This is largely wishful thinking on my part but I recently bought a Beagleboard Rev C2, which by today’s standards is ancient. I know nothing about PCB design but I saw these LCD headers space on the board and info in the docs about an adapter board. I bought a 7" Innolux digital TFT LCD (and a touch screen, which is another matter) and am trying to figure out how the 40 pin connector on the LCD relates to the 2 x 20 pin space on the Beagle. Below are the tables for the two banks of Beagle headers and that for the 40 pin assignment of the LCD.
I notice there are 26 Os (outputs) on the Beagle and an equal number of Is (inputs) on the LCD. Do they correlate? How does one go about making the connections/correlations? Is this one of those projects that can be accomplished using a PCB from my neighbourhood electronic shop and a printer? I’ve also copied and pasted some power data on the LCD below. I’d really appreciate your patience, guidance and help, thanks.
8.14 LCD Expansion Headers (Rev C2 only)
Access is provided on the Rev C2 to allow access to the LCD signals. Table 16 shows the signals that are on the J4 connector. You will notice that the signals are not in a
logical order or grouping. This is due to the routing on the PCB where we allowed the routing to take president to get it to rout with no addition of layers to the design.
Table 16. J4 LCD Signals
Pin#
|
Signal
|
I/O
|
Description
|
- | - | - | - |
|
|
|
|
1
|
DC_5V
|
PWR
|
DC rail from the Main DC supply
|
2
|
DC_5V
|
PWR
|
DC rail from the Main DC supply
|
3
|
DVI_DATA1
|
O
|
LCD Pixel Data bit
|
4
|
DVI_DATA0
|
O
|
LCD Pixel Data bit
|
5
|
DVI_DATA3
|
O
|
LCD Pixel Data bit
|
6
|
DVI_DATA2
|
O
|
LCD Pixel Data bit
|
7
|
DVI_DATA5
|
O
|
LCD Pixel Data bit
|
8
|
DVI_DATA4
|
O
|
LCD Pixel Data bit
|
9
|
DVI_DATA12
|
O
|
LCD Pixel Data bit
|
10
|
DVI_DATA10
|
O
|
LCD Pixel Data bit
|
11
|
DVI_DATA23
|
O
|
LCD Pixel Data bit
|
12
|
DVI_DATA14
|
O
|
LCD Pixel Data bit
|
13
|
DVI_DATA19
|
O
|
LCD Pixel Data bit
|
14
|
DVI_DATA22
|
O
|
LCD Pixel Data bit
|
15
|
I2C3_SDA
|
I/O
|
I2C3 Data Line
|
16
|
DVI_DATA11
|
O
|
LCD Pixel Data bit
|
17
|
DVI_VSYNC
|
O
|
LCD Vertical Sync Signal
|
18
|
DVI_PUP
|
O
|
Control signal for the DVI controller. When Hi, DVI is enabled. Can be used to activate circuitry on adapter board if desired.
|
19
|
GND
|
PWR
|
Ground bus
|
20
|
GND
|
PWR
|
Ground bus
|
The current available on the DC_5V rail is limited to the available current that remains from the DC supply that is connected to the DC power jack on the board. Keep in mind that some of that power is needed by the USB Host power rail and if more power is needed for the expansion board, the main DC power supply current capability may need to be increased. All signals are 1.8V except the DVI_PUP which is a 3.3V signal.
Table 17 shows the signals that are on connector J5.
Table 17. J5 LCD Signals
Pin#
|
Signal
|
I/O
|
Description
|
- | - | - | - |
1
|
3.3V PWR
|
3.3V
|
reference rail
|
2
|
VIO_1V8
|
PWR
|
1.8V buffer reference rail.
