Hi all,
i am a newbie getting familiarized with controlling led matrix display 8x8 using two register 595(project in beginning arduino book), however i can't seem to light up the 7th column, so i removed all the wires started all over again now the 7th did light up but the 8th got angry and did not light up.
My tests :
** components on breadboard : 1 x resistor, 1 x display matrix
lighting up every led individually, 3V->resistor->columnX, rowY->ground : OK.
** components on breadboard : 1 x resistor, 1 x display matrix
all cathodes to the ground, 3V->resistor->anodeX
all columns did light up successfully : OK
** components on breadboard : 8 x resistors, 1 x display matrix
all cathodes to ground, all anodes to resistor to 5V, 8th column did not light up : KO
removed all the wires from the display anodes to the resistors, tried connecting the first wire with all the anodes, they did light up, but when i try the same with the eighth wire, every column does NOT light up, changed the wire, the resistor in vain, they all seem to be able to light up the columns except the eighth wire!! i checked the voltage and it is 2.96 which is fairly higher than the forward voltage of the led.
fritzing does not have 8x8 display, just assume it is.
my led display matrix datasheet : http://www.farnell.com/datasheets/1683560.pdf
i am a newbie getting familiarized with controlling led matrix display 8x8 using two register 595(project in beginning arduino book), however i can't seem to light up the 7th column, so i removed all the wires started all over again now the 7th did light up but the 8th got angry and did not light up.
My tests :
** components on breadboard : 1 x resistor, 1 x display matrix
lighting up every led individually, 3V->resistor->columnX, rowY->ground : OK.
** components on breadboard : 1 x resistor, 1 x display matrix
all cathodes to the ground, 3V->resistor->anodeX
all columns did light up successfully : OK
** components on breadboard : 8 x resistors, 1 x display matrix
all cathodes to ground, all anodes to resistor to 5V, 8th column did not light up : KO
removed all the wires from the display anodes to the resistors, tried connecting the first wire with all the anodes, they did light up, but when i try the same with the eighth wire, every column does NOT light up, changed the wire, the resistor in vain, they all seem to be able to light up the columns except the eighth wire!! i checked the voltage and it is 2.96 which is fairly higher than the forward voltage of the led.
fritzing does not have 8x8 display, just assume it is.
my led display matrix datasheet : http://www.farnell.com/datasheets/1683560.pdf