it is cloud storage only. Yes, no local storage. For many people (myself included) that's a deal breaker but to be fair Altium are listening to the great unwashed and this may change. I hope so.

If you have a week to spare you can read more about it here (40 pages and growing daily)

http://www.eevblog.com/forum/altium/free-altium-is-coming/

Note the vitriol about cloud storage. But as I said the features are still being decided so watch that space. At this point it seems that you can use the totally free version and "rent" upgrades, so for example if 100x100mm is the limit for the free version (I say "if") but you have a one-off requirement for a 100x200 you can rent that functionality for as long as required to do that job. Same for other features like say 6 layers etc.

IF the prices are reasonable I think this is a good model.

A free/cheap Altium has been the impossible dream for as long as I can remember, once you Eagle guys try it you'll never go back smiley

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Rob
13  Development / Other Software Development / Re: pcb design schematic on: September 26, 2014, 01:45:23 pm
And the question is...

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Rob
14  Using Arduino / Programming Questions / Re: Storing Code on an I2C EEPROM on: September 26, 2014, 01:43:46 pm
You would have to write a custom bootloader that does not trash the main body of the code, just grabs the function and places it at a known location. Having done that it would also have to have some way of determining what needs to be done so you can still load the main code. Maybe have a GPIO pin that's tested on entry to the bootloader.

Also is it possible to get GCC to generate code at a given address? Or is the code position independent anyway?


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Rob
15  Using Arduino / Programming Questions / Re: error message "void not being ignored as it should be" on: September 26, 2014, 01:38:18 pm
digitalWrite() is a void function, you cannot assign it's return value to anything as there isn't one.

Code:
;j<38, k < 5;

Is that even valid code?  It compiles but I don't know what it does.

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Rob
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