|
3
|
DVI_DATA20
|
O
|
LCD Pixel Data bit
|
4
|
DVI_DATA21
|
O
|
LCD Pixel Data bit
|
5
|
DVI_DATA17
|
O
|
LCD Pixel Data bit
|
6
|
DVI_DATA18
|
O
|
LCD Pixel Data bit
|
7
|
DVI_DATA15
|
O
|
LCD Pixel Data bit
|
8
|
DVI_DATA16
|
O
|
LCD Pixel Data bit
|
9
|
DVI_DATA7
|
O
|
LCD Pixel Data bit
|
10
|
DVI_DATA13
|
O
|
LCD Pixel Data bit
|
11
|
DVI_DATA8
|
O
|
LCD Pixel Data bit
|
12
|
NC
|
|
No connect
|
13
|
DVI_DATA9
|
|
LCD Pixel Data bit
|
14
|
I2C3_SCL
|
I/O
|
I2C3 Clock Line
|
15
|
DVI_DATA6
|
O
|
LCD Pixel Data bit
|
16
|
DVI_CLK+
|
O
|
DVI Clock
|
17
|
DVI_DEN
|
O
|
Data Enable
|
18
|
DVI_HSYNC
|
O
|
Horizontal Sync
|
19
|
GND
|
PWR
|
Ground bus
|
20
|
GND
|
PWR
|
Ground bus
|
The 1.8V rail is for level translation only and should not be used to power circuitry on the board. The 3.3V rail also has limited capacity on the power as well. If the TFP410 is disabled on the Beagle, then 80mA is freed up for use on an adapter card connected to the LCD signals connectors. It is not required that the TFP410 be disabled when running an adapter card, but the power should be taken into consideration when making this decision.
It is suggested that the 5V rail be used to generate the required voltages for an adapter card.
Innolux AT070TN83 V.1 Pin Assignment
TFT LCD Panel Driving Section
TTL Connector is used for the module electronics interface. The recommended model is
FH19SC-40S-0.5SH manufactured by Hirose.
Pin No.
|
Symbol
|
I/O
|
Function
|
Remark
|
- | - | - | - | - |
1
|
VLED
|
P
|
Power voltage for LED Driver
|
|
2
|
VLED
|
P
|
Power voltage for LED Driver
|
|
3
|
ADJ
|
I
|
Adjust the led brightness with PWM Pulse
|
Note 1;2
|
4
|
GLED
|
P
|
Ground for LED circuit
|
|
5
|
GLED
|
P
|
Ground for LED circuit
|
|
6
|
VCC
|
P
|
Power voltage for digital circuit
|
|
7
|
VCC
|
P
|
Power voltage for digital circuit
|
|
8
|
MODE
|
I
|
DE or HV mode control
|
Note 3
|
9
|
DE
|
I
|
Data enable
|
|
10
|
VS
|
I
|
Vsync signal input
|
|
11
|
HS
|
I
|
Hsync signal input
|
|
12
|
GND
|
P
|
Power ground
|
|
13
|
B5
|
I
|
Blue data input (MSB)
|
|
14
|
B4
|
I
|
Blue data input
|
|
15
|
B3
|
I
|
Blue data input
|
|
16
|
GND
|
P
|
Power ground
|
|
17
|
B2
|
I
|
Blue data input
|
|
18
|
B1
|
I
|
Blue data input
|
|
19
|
B0
|
I
|
Blue data input(LSB)
|
|
20
|
GND
|
P
|
Power ground
|
|
21
|
G5
|
I
|
Green data input(MSB)
|
|
22
|
G4
|
I
|
Green data input
|
|
23
|
G3
|
I
|
Green data input
|
|
24
|
GND
|
P
|
Power ground
|
|
25
|
G2
|
I
|
Green data input
|
|
26
|
G1
|
I
|
Green data input
|
|
27
|
G0
|
I
|
Green data input(LSB)
|
|
28
|
GND
|
P
|
Power ground
|
|
29
|
R5
|
I
|
Red data input(MSB)
|
|
30
|
R4
|
I
|
Red data input
|
|
31
|
R3
|
I
|
Red data input
|
|
32
|
GND
|
P
|
Power ground
|
|
33
|
R2
|
I
|
Red data input
|
|
34
|
R1
|
I
|
Red data input
|
|
35
|
R0
|
I
|
Red data input(LSB)
|
|
36
|
GND
|
P
|
Power ground
|
|
37
|
DCLK
|
I
|
Sample clock
|
|
38
|
GND
|
P
|
Power ground
|
|
39
|
L/R
|
I
|
Select left or right scanning direction
|
Note 4
|
40
|
U/D
|
I
|
Select up or down scanning direction
|
Note 4
|
I: input; O: output; P: power
Note1: ADJ adjust brightness to control Pin, Pulse duty the bigger the brighter.
Note 2: ADJ signal=0~3.3V,operation frequency:100~300Hz.
Note 3: DE Mode, Mode=”H”,HS floating and VS floating
HV Mode, Mode=”L” and DE floating
Note 4: Selection of scanning mode
3.2. Typical Operation Conditions
Item
Symbol
Values
Unit
Remark
Min.
Typ.
Max.
Power voltage
VCC
3.1
3.3
3.5
V
Note 1
VLED
4.8
5.0
5.2
V
Note 2
Current consumption
Icc