11 KiB
IS31FL3741 Driver
I²C 39x9 LED matrix driver by Lumissil. Supports a maximum of four drivers, each controlling up to 351 single-color LEDs, or 117 RGB LEDs.
Usage
The IS31FL3741 driver code is automatically included if you are using the LED Matrix or RGB Matrix feature with the is31fl3741 driver set, and you would use those APIs instead.
However, if you need to use the driver standalone, add this to your rules.mk:
COMMON_VPATH += $(DRIVER_PATH)/led/issi
SRC += is31fl3741-mono.c # For single-color
SRC += is31fl3741.c # For RGB
I2C_DRIVER_REQUIRED = yes
Basic Configuration
Add the following to your config.h:
| Define | Default | Description |
|---|---|---|
IS31FL3741_SDB_PIN |
Not defined | The GPIO pin connected to the drivers' shutdown pins |
IS31FL3741_I2C_TIMEOUT |
100 |
The I²C timeout in milliseconds |
IS31FL3741_I2C_PERSISTENCE |
0 |
The number of times to retry I²C transmissions |
IS31FL3741_I2C_ADDRESS_1 |
Not defined | The I²C address of driver 0 |
IS31FL3741_I2C_ADDRESS_2 |
Not defined | The I²C address of driver 1 |
IS31FL3741_I2C_ADDRESS_3 |
Not defined | The I²C address of driver 2 |
IS31FL3741_I2C_ADDRESS_4 |
Not defined | The I²C address of driver 3 |
IS31FL3741_CONFIGURATION |
1 |
The value of the configuration register |
IS31FL3741_PWM_FREQUENCY |
IS31FL3741_PWM_FREQUENCY_29K_HZ |
The PWM frequency of the LEDs (IS31FL3741A only) |
IS31FL3741_SW_PULLUP |
IS31FL3741_PUR_32K_OHM |
The SWx pullup resistor value |
IS31FL3741_CS_PULLDOWN |
IS31FL3741_PDR_32K_OHM |
The CSx pulldown resistor value |
IS31FL3741_GLOBAL_CURRENT |
0xFF |
The global current control value |
I²C Addressing
The IS31FL3741 has four possible 7-bit I²C addresses, depending on how the ADDR pin is connected.
To configure this, set the IS31FL3741_I2C_ADDRESS_n defines to one of the following in your config.h, where n denotes the driver index:
| Define | Value |
|---|---|
IS31FL3741_I2C_ADDRESS_GND |
0x30 |
IS31FL3741_I2C_ADDRESS_SCL |
0x31 |
IS31FL3741_I2C_ADDRESS_SDA |
0x32 |
IS31FL3741_I2C_ADDRESS_VCC |
0x33 |
PWM Frequency
The PWM frequency can be adjusted (for IS31FL3741A only) by adding the following to your config.h:
#define IS31FL3741_PWM_FREQUENCY IS31FL3741_PWM_FREQUENCY_29K_HZ
Valid values are:
| Define | Frequency |
|---|---|
IS31FL3741_PWM_FREQUENCY_29K_HZ |
29 kHz (default) |
IS31FL3741_PWM_FREQUENCY_3K6_HZ |
3.6 kHz |
IS31FL3741_PWM_FREQUENCY_1K8_HZ |
1.8 kHz |
IS31FL3741_PWM_FREQUENCY_900_HZ |
900 Hz |
De-Ghosting
These settings control the pullup and pulldown resistor values on the CSx and SWy pins respectively, for the purposes of eliminating ghosting. Refer to the datasheet (p. 18) for more information on how and why this occurs.
To adjust the resistor values, add the following to your config.h:
#define IS31FL3741_SW_PULLUP IS31FL3741_PUR_32K_OHM
#define IS31FL3741_CS_PULLDOWN IS31FL3741_PDR_32K_OHM
Valid values for IS31FL3741_SW_PULLUP are:
| Define | Resistance |
|---|---|
IS31FL3741_PUR_0_OHM |
None |
IS31FL3741_PUR_0K5_OHM |
0.5 kΩ |
IS31FL3741_PUR_1K_OHM |
1 kΩ |
IS31FL3741_PUR_2K_OHM |
2 kΩ |
IS31FL3741_PUR_4K_OHM |
4 kΩ |
IS31FL3741_PUR_8K_OHM |
8 kΩ |
IS31FL3741_PUR_16K_OHM |
16 kΩ |
IS31FL3741_PUR_32K_OHM |
32 kΩ (default) |
Valid values for IS31FL3741_CS_PULLDOWN are:
| Define | Resistance |
|---|---|
IS31FL3741_PDR_0_OHM |
None |
IS31FL3741_PDR_0K5_OHM |
0.5 kΩ |
IS31FL3741_PDR_1K_OHM |
1 kΩ |
IS31FL3741_PDR_2K_OHM |
2 kΩ |
IS31FL3741_PDR_4K_OHM |
4 kΩ |
IS31FL3741_PDR_8K_OHM |
8 kΩ |
IS31FL3741_PDR_16K_OHM |
16 kΩ |
IS31FL3741_PDR_32K_OHM |
32 kΩ (default) |
Global Current Control
This setting controls the current sunk by the CSx pins, from 0 to 255. By default, the value is the maximum (255), but if you need to lower it, add the following to your config.h:
#define IS31FL3741_GLOBAL_CURRENT 0xFF
ARM/ChibiOS Configuration
Depending on the ChibiOS board configuration, you may need to enable and configure I²C at the keyboard level.
