LED Matrix: Difference between revisions
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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] | ||
= 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 | |||
<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); | |||
digitalWrite(clockPin, LOW); | |||
} | |||
} | |||
</syntaxhighlight> | |||
| 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 | |||
| 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 | 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 | |||
|- | |||
| 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.
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
| 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
| 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 |