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1  Using Arduino / Installation & Troubleshooting / Re: New to this need a little help. on: July 09, 2014, 11:09:07 am
Please give a link to the board you purchased - there are a lot of Chinese 'clones' that do not use the ftdi chip.

the first link is my main board and the second link is my ethernet board.

http://www.ebay.com/itm/380881866999?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649

http://www.ebay.com/itm/221378519546?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649


The USB/Serial interface chip is a CH340. Never heard of it and that's why you have problems.

The correct driver is in here: http://wch-ic.com/product/usb/ch340.asp
2  Using Arduino / Installation & Troubleshooting / Re: Retrieve code from Arduino on: July 09, 2014, 11:05:00 am
If the ATmega is not locked you can read the hex file (machine code) but not the source code.
3  Using Arduino / Installation & Troubleshooting / Re: I think my Arduino Nano is internally short-circuited between 5V and Ground on: July 09, 2014, 10:57:37 am
we discovered that the 5V pin was short-circuited to the GND, even without anything connected to the board.

That's bad news because probably it's a dead ATmega.

This issue might be caused by the voltage regulator while using the 12V battery. It might have fried and passed the 12V directly into the 5V line.

You can debug the problem by doing the following:

1) remove the voltage regulator and check if the short circuit still exists in the board. If not, the regulator is fried. If the short circuit still exists it might be another component.

2) remove the ATmega and check if the short circuit still exists in the board. If not, the ATmega is fried. If the short circuit still exists it might be another component.

3) Remove the FTDI and do the same...

4  Using Arduino / Installation & Troubleshooting / Re: Arduino nano (328p) low PWM O/P on: July 09, 2014, 09:45:22 am
Are you using the output as PWM? Maybe you set it as a 50% duty cycle?

However I believe the problem is in the code. Maybe you're turning on and off the LED to fast simulating a PWM output.

Please post your code
5  Using Arduino / Installation & Troubleshooting / Re: Board not working after one day of use on: July 07, 2014, 01:58:53 pm
if just the microcontroller is broken, can that part of the board be replaced?

If people can get new hearts your arduino board can get a new uC.

If its a DIP, just pop it out and stick a new one.

If it's a TQFP, then you need good soldering skills and good flux.

Don't forget that you need to reflash the bootloader.

However I believe that the uC is not dead.

Good luck.
6  Using Arduino / Installation & Troubleshooting / Re: Board not working after one day of use on: July 07, 2014, 11:57:46 am
A few things you can do:

- Reboot PC
- Make sure you select on arduino IDE the right COM port.
- Make sure you select the right board
- Make sure you' selected the right programmer (Arduino as ISP)
- Reflash the correct bootloader (I believe you need an USBasp and select USBasp as programmer)

- Also, never connect a LED without a resistor in series. If you do that the output port will be in short-circuit.
Ohms law is your friend.

Good luck
7  Using Arduino / Networking, Protocols, and Devices / Re: Strange behavior of rf 433mhz modules in simple transmitter Receiver circuit on: July 07, 2014, 11:35:27 am
@Betomax

Still its not working. I tried at 1200 bps but the receiver dint receive any data. smiley-sad

Please help me out.

Are the modules very far away from each other? Try again with the modules very close.

After confirming they are communicating, slowly move them away.

Also, don't forget to solder an antenna on both modules.

I also recommend to develop an CRC algorithm because I experienced lots of missing and corrupt data.
8  Using Arduino / Installation & Troubleshooting / Re: blown up arduino uno on: July 07, 2014, 10:53:32 am
upon closer inspection some of the copper track was actually blasted off the pcb...

If the copper track was blasted off, I can imagine the war that happened inside the FTDI and ATmega.
9  Using Arduino / Installation & Troubleshooting / Auto reset problem on ATmega328P on: July 07, 2014, 06:11:25 am
I am using a USB-SERIAL FTDI232RL converter on a breadboard with an ATMEGA328P to upload sketchs without any trouble.

The hardware is just the ATMEGA328P, a couple shift registers and LEDs. I also add the ability to program it with ICSP.

The reset circuit is a 100nF ceramic capacitor in series with the DTR line and a 10kOhm pull-up resistor, that is:



I sent the PCBs to production on ITEAD Studio and everything works fine (including the ICSP) except the USB-serial programming.

What can be causing this trouble?
- Noise?
- The capacitor being 2cm away from the uC reset pin?
- Using a 0805 SMD 100nF ceramic capacitor?

I used an oscilloscope to watch the reset swing and it was incredible fast. I believe that the signal didn't reach 0V.

What can I do to solve this problem?

Thanks
10  Using Arduino / Project Guidance / Re: Which battery for this project? on: April 29, 2014, 03:55:45 pm
I don't think button cells can provide anything close to enough current.

You can get small LiPo cells - a single cell produces 3.6v. However they can go on fire if they are not charged carefully. HobbyKing's website has a lot of them.

Apart from that you probably need to use regular Alkaline of NiMh cells.

How many amp-hrs does your project need?

...R

You're right and I'll try another approach.

This board is to impress someone and it was intended to be used without any external power supply. The idea was wrap the package and see it working smiley-wink

So, I really needed a cheap/small/slim solution, however powering up a board like this is impossible with coin cells.

The solution I decided is using an USB plug into the board and power it up using an USB port. :/

Let's see if this solution creates the impression I want to.

Thanks
11  Using Arduino / Project Guidance / Which battery for this project? on: April 26, 2014, 11:50:39 am
Hi guys,

I am building a project with an ATmega328P (TQFP) running at 1MHz, 2x 595 shift registers, LM60 temp sensor and 14 SMD 1206 LED.

The PCB can't be bigger than 90x50mm and the battery must be the small and slimmest possible.

I tried using a button 3v Volt cell but I can't power up the board.

Do you guys have any cheap, small and slim battery solution?

Thanks.
12  Using Arduino / General Electronics / Re: I2C pull-ups resistors. on: April 21, 2014, 10:45:36 am

Did some poking; this is the current link: http://www.dsscircuits.com/index.php/articles/47-effects-of-varying-i2c-pull-up-resistors

I suppose I'll add some resistors after all. :x

Great explanation. Thank you so much.
13  Using Arduino / LEDs and Multiplexing / Re: 595 Shift Registers on: April 07, 2014, 10:26:40 am
Well... I found out the solution:

Using a pullup resistor into the OE line and only when that uC port goes down, the outputs are enable.

Thank you so much.
14  Using Arduino / LEDs and Multiplexing / 595 Shift Registers on: April 07, 2014, 10:23:53 am
Hey guys!!!

I am experiencing an issue regarding shift registers and its "ability" to randomly (or last shift register state) activate loads.

This issue occurs when I reset the arduino.

If I use an I/O port into the Output Enable pin and at the startup function I'll put that OE pin at 5V can I control this randomness?

Thanks





15  Using Arduino / General Electronics / I2C pull-ups resistors. on: February 05, 2014, 09:25:59 am
Hey smiley

When using the arduino's i2c ports (4/5) is it need to use external pull-up resistors?

As far as I know if the wire library is being used the internal pull-ups are automatically enabled.

Thanks
 
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