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16  Using Arduino / Sensors / Wire issue with ADXL345 on: February 01, 2013, 09:50:41 am
Hi,

I have an arduino UNO with an accelerometer ADXL345, which works through the TWI bus.

Using the Enerlib library to sleep arduino,  if it is slept in PowerDown mode, I can't wake it by an  interruption from the accelerometer.

Only works (with an interruption) when:
- Watchdog finishes every cycle but not when is completely  slept.
- If I disconnect the accelerometer, the arduino always awakes.

* I'm working with internal interruption from digital pins. It's tested that it works fine, also with external ones.

Probably, the microcontroller disable the TWI bus when it is in PowerDown mode, and there is an issue there, blocking the accelerometer to send the interruption.

Could anyone help me, please??
17  Using Arduino / Networking, Protocols, and Devices / Re: ZB-Pro Router issue in large network on: February 01, 2013, 03:03:25 am
Thanks Jack!

I'm going to configure my devices, and I'll try this!

I never remove coordinator but when I switch off the router for a long time (simulating battery breaks down), it needs some time to add again to the network. So, I'm going to check the default params for any change.

18  Using Arduino / Networking, Protocols, and Devices / ZB-Pro Router issue in large network on: January 31, 2013, 06:48:28 am
Hi,


I'm developing a large Zigbee network with a coordinator, several routers and more end-devices.

I tried to install routers near the coordinator as much as I could,, but not all of them are at this situation. I have some routers connect between themselves, but not with coordinator directly.

As all my routers devices work with liPo or li-Ion batteries, when any of the router, without line-of-sight, exhausts the battery, the network breaks down.

I said that because routers have to detect coordinator in the first time it begin to work, so if battery goes down, when I change it, I have to move my device all along the network and come back.


Is there any option for maintaining the network parameters even if the coordinator isn't near enough??

Could it be as simply as modify 'NW', 'JV', 'NT' or 'NO' parameters??


Thanks in advance!

Regards.
19  International / Español / ZB-Pro router on: January 31, 2013, 06:47:37 am
Hola,


Estoy desarrollando una gran red Zigbee con un coordinador, varios routers y más dispositivos finales.

He intentado instalar routers cercanos al coordinado,r tanto como pude, pero no todos ellos se encuentran en esta situación. Tengo algunos routers conectados entre sí, pero no con el coordinador directamente.

Como todos mis routers dispositivos funcionan con baterías LiPo o Li-ion, cuando cualquiera de los router, sin línea de visión directa, agota la batería, la red se rompe.

Debido a que los routers tienen que detectar el coordinador la primera vez que empiezan a trabajar, si la batería se cae, cuando la cambio, tengo que mover mi dispositivo a lo largo de la red y volver.


¿Hay alguna opción para mantener los parámetros de red, incluso si el coordinador no está lo suficientemente cerca?

¿Podría ser tan simple como modificar 'NO', 'JV', 'NT' o 'NO' parámetros??



Gracias de antemano!

Recuerdos.
20  International / Proyectos / Re: Mejorar la precisión/resolución para medir una malla resistiva on: January 17, 2013, 02:04:49 am

- La resolución del sistema varía en un rango entre miliOhm y Ohm. Estará entre [1-20] Ohm. Por lo que colocando un Pull-up lo mas pequeño posible, de 1 Ohm. He de ser capaz de medir los miliOhm de variación, que se producen al cortar la malla.

- Conexión Kelvin (4 cables) + AO instrumentación + conversor externo de mayor resolución. ¿Podrías adjuntar un esquema? ¿O detallar la configuración para el AO?
21  International / Proyectos / Re: Mejorar la precisión/resolución para medir una malla resistiva on: January 14, 2013, 02:41:05 am
Hola,

estamos hablando de una malla de 1m2 de sección de tamaño máximo.

Aunque la medición luego sería sobre un tamaño más pequeño, nos hemos ido a los más grande posible (peor caso) para desde ahí mejorar los resultados obtenidos.

