Difference between revisions of "LED Matrix"

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 +
We have 8 LT1441M display modules that have been donated by [[User:Msemtd|Michael Erskine]].
 +
[[User:Lwk|'RepRap' Matt]] started working on getting Arduino talking to the displays.
 +
 
[[Media:LT1441M Datasheet.pdf|Datasheet]]
 
[[Media:LT1441M Datasheet.pdf|Datasheet]]
  
Line 5: Line 8:
 
[https://github.com/NottingHack/LED-Matrix-board Git Hub Repo]
 
[https://github.com/NottingHack/LED-Matrix-board Git Hub Repo]
  
−
[[Category:Projects]]
+
= Talking to the Displays =
−
[[Category:Future Projects]]
+
 
 +
The displays use shift registers in order to control the led's.
 +
There are 256 LED's per panel, that 2048 in total.
 +
Data is shifted out over the GSI and RSI pins in time with the CLOCK.
 +
After clocking out all 2048 pixels of LATCH the data.
 +
 
 +
Below is an modifed version of the Arduino shiftOut that out puts data on both GSI and RSI pins for the same clock cycle
 +
 
 +
<syntaxhighlight lang="cpp">
 +
void shiftOutDual(int dataPin, int dataPin1, int clockPin, int bitOrder, int val, int val1){
 +
 
 +
int i;
 +
 
 +
for (i = 0; i < 8; i++)  {
 +
if (bitOrder == LSBFIRST) {
 +
digitalWrite(dataPin, !!(val & (1 << i)));
 +
digitalWrite(dataPin1, !!(val1 & (1 << i)));
 +
}else{
 +
digitalWrite(dataPin, !!(val & (1 << (7 - i))));
 +
digitalWrite(dataPin1, !!(val1 & (1 << (7 - i))));
 +
                }
 +
 
 +
digitalWrite(clockPin, HIGH);
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digitalWrite(clockPin, LOW);
 +
 
 +
}
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 +
}
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</syntaxhighlight>
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 +
 
 +
 
  
  
Line 13: Line 47:
 
Power: JST VH connector: http://www.jst.co.uk/productSeries.php?pid=133
 
Power: JST VH connector: http://www.jst.co.uk/productSeries.php?pid=133
  
−
[[File:Led-matrix-con2.jpg]]
+
[[File:Led-matrix-con2.jpg|thumb]]
 +
 
 +
{| class="wikitable"
 +
|-
 +
! Pin No.
 +
! Name
 +
! Function
 +
|-
 +
| 1
 +
| V1
 +
| Power supply for LED (red)
 +
|-
 +
| 2
 +
| GND1
 +
| Ground for IC
 +
|-
 +
| 3
 +
| VDD
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| Power supply for IC
 +
|-
 +
| 4
 +
| GND2
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| Ground for LED
 +
|-
 +
| 5
 +
| V2
 +
| Power supply for LED (yellow-green)
 +
|-
 +
|}
  
 
Data: JST XH connector: http://www.jst.co.uk/productSeries.php?pid=136
 
Data: JST XH connector: http://www.jst.co.uk/productSeries.php?pid=136
  
−
[[File:Led-matrix-con1.jpg]]
+
[[File:Led-matrix-con1.jpg|thumb|]]
 +
 
 +
{| class="wikitable"
 +
|-
 +
! Pin No.
 +
! Name
 +
! Function
 +
|-
 +
| 1
 +
| GSI
 +
| Serial data yellow-green
 +
|-
 +
| 2
 +
| /GAEO
 +
| Output enable for yellow-green
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|-
 +
| 3
 +
| LATCH
 +
| Latch contents of shift register
 +
|-
 +
| 4
 +
| GND1
 +
| Ground of IC
 +
|-
 +
| 5
 +
| CLOCK
 +
| Clock Signal for data (read on L->H)
 +
|-
 +
| 6
 +
| /RAEO
 +
| Output enable for red
 +
|-
 +
| 7
 +
| RSI
 +
| Serial data red
 +
|-
 +
|}
 +
 
 +
 
 +
 
 +
[[Category:Projects]]

Revision as of 20:46, 13 April 2011

We have 8 LT1441M display modules that have been donated by Michael Erskine. 'RepRap' Matt started working on getting Arduino talking to the displays.

Datasheet

Pictures

Git Hub Repo

Talking to the Displays

The displays use shift registers in order to control the led's. There are 256 LED's per panel, that 2048 in total. Data is shifted out over the GSI and RSI pins in time with the CLOCK. After clocking out all 2048 pixels of LATCH the data.

Below is an modifed version of the Arduino shiftOut that out puts data on both GSI and RSI pins for the same clock cycle 

void shiftOutDual(int dataPin, int dataPin1, int clockPin, int bitOrder, int val, int val1){

	int i;

	for (i = 0; i < 8; i++)  {
		if (bitOrder == LSBFIRST) {
			digitalWrite(dataPin, !!(val & (1 << i)));
			digitalWrite(dataPin1, !!(val1 & (1 << i)));
		}else{
			digitalWrite(dataPin, !!(val & (1 << (7 - i))));
			digitalWrite(dataPin1, !!(val1 & (1 << (7 - i))));
                }

		digitalWrite(clockPin, HIGH);
		digitalWrite(clockPin, LOW);

	}

}



Connectors

Power: JST VH connector: http://www.jst.co.uk/productSeries.php?pid=133

Led-matrix-con2.jpg
Pin No. Name Function
1 V1 Power supply for LED (red)
2 GND1 Ground for IC
3 VDD Power supply for IC
4 GND2 Ground for LED
5 V2 Power supply for LED (yellow-green)

Data: JST XH connector: http://www.jst.co.uk/productSeries.php?pid=136

Led-matrix-con1.jpg
Pin No. Name Function
1 GSI Serial data yellow-green
2 /GAEO Output enable for yellow-green
3 LATCH Latch contents of shift register
4 GND1 Ground of IC
5 CLOCK Clock Signal for data (read on L->H)
6 /RAEO Output enable for red
7 RSI Serial data red
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