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46  Development / Other Software Development / Re: How to change rs-232 port mode to half-duplex? on: September 06, 2014, 06:56:59 pm
Good point.

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Rob
47  Using Arduino / Microcontrollers / Re: Uploading code to multiple micro-controllers simultaniously on: September 06, 2014, 05:47:15 pm
As has been noted you need a network running first, no matter what the final programming solution is. That could be I2C, RS485 etc etc. Anything that allows multi-drop. But assuming that's in place and also assuming we are talking about reflashing the chips (because just sending new parms over I2C is hardly worth talking about smiley)

Each node has a serial Flash/EEPROM/MRAM/FRAM/SRAM (let's call it EEPROM for now), part of the normal running code checks the network for a "burn me" command, having got that it reads a HEX file from the network and stores that file in EEPROM, any one or all of the nodes can do this at the same time with an appropriate protocol in place although for error reporting it might be better to do one at a time, makes no difference to the operator as there will be a program written on the PC to handle this all as a single operation.

When the nodes have successfully received and stored the new code they set a flag in the EEPROM and jump to the bootloader.

The bootloader checks that flag and reflashes the chip or not according to it's state. After flashing it clears the flag.

Another option would be to use a chip that allows code execution from RAM, I think that all ARMs can do that, in this case your "bootloader" is the main flashed code, it does similar to above then jumps into the new code in RAM. That code has to also sniff the network for the "burn me" command or maybe you have a hardware signal on the network to force the chips into the bootloader or even something like a timer that detects a break condition on the network and resets the chip. For that matter some UARTs will do that so no external hardware required.


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Rob
48  Using Arduino / Project Guidance / Re: Can you sniff RS2332 Data? on: September 06, 2014, 05:24:02 pm
Yeah ok.

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Rob
49  Using Arduino / Project Guidance / Re: Can you sniff RS2332 Data? on: September 06, 2014, 09:33:19 am
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I know that if the RS232 Data is real RS232 then I will need to push it through a MAX232 or similar. But we can just ignore that I think for the moment.
How can you ignore +-12v on an Arduino pin?

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Or should I actually have the RS232 Route to the Arduino and then setup a second serial port on the arduino to send the data to the external display?
No, just tap the existing wire as drawn, but see previous question.

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Rob
50  Development / Other Software Development / Re: How to change rs-232 port mode to half-duplex? on: September 06, 2014, 05:42:06 am
That shield uses a MAX232 transceiver, that chip is not able to disable the transmitter so no it is not possible to do half-duplex with that shield.

If you find an RS232 transceiver that can tri-state the driver (I can't think of one off hand, maybe the LTC2870/LTC2871) then as Westfw says you can implement half duplex yourself.

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Rob
51  Using Arduino / Microcontrollers / Re: SN74LS86 Pinout on: September 06, 2014, 01:31:50 am
I guess they were pulling your leg eh smiley

A "gate" typically has 2 inputs (although can be more) and one output and the output is high or low according to the levels on the inputs and the logic function of the gate. The particular chip is a "quad XOR gate", you can look that up as well.

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Rob
52  Using Arduino / General Electronics / Re: Exploding GSM shield on: September 05, 2014, 04:55:43 pm
Caps tend to do that smiley

Lucky you didn't fry the board.

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Rob
53  Using Arduino / Programming Questions / Re: Integers and Strings in the same serial message on: September 05, 2014, 04:33:25 pm
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"Fan 1" was just an example, it could be set to "Motherboard Fan" or "Front Bay Fan" or "foobar",
OK, that's different.

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Rob
54  Using Arduino / Microcontrollers / Re: SN74LS86 Pinout on: September 05, 2014, 08:01:36 am
Please VishalSubramanyam you are talking gibberish, the 86 is a quad logic gate that has nothing to do with SPI, nobody seems to know that USBasp is, you have not stated what processor you are using.

In short you are wasting everyone's time unless you can explain the problem and the hardware being used.

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Rob
55  Using Arduino / Project Guidance / Re: Arduino schematics for commercial use on: September 04, 2014, 09:23:53 pm
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Selling or marketing an unapproved, non certified product, can result in FCC fines of up to $15,000 per devise.
For people like us who may just sell a few (or even a few 100) boards don't you get around this by calling it a "prototyping device" or some such.

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Rob
56  Using Arduino / Microcontrollers / Re: Arduino Due Clone on: September 04, 2014, 09:10:51 pm
I'm not an expert on the Due but AFAIK

1. don't know
2. don't know
3. no
4. yes, there is a built-in boot loader that will boot from the UART, if you can connect to that I think this will work. This is in fact what the 16U2 dose now on the Due. You will need to "press" the erase pin/button with a FET or some such.
5. yes, by connecting the USB cable to the Native USB port, there is a USB bootloader built in to the chip.

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Rob

57  Using Arduino / Microcontrollers / Re: Multiple external signals to an Arduino on: September 04, 2014, 09:04:09 pm
Depends a little on the amount of data, frequency of transmissions and what you mean by "process them", but should be able to, especially if you have an Arduino with 2 spare serial ports like the Mega.

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Rob
58  Using Arduino / Programming Questions / Re: Write once read many possibility? on: September 04, 2014, 08:56:05 pm
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securely stored to the chip so a reader can read that specific data but nobody is able to tamper with it in any way.
When is this data to be stored? Statically at compile time or at run time?

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Rob
59  Using Arduino / Project Guidance / Re: can't receive data morethan 64byte on: September 04, 2014, 08:53:02 pm
Post your code.

But it sounds like you are filling the receive buffer (which quite by chance is 64 bytes in size) and not clearing the data in time so the remaining bytes are discarded.

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Rob
60  Using Arduino / Programming Questions / Re: Integers and Strings in the same serial message on: September 04, 2014, 06:00:57 pm
As has been mentioned above I don't see why you can't just send three bytes. The sending of stuff like "Fan 1" is a common beginner thing to do because they want the data to be human-readable, but computers don't care and it just makes life harder.

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Rob
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