22  Using Arduino / General Electronics / Re: Best accuracy to measure resistor variation on: January 11, 2013, 03:04:23 am
Hi,

thanks to all!!

- The pull-up resistor is low enough to measure the mesh resistance, if I have a high resolution measurer, about [1-20] Ohms.
- I'll study the RC circuit, but I think it will need a very large capacitor for this project, so it will be difficult. However I'm going to make a test with it.
- Arduino will have a lithium battery as power source. So, it will take measurements each 10 minutes. Not a constant measure will be implemented.
- The mesh resistance is under 1 KOhm, but I can assure you the real value because it depends on the mesh size.

Regards!!
23  International / Proyectos / Mejorar la precisión/resolución para medir una malla resistiva on: January 11, 2013, 02:50:24 am
Hola,

estoy intentando desarrollar un medidor de resistencia con alta precisión para arduino. Voy a explicar de la mejor manera que pueda mi proyecto y dudas.

- Tengo un arduino Mega2560, y una malla de cable grande (la llamaremos 'malla' solamente a partir de aquí).
     * Esta malla tiene gran conducitivdad, y poca resistividad, como parámetros principales.
- Conectando la malla con una resistencia de pull-up de bajo valor (el voltaje de entrada es de 5V, tomado del arduino), montando un divisor de tensión con ellos (la malla va conectada a la tierra del arduino).
- Tomaré medidas desde el divisor de tensión con arduino, de forma que pueda obtener el valor de resistencia de la malla.
- El objetivo es medir la variación mínima de resistencia, en caso de que la malla sea cortada.

Hay alguna forma de mejorar la precisión/resolución de arduino para llevar este proyecto a cabo??

Saludos!!
24  Using Arduino / General Electronics / Best accuracy to measure resistor variation on: January 10, 2013, 09:19:24 am
Hi,

I'm trying to develop a resistor measurer with high accuracy for arduino. I'm going to explain the best I can my project and my doubts.

- I have an arduino Mega2560, and a long wire mesh (aka. mesh).
     * This mesh has a great conductivity also low resistance parameters.
- Connecting the mesh with a low value pull-up resistor (input voltage is 5V from Arduino), building a voltage divider with them (the mesh is connected to ground from arduino).
- I take measurements from the voltage divider with arduino, so I can know resistor mesh values.
- The target is measure the minimun variation of resistance, in case the mesh will be sliced.

Is there any way to increase arduino accuracy/resolution so this project will be succesful??

Regards!
25  Using Arduino / Programming Questions / Re: Interruption meanwhile MCU is sleeping on: December 11, 2012, 02:22:13 am
Hi,

thanks johnwasser.

you were right, I read in Atmega datasheet about this.
- Only INT0:3 wake up MCU by non edge-triggered (Rising, Falling, Change) interrupts.
- And INT4:7 wake up MCU by level (High, Low) interrupts.

But I was working with interruption 5 (pin 18 in Arduino Mega2560), and the fact is MCU wake up with 'Falling' mode.

After reading datasheet, I also understand that MCU need a some cycles  plus a time (14CK [I don't know which is CK]) to start-up.

Now, I'm still trying to know why is counting less than the number of interruptions (it could be because of the time of level has to be hold before the MCU wake up and can trigger the interruption).

Regards.
26  Using Arduino / Programming Questions / Interruption meanwhile MCU is sleeping on: December 05, 2012, 10:00:15 am
Hi,

I'm working with interruptions and sleep mode in Arduino Mega2560.

I've created a simply interruption function that increases a counter when interruption is attached.
- When the MCU is awake, it works fine. The counter increases as the same way the interruption is done.
- When the MCU is asleep, it doesn't work. The counter always counts less than the real number of interruptions.

I tried several paths to solve this, but it doesn't matter, even saving the data at EEPROM and reading it every interruption.

