ST X-NUCLEO-LED12A1 User manual

Introduction
The X-NUCLEO-LED12A1 LED driver expansion board for STM32 Nucleo features four LED1202 devices that can drive up to
48 LEDs.
The LED1202 is a 12-channel low quiescent current LED driver, which guarantees 5 V output driving capability. Each channel is
able to provide up to 20 mA with a headroom voltage of 350 mV (typ.) only.
The output current can be adjusted separately for each channel through an 8-bit analog and 12-bit digital dimming control.
The X-NUCLEO-LED12A1 expansion board comes with an additional LED panel board that houses two LEDs matrices: a 6x8
white LED matrix and a 4x4 RGB matrix.
LED matrices can be supplied via an external power supply connected to J13 connector and by selecting the right path through
J15 jumper to reach the maximum luminosity available.
Figure 1. X-NUCLEO-LED12A1 expansion board
Figure 2. LED panel board
Getting started with the X-NUCLEO-LED12A1 LED driver expansion board based
on LED1202 for STM32 Nucleo
UM2879
User manual
UM2879 - Rev 2 - November 2021
For further information contact your local STMicroelectronics sales office.
www.st.com

1Getting started
1.1 Overview
The X-NUCLEO-LED12A1 expansion board features:
•Four LED1202 devices driving up to 48 LEDs
• One double row pin array connector for external LED panel connection
• One jumper selector for internal/external LED power supply
• One panel with 48 white LEDs/16 RGB LEDs included
• Arduino UNO R3 connectors
• Free comprehensive development firmware library compatible with STM32Cube
• Scalable solution for multiple board stack
• RoHS and WEEE compliant
1.2 Hardware requirements
The X-NUCLEO-LED12A1 expansion board is designed to be used with any STM32 Nucleo development
board, although complete testing has been performed using the NUCLEO-L073RZ hosting the STM32L073RZ
microcontroller.
1.3 System requirements
To use STM32 Nucleo development boards with the X-NUCLEO-LED12A1 expansion board, the following
software and hardware are required:
• an STM32 Nucleo-64 development board
• a Windows® PC to install the firmware package
• a USB type A to Mini-B USB cable to connect the STM32 Nucleo board to the PC
• 128 MB of RAM and 40 MB of free hard disk space to install the firmware package (order code: X-CUBE-
LED12A1)
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Getting started
UM2879 - Rev 2 page 2/17

2Connectors
The X-NUCLEO-LED12A1 expansion board allows the user to test the functionality of the LED1202, together with
the use of the additional LED panel board.
The 4 LED1202 ICs and the STM32 Nucleo development board are connected through CN5, CN6, CN8 and CN9
connectors (see the tables below).
Table 1. Interconnections between X-NUCLEO-LED12A1 expansion board and NUCLEO-L073RZ
development board (left side)
Signal Connector Pin number NUCLEO-L073RZ X-NUCLEO-LED12A1
NC
CN6 Power
1 - -
IOREF 2 - (NC)
RESET 3 - -
3V3 4 - 3V3
5V 5 - 5V (VDD)
GND 6 - GND
GND 7 - GND
VIN 8 - -
A0
CN8 Power
1 PA0 IRQ_MCU (alt.)
A1 2 PA1 IRQ_MCU (alt.)
A2 3 PA4 IRQ_MCU (alt.)
A3 4 PB0 IRQ_MCU (alt.)
A4 5 PC1 NC
A5 6 PC0 NC
Table 2. Interconnections between X-NUCLEO-LED12A1 expansion board and NUCLEO-L073RZ
development board (right side)
Signal Connector Pin number NUCLEO-L073RZ X-NUCLEO-LED12A1
D15
CN5 Digital
10 PB8 SCL_MCU
D14 9 PB9 SDA_MCU
AVDD 8 AVDD NC
GND 7 GND NC
D13 6 PA5 NC
D12 5 PA6 NC
D11 4 PA7 NC
D10 3 PB6 NC
D9 2 PC7 NC
D8 1 PA9 NC
D7
CN9 Digital
8 PA8 NC
D6 7 PB10 NC
D5 6 PB4 NC
D4 5 PB5 NC
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Connectors
UM2879 - Rev 2 page 3/17

