Photoduino Shield was designed when the last version of Arduino was “Arduino Duemilanove”. Some time ago appears in the scene “Arduino UNO”. Photoduino is in theory fully compatible with this new model, but in the second release of Arduino UNO, the “R2 version”, a problem was detected with the power up.
The problem is when you upload the firmware to the board, all is fine, but when you power up again the board, the firmware isn’t start correctly and you will see some square boxes in the LCD display and no beep on the speaker.
To fix this problem, a solution was found. You only need to solder a diode 1N4148 between the 5V pin to the RESET pin at the Photoduino Shield or, if you prefer, in the Arduino board.
Be sure to connect in right position. The black band in the diode indicates the cathode and the other side is the anode. You need to connect the cathode to the VCC (5v) pin and the anode to the RESET pin of Arduino or the same pins in the Photoduino Shield. See the next picture to check the right position.
Take care soldering the diode and do it with patience.
After fix is done, when you connect arduino to the power or USB, the firmware will run correctly.
This post is also available in: Spanish
Queria felicitarte por el manífico trabajo y la presentación de este nuevo blog. Hecho de menos el castellano como de como de información, pero entiendo que mantener los dos lenguajes es una labor tediosa que lleva su tiempo. Lo dicho enhorabuena.