- I'm using interruption 5 (pin 18):
Code:
attachInterrupt(5, count, FALLING);

My code is like shown:

Code:
void count() {
   init_int_time = millis();
   
   Counter = EEPROM.read(20);
   
   if (init_int_time - last_int_time > 200) {
     Counter++;     
     last_int_time = init_int_time;
   }
   
   EEPROM.write(20, Counter);
}

Could some give me some help with this??

Thanks!!

Regards.
27  Using Arduino / Installation & Troubleshooting / Re: XBee Explorer USB on Linux System on: October 31, 2012, 02:57:48 am
Problem resolved!!

It was the fridge EM pulses.

 smiley-mr-green
28  Using Arduino / Microcontrollers / Re: Arduino Mega2560 as ISP to program another Arduino Mega2560 on: October 09, 2012, 02:40:21 am
Ok, first of all, thanks!!

I'll try to be more explicit.

1) I mean that when I try to upload the code, I follow next steps:
  - Check Port.
  - Check target board (Arduino Mega2560).
  - Check programmer (Arduino as ISP).
  - With an Arduino Mega2560 and the ArduinoISP code uploaded, I program the target board. I see how Tx & Rx leds of programmer board blink, but in the target board I don't see anything.
  - In the bottom terminal of the IDE it is all right, so I understand the proccess worked fine.

2) Maybe I have done a mistake with Reset pin, I connect the SS pin (53) to the 'Reset' labeled one in the target board (I thinked is pin 30 in microcontroller).

3) At the moment, I'm only trying to use an Arduino Mega2560 as ISP to program another Arduino Mega2560 board.

I'm going to continue working on this issue, but if you could help it woul be great!

Thanks again!
29  Using Arduino / Microcontrollers / Arduino Mega2560 as ISP to program another Arduino Mega2560 on: October 08, 2012, 05:12:13 am
Hi,

I'm trying to use an Arduino Mega2560 as ISP to program another Arduino Mega2560.

After reading a lot of info about, I tried several different ways to connect the arduinos but it didn't work. So, I tell you my attempts in case you can help me. Even I tried to use an Arduino Uno to work as ISP or to upload the code to it, but it didn't work either.

First of all, I upload to one of them (Arduino Mega2560) the ArduinoISP example, and select programmer 'Arduino as ISP'. Select the right board to upload the code and the port.

1- I connect as in the Arduino ISP example (http://arduino.cc/es/Tutorial/ArduinoISP) but optimized for the Mega.
MISO (50)  -  MISO   (50)
MOSI (51)  -  MOSI   (51)
SCK   (52)  -  SCK     (52)
SS      (53)  -  Reset  (30)

2- I tried to connect the wires in the opposite way.
MISO (50)  -  MOSI   (51)
MOSI (51)  -  MISO   (50)
SCK   (52)  -  SCK     (52)
SS      (53)  -  Reset  (30)

3- Also with Arduino Uno, I changed to fix the wires to Arduino Uno pin configuration.
MISO (50)  -  MISO   (12)
MOSI (51)  -  MOSI   (11)
SCK   (52)  -  SCK     (13)
SS      (53)  -  Reset  (7)

4- And the other way, Arduino Uno as ISP.
MISO (12)  -  MISO   (50)
MOSI (11)  -  MOSI   (51)
SCK   (13)  -  SCK     (52)
SS      (7)  -  Reset  (30)

I can't do anything. I read about plug a 10 uF capacitor between 'reset' and 'gnd' after upload Arduino ISP, but this didn't work either.

Could any help me?? It's important to solve this problem.

* I'm working under Ubuntu environment, with Arduino IDE 1.0.

Thanks!
30  Using Arduino / Installation & Troubleshooting / XBee Explorer USB on Linux System on: October 03, 2012, 03:21:14 am
Hi,

I'm working with this XBee Explorer USB and I found a strange behaviour.

When it's connected too much time, it stops to receive data. It is connected in my PC, at the same port, but data doesn't come into the serial monitor. It seems like the Explorer 'sleeps' after some time. I tried with several units and all of them make the same thing.

Is there any trick or hardware configuration to avoid this?? I need to receive data each 12 hours.

Thanks!
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