Signal Connector Pin number NUCLEO-L073RZ X-NUCLEO-LED12A1
D3
CN9 Digital
4 PB3 IRQ_MCU
D2 3 PA10 NC
D1 2 PA2 NC
D0 1 PA3 NC
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Connectors
UM2879 - Rev 2 page 4/17

3Host interface and GPIO connection
The X-NUCLEO-LED12A1 expansion board embeds four LED1202 devices and is powered by the STM32 Nucleo
development board.
The devices are driven by the microcontroller via I2C interface, connected through the same I2C bus and
synchronized by a clock chain.
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Host interface and GPIO connection
UM2879 - Rev 2 page 5/17

4Components
Figure 3. X-NUCLEO-LED12A1 expansion board component placement
1. LED1202
2. LED1202
3. LED1202
4. LED1202
5. LED panel connector
6. LED panel power supply connector
12
3
4
56
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Components
UM2879 - Rev 2 page 6/17

5LED1202
The LED1202 is a 12-channel low quiescent current LED driver which guarantees 5 V output driving capability.
Each channel is able to provide up to 20 mA with a headroom voltage of 350 mV (typ.) only. The output current
can be adjusted separately for each channel by an 8-bit analog and 12-bit digital dimming control.
A slow turn-on and turn-off time improves the system low noise generation performance; moreover, the phase
shifting function helps to reduce the inrush current. Eight patterns can be stored in the internal registers for
automatic sequencing without involving the MCU.
The pattern sequence can be also configured for duration time and number of repetitions. In multi-device
applications, a common clock domain can be shared for timing synchronization.
The device features thermal shutdown and open LED detection. The device I²C interface is based on fast mode
specification and works up to 400 kHz. Eight I²C addresses are possible by using two configuration pins (A0/A1)
only.
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LED1202
UM2879 - Rev 2 page 7/17

6Board setup
To test the expansion board follow the procedure below.
Step 1. Connect the X-NUCLEO-LED12A1 expansion board to the STM32 Nucleo development board from the
top through the Arduino UNO R3 connectors.
Step 2. Power the STM32 Nucleo development board using a mini-B USB cable.
Step 3. Program the firmware on the STM32 Nucleo development board using the provided example.
Step 4. Reset the MCU using the STM32 Nucleo reset button.
Step 5. Configure J15 jumper for internal or external LED power supply.
– Connect pin 1 with pin 2 for external LED power supply.
– Connect pin 2 with pin 3 for internal LED power supply.
For internal LED power supply, the PC USB port drives the LED current.
Important:
For external LED power supply, the current capability has to be provided through J13 connector. Do not apply an external
voltage greater than 6 V: as this is the absolute maximum rating of LED1202 LED channels, it is recommended to remain
below 5.5 V.
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Board setup
UM2879 - Rev 2 page 8/17

