LED Dot Matrix

[teivel]

Beside is the dot matrix I'm using . The version of flowcode is V3.6.11.53. My purpose is find out the output for every single LED. SO i try to light up each col and row first. This is the output i found for COL0-7 (due to using demo version of flowcode, the outputs can be used are limited ). Output for col6 and 7 are 191 and 127. When i try to light up row0 with the output of 254 at port A and 0 at port B, the led at row0 light up but also leds at row5,6 & 7

please help

 

[Ian Rogers]

Not many here use flowcode...
Are your outputs inverted by the transistors.... ( I assume so as you are using binary "11111110" ) but then you are setting port b to 0... There are only 8 transistors, so shouldn't only one port be inverted?

Have you a schematic of that LED board?

If you have the rows on port A and the columns on port B you should be selecting 255 on port B to light all the row..

The other thing to check is that your pins are outputs and any analogue modules are turned off... One more thing... Some DEV boards use the pins elsewhere so that can affect your results... Just make sure nothing else on the board is using these outputs.

 

[teivel]

Hi there, for your information the output is inverted as shown in image provided ( to light up bit 0 , u need to enter the output of bit1 to7 ). I don't know how to use binary in flowcode. Btw, i use 0 output in port b so that none of the led in col0 to col7 will be selected which means all led in col0 - col7 will light up ( with output of 255, none of the led in col0-7 light up since the output is inverted . Actually both port A and B are inverted based on my experience. I tried light up bit 0 in row0 and col0 with output of 1 and both led in col0 and row0 remain unchanged ( it didnt light up ). I think the output is nt affected by things u mentioned because i tried erased it using ppp. glads

 

[Ian Rogers]

Does flowcode support hex? Hex is shorthand for binary... Dec 254 = Binary 11111110 = Hex 0xfe ( &HFE )

 

[teivel]

I not sure if it does. In fact, the 0Xfe light up the leds. Can u talk more about that

 

[Ian Rogers]

oxFE is short for binary.

0000 = 0
0001 = 1
0010 = 2
0011 = 3
0100 = 4
0101 = 5
0110 = 3
0111 = 6
1000 = 8
1001 = 9
1010 = A
1011 = B
1100= C
1101 = D
1110 = E
1111 = F

Therefore 254 = 1111 1110 = 0xFE

 

[teivel]

i dont understand at all..but thx = =

 

[Ian Rogers]

Which part do you not understand? When programming it's wise to learn hexadecimal... It can help you quite a bit.

for example if I send 0xAA to the B port I know that each other pin will be high as its binary 10101010.. it make life so much easier.

 

[teivel]

I dont understand how do you calculate the binary code of each letter... So u mean when u send 0xAA to port B the led at col7, 5, 3 and 1 only will light up? But how about output at port A ?