LED Mapping
In order to use this driver, each output must be mapped to an LED index, by adding the following to your <keyboardname>.c:
const is31fl3741_led_t PROGMEM g_is31fl3741_leds[IS31FL3741_LED_COUNT] = {
/* Driver
* | R G B */
{0, SW1_CS1, SW1_CS2, SW1_CS3},
// etc...
};
In this example, the red, green and blue channels for the first LED index on driver 0 all have their anodes connected to the SW1 pin, and their cathodes on the CS1, CS2 and CS3 pins respectively.
For the single-color driver, the principle is the same, but there is only one channel:
const is31fl3741_led_t PROGMEM g_is31fl3741_leds[IS31FL3741_LED_COUNT] = {
/* Driver
* | V */
{0, SW1_CS1},
// etc...
};
These values correspond to the register indices as shown in the datasheet on page 12, figure 8.
API
struct is31fl3741_led_t
Contains the PWM register addresses for a single RGB LED.
Members
uint32_t driver
The driver index of the LED, from 0 to 3.uint32_t r
The output PWM register address for the LED's red channel (RGB driver only).uint32_t g
The output PWM register address for the LED's green channel (RGB driver only).uint32_t b
The output PWM register address for the LED's blue channel (RGB driver only).uint32_t v
The output PWM register address for the LED (single-color driver only).
void is31fl3741_init(uint8_t index)
Initialize the LED driver. This function should be called first.
Arguments
uint8_t index
The driver index.
void is31fl3741_write_register(uint8_t index, uint8_t reg, uint8_t data)
Set the value of the given register.
Arguments
uint8_t index
The driver index.uint8_t reg
The register address.uint8_t data
The value to set.
void is31fl3741_select_page(uint8_t index, uint8_t page)
Change the current page for configuring the LED driver.
Arguments
uint8_t index
The driver index.uint8_t page
The page number to select.
void is31fl3741_set_color(int index, uint8_t red, uint8_t green, uint8_t blue)
Set the color of a single LED (RGB driver only). This function does not immediately update the LEDs; call is31fl3741_update_pwm_buffers() after you are finished.
Arguments
int index
The LED index (ie. the index into theg_is31fl3741_ledsarray).uint8_t red
The red value to set.uint8_t green
The green value to set.uint8_t blue
The blue value to set.
void is31fl3741_set_color_all(uint8_t red, uint8_t green, uint8_t blue)
Set the color of all LEDs (RGB driver only).
Arguments
uint8_t red
The red value to set.uint8_t green
The green value to set.uint8_t blue
The blue value to set.
void is31fl3741_set_value(int index, uint8_t value)
Set the brightness of a single LED (single-color driver only). This function does not immediately update the LEDs; call is31fl3741_update_pwm_buffers() after you are finished.
Arguments
int index
The LED index (ie. the index into theg_is31fl3741_ledsarray).uint8_t value
The brightness value to set.
void is31fl3741_set_value_all(uint8_t value)
Set the brightness of all LEDs (single-color driver only).
Arguments
uint8_t value
The brightness value to set.
void is31fl3741_set_led_control_register(uint8_t index, bool red, bool green, bool blue)
Configure the LED control registers for a single LED (RGB driver only). This function does not immediately update the LEDs; call is31fl3741_update_led_control_registers() after you are finished.
Arguments
uint8_t index
The LED index (ie. the index into theg_is31fl3741_ledsarray).bool red
Enable or disable the red channel.bool green
Enable or disable the green channel.bool blue
Enable or disable the blue channel.
void is31fl3741_set_led_control_register(uint8_t index, bool value)
Configure the LED control registers for a single LED (single-color driver only). This function does not immediately update the LEDs; call is31fl3741_update_led_control_registers() after you are finished.
Arguments
uint8_t index
The LED index (ie. the index into theg_is31fl3741_ledsarray).bool value
Enable or disable the LED.
void is31fl3741_update_pwm_buffers(uint8_t index)
Flush the PWM values to the LED driver.
Arguments
uint8_t index
The driver index.
void is31fl3741_update_led_control_registers(uint8_t index)
Flush the LED control register values to the LED driver.
Arguments
uint8_t index
The driver index.