7Schematic diagrams
Figure 4. X-NUCLEO-LED12A1 expansion board circuit schematic
LED CONNECTORS
NUCLEO MORPHO CONNECTORS
ADDR=58h
ADDR=5Ah
ADDR=59h
Place close to J13
ADDR=5Bh
ARDUINO
CONNECTORS
U2
LED1202
IRQn
1
CS0
2
CS1
3
CS2
4
CS3
5
CS4
6
CS5
7
GND
8
CS6
9
CS7
10
VIN 15
CS11 14
CS10 13
CS9 12
CS8 11
SCL 20
SDA 19
A1 18 A0 17
VLDO 16
R4
10K
CN9
CONN1x8 2.54mm
1
2
3
4
5
6
7
8
C12
1u 16V
C15
1u 16V
J13
Phoenix 1725656
1
2
R1
0R
C13
1u 16V
R16 NM R6
10K
U4
LED1202
IRQn
1
CS0
2
CS1
3
CS2
4
CS3
5
CS4
6
CS5
7
GND
8
CS6
9
CS7
10
VIN 15
CS11 14
CS10 13
CS9 12
CS8 11
SCL 20
SDA 19
A1 18 A0 17
VLDO 16
+ C11
180u 16V
C4
1u 16V
R12
10K
R15 NM
R18 NM
C6
1u 16V
R1336K
J15
HEADERx3 2.54
1
2
3
U5
LDL112PT-TR
VOUT 2
GND
3
VIN
4
EN
5ADJ 1
CN6
CONN1x8 2.54mm
1
2
3
4
5
6
7
8
C14
1u 16V
J18
CONN PLUG 26x2 1.27mm Right Angle
1
3
5
7
9
11
13
15
17
19
21
23
25
27
29
31
33
35
37
39
41
43
45
47
49
2
4
6
8
10
12
14
16
18
20
22
24
26
28
30
32
34
36
38
40
42
44
46
48
50
CN7
CONN19x2 2.54 Low Insertion Force
1
3
5
7
9
11
13
15
17
19
21
23
25
27
29
31
33
35
37
2
4
6
8
10
12
14
16
18
20
22
24
26
28
30
32
34
36
38
R5
10K
R7
10K
CN5
CONN1x10 2.54mm
1
2
3
4
5
6
7
8
9
10
R17 NM
C3
1u 16V
C2
1u 16V
R3
10K
CN10
CONN19x2 2.54 Low Insertion Force
1
3
5
7
9
11
13
15
17
19
21
23
25
27
29
31
33
35
37
2
4
6
8
10
12
14
16
18
20
22
24
26
28
30
32
34
36
38
U3
LED1202
IRQn
1
CS0
2
CS1
3
CS2
4
CS3
5
CS4
6
CS5
7
GND
8
CS6
9
CS7
10
VIN 15
CS11 14
CS10 13
CS9 12
CS8 11
SCL 20
SDA 19
A1 18 A0 17
VLDO 16
C10
22u 16V
R2
10K
CN8
CONN1x6 2.54mm
1
2
3
4
5
6
R11
0R
R14
10K
C1
1u 16V
U1
LED1202
IRQn
1
CS0
2
CS1
3
CS2
4
CS3
5
CS4
6
CS5
7
GND
8
CS6
9
CS7
10
VIN 15
CS11 14
CS10 13
CS9 12
CS8 11
SCL 20
SDA 19
A1 18 A0 17
VLDO 16
C5
1u 16V
3V3
L1_CS0
L1_CS1
L1_CS2
L1_CS3
L1_CS4
SCL
SDA
L1_CS5
SCL
SDA
L1_CS6
L1_CS7
L1_CS8
L1_CS9
L1_CS10
L1_CS11
LED_IRQ 3V3 LED_IRQ 3V3
L3_CS0 L3_CS11 L1_CS0 L1_CS11
L3_CS1 L3_CS10 L1_CS1 L1_CS10
L3_CS2 L3_CS9 L1_CS2 L1_CS9
L3_CS3 L3_CS8 L1_CS3 L1_CS8
L3_CS0
L3_CS1
L3_CS2
L3_CS3
L3_CS4
L3_CS4 L3_CS5
GND
L3_CS6 L3_CS7 L1_CS4 L1_CS5
GND
L1_CS6 L1_CS7
L3_CS5
L3_CS6
SCL
SDA
SCL
SDA
LED_IRQ 3V3
L2_CS0 L2_CS11
L2_CS1 L2_CS10
L2_CS2 L2_CS9
L2_CS3 L2_CS8
L2_CS4 L2_CS5
GND
L2_CS6 L2_CS7
3V3
3V3
SDA SCL
LED_IRQ
VLED
3V7
3V3
SCL
SDA
LED_IRQ 3V3
L4_CS0 L4_CS11
L4_CS1 L4_CS10
L4_CS2 L4_CS9
L4_CS3 L4_CS8
L4_CS4 L4_CS5
GND
L4_CS6 L4_CS7
L3_CS11
L3_CS10
L3_CS9
L3_CS8
L3_CS7
L4_CS0
L4_CS1
L4_CS2
L4_CS3
L4_CS4
L4_CS5
L4_CS6
L4_CS7
L4_CS8
L4_CS9
L4_CS10
L4_CS11
L2_CS11
L2_CS10
L2_CS9
L2_CS8
L2_CS7
L2_CS6
L2_CS5
L2_CS4
L2_CS3
L2_CS2
L2_CS1
L2_CS0
5V
5V 3V7
3V3
3V3
5V
VLED
LED_IRQ
I_3
I_2
I_5
I_4 I_1I_2
I_3
I_4
I_5
I_2
I_3
I_4
I_5
I_1
SCL
SDA
I_1
UM2879 - Rev 2 page 9/17
UM2879
Schematic diagrams

Figure 5. LED panel circuit schematic
UM2879 - Rev 2 page 10/17
UM2879
Schematic diagrams