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1  Using Arduino / Networking, Protocols, and Devices / Mifare RC522 reader on: April 24, 2014, 01:39:42 pm
Hello all

I bought a Mifare RC522 reader card on ebay a while ago.
Now i digged it out from the drawer and trying to use it.

I found rfid library that is said to be compatible for the RC522.

But there is something i dont understand.
The examples define the following pins:
  • Reset
  • SPI SS

But the card i have don't have any SS pin.

Is SDA same as SS ?
Or do I need another library?

Any help will be appreciated

Best regards
2  Using Arduino / Networking, Protocols, and Devices / Arduino WiFi shield on: February 04, 2014, 02:33:39 am
After upgrading to IDE 1.5.2 I am not able to get the Official Arduino WiFi Shield (R3) up and running.

I followed the instructions at as follows:
  • Downloaded Flip 3.4.7
  • connected programming jumper
  • batchisp.exe -device AT32UC3A1256 -hardware usb -operation erase f memory flash blankcheck loadbuffer /Arduino/hardware/arduino/firmware/wifishield/binary/wifi_dnld.elf program verify start reset 0
  • pressed reset on wifi shield
  • batchisp.exe -device AT32UC3A1256 -hardware usb -operation erase f memory flash blankcheck loadbuffer /Arduino/hardware/arduino/firmware/wifishield/binary/wifi_dnld.elf program verify start reset 0
  • disconnected programming jumper

I then opened the example code WifiWebServer and changed the SSID and WPA2 password.
I also added code for printing out Wifi firmware version: Serial.println(WiFi.firmwareVersion());

When I upload the code, it connects to my wifi network.
It answers on ping
But gives no reply in browser, and "new client" is never written to monitor.

Here is the output I get in serial monitor:
Attempting to connect to SSID: kremlings
Firmware 1.1.0
SSID: kremlings
IP Address:
signal strength (RSSI):-39 dBm

Appreciate all the help I can get

Best regards
3  Using Arduino / Installation & Troubleshooting / AT32UC3A usb driver Windows 7 64 bit on: February 03, 2014, 04:04:33 am
Hello all
I am trying to follow the description for updating firmware on the Wifi Shield.

But I am not able to connect to the shield using usb.

Device manager tells me:
The drivers for this device are not installed. (Code 28)
There is no driver selected for the device information set or element.
To find a driver for this device, click Update Driver.

I tried to browse for the driver in \Program Files (x86)\Arduino
but it does not find any suitable driver.

If someone can give me a hint about how to find and install the driver it would be great

Thanks in advance

4  Using Arduino / Installation & Troubleshooting / Problem using USB communication while Vin is powered with external PSU on: March 21, 2013, 03:39:42 am
Hello all
I am having a problem with usb communication to pc if 12V power is connected to Vin pin on Arduino Nano.

Windows keep saying that there is something wrong with the attached USB device.

Is there a work-around for this?

Any help is appreciated

Best regards
5  Using Arduino / Microcontrollers / Bootloader for Nano on: January 10, 2013, 07:00:23 am
Hello all
I got an Nano 3.0 clone, but it is not having a bootloader installed.

When I look into the hardware/bootloaders folder, I see there are many different to choose from.

If someone could tell me which hex file to install, I think I can manage to install it myself.

Best regards
6  Using Arduino / Project Guidance / Re: RS485 Shield on: November 05, 2012, 08:54:16 am
Thank you  smiley
7  Using Arduino / Project Guidance / RS485 Shield on: November 05, 2012, 04:16:11 am
Hello all
I just bought a RS485 shield, and have a general question about the RX/TX pins.

I see that my shield is connecting to the RX/TX pins on the Arduino.

Will this conflict with the serial communication to my pc?

Thankful for any guidance

Best regards

8  Using Arduino / Programming Questions / Re: Error in String.getBytes() ? on: October 12, 2012, 04:09:04 am
I have the same problem also with toCharArray() method

Best regards
9  Using Arduino / Programming Questions / Error in String.getBytes() ? on: October 12, 2012, 04:05:38 am
I am a Java developer, so I can't brag about my C++ experience.

I am using Arduino IDE 1.0.1 for Windows

Example code:
void setup(){
  Serial.println("Serial started");

void loop(){
  String message = "Hello World";
  byte bytes[message.length()];
  message.getBytes(bytes, message.length());
  Serial.print(message+" length="+message.length());
  Serial.print(" (");
  for (int i = 0; i < message.length(); i++){
    if (i > 0){
      Serial.print(" ");

This gives the following output:
Hello World length=11 (72 101 108 108 111 32 87 111 114 108 0)

As you can see, the last byte is always 0

If I am doing something wrong, please let me know

Best regards
10  Development / Suggestions for the Arduino Project / Re: ESD Safety on: August 16, 2012, 08:19:20 am
Noone is able to see if a component is damaged by ESD.
If it left a brown mark with bad smell, then it would be easy.

Most users probably expose the board with even more ESD (laying on ungrounded tables etc).

How many cent would it cost to wrap the boards safely?


11  Development / Suggestions for the Arduino Project / Re: ESD Safety on: August 16, 2012, 07:52:50 am

You never know where a 20 000 Volt static spark hits.
If it hits the common ground then you may be lucky.

Ship the boards wrapped in ESD safe materials and show the world that you care about quality.
12  Development / Suggestions for the Arduino Project / ESD Safety on: August 16, 2012, 06:38:24 am
Hello all
I just received a brand new Arduino UNO R3

It came beautiful packaged inside a cardboard box together with some plastic covered stickers.

Since we are talking about unshielded electronics, and a microcontroller I was expecting to receive it wrapped in ESD safe materials.

There are big chances that the microcontroller is already damaged even before I open the box.

13  Using Arduino / Networking, Protocols, and Devices / Denon receiver control on: October 17, 2011, 11:12:41 am
Hello all
I am quite new to electronics, but am quite experienced programming with Java.

I own a Denon AVR-2808 Surround receiver.
It has a RS232 interface which I believe can be used for something useful.

The attached pdf describes the available commands and events that can be sent and received over RS232C

It would be fun to make a control interface using Arduino. It could be a webserver interface or a touch screen  smiley

I guess I need to make a shield for attaching a serial cable.
This is the pinout described:
Connector type: DB-9pin female type, slave straight connection (DCE type)
( 1pin : GND , 2pin : TxD , 3pin : RxD , 5pin : Common(GND) , 4,6,7,8,9pin : NC )

The communication format is as follows:
Synchronous system : Tone step synchronization
Communication system : A half duplex
Communication speed : 9600bps
Character length : 8 bits
Parity control : None
Start bit : 1 bit
Stop bit : 1 bit
Communication procedure : Non procedural
Communication data length : 135 bytes (maximum)

Can anyone guide me how I can make the RS232C shield and how to setup the communication?

Best regards
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