import { _ as _export_sfc, c as createElementBlock, o as openBlock, a8 as createStaticVNode } from "./chunks/framework.Clpp4x2N.js"; const __pageData = JSON.parse('{"title":"IS31FL3741 Driver","description":"","frontmatter":{},"headers":[],"relativePath":"drivers/is31fl3741.md","filePath":"drivers/is31fl3741.md"}'); const _sfc_main = { name: "drivers/is31fl3741.md" }; const _hoisted_1 = /* @__PURE__ */ createStaticVNode('

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.

IS31FL3741A Datasheet

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:

make
COMMON_VPATH += $(DRIVER_PATH)/led/issi\nSRC += is31fl3741-mono.c # For single-color\nSRC += is31fl3741.c # For RGB\nI2C_DRIVER_REQUIRED = yes

Basic Configuration ​

Add the following to your config.h:

DefineDefaultDescription
IS31FL3741_SDB_PINNot definedThe GPIO pin connected to the drivers' shutdown pins
IS31FL3741_I2C_TIMEOUT100The I²C timeout in milliseconds
IS31FL3741_I2C_PERSISTENCE0The number of times to retry I²C transmissions
IS31FL3741_I2C_ADDRESS_1Not definedThe I²C address of driver 0
IS31FL3741_I2C_ADDRESS_2Not definedThe I²C address of driver 1
IS31FL3741_I2C_ADDRESS_3Not definedThe I²C address of driver 2
IS31FL3741_I2C_ADDRESS_4Not definedThe I²C address of driver 3
IS31FL3741_CONFIGURATION1The value of the configuration register
IS31FL3741_PWM_FREQUENCYIS31FL3741_PWM_FREQUENCY_29K_HZThe PWM frequency of the LEDs (IS31FL3741A only)
IS31FL3741_SW_PULLUPIS31FL3741_PUR_32K_OHMThe SWx pullup resistor value
IS31FL3741_CS_PULLDOWNIS31FL3741_PDR_32K_OHMThe CSx pulldown resistor value
IS31FL3741_GLOBAL_CURRENT0xFFThe 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:

DefineValue
IS31FL3741_I2C_ADDRESS_GND0x30
IS31FL3741_I2C_ADDRESS_SCL0x31
IS31FL3741_I2C_ADDRESS_SDA0x32
IS31FL3741_I2C_ADDRESS_VCC0x33

PWM Frequency ​

The PWM frequency can be adjusted (for IS31FL3741A only) by adding the following to your config.h:

c
#define IS31FL3741_PWM_FREQUENCY IS31FL3741_PWM_FREQUENCY_29K_HZ

Valid values are:

DefineFrequency
IS31FL3741_PWM_FREQUENCY_29K_HZ29 kHz (default)
IS31FL3741_PWM_FREQUENCY_3K6_HZ3.6 kHz
IS31FL3741_PWM_FREQUENCY_1K8_HZ1.8 kHz
IS31FL3741_PWM_FREQUENCY_900_HZ900 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:

c
#define IS31FL3741_SW_PULLUP IS31FL3741_PUR_32K_OHM\n#define IS31FL3741_CS_PULLDOWN IS31FL3741_PDR_32K_OHM

Valid values for IS31FL3741_SW_PULLUP are:

DefineResistance
IS31FL3741_PUR_0_OHMNone
IS31FL3741_PUR_0K5_OHM0.5 kΩ
IS31FL3741_PUR_1K_OHM1 kΩ
IS31FL3741_PUR_2K_OHM2 kΩ
IS31FL3741_PUR_4K_OHM4 kΩ
IS31FL3741_PUR_8K_OHM8 kΩ
IS31FL3741_PUR_16K_OHM16 kΩ
IS31FL3741_PUR_32K_OHM32 kΩ (default)

Valid values for IS31FL3741_CS_PULLDOWN are:

DefineResistance
IS31FL3741_PDR_0_OHMNone
IS31FL3741_PDR_0K5_OHM0.5 kΩ
IS31FL3741_PDR_1K_OHM1 kΩ
IS31FL3741_PDR_2K_OHM2 kΩ
IS31FL3741_PDR_4K_OHM4 kΩ
IS31FL3741_PDR_8K_OHM8 kΩ
IS31FL3741_PDR_16K_OHM16 kΩ
IS31FL3741_PDR_32K_OHM32 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:

c
#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:

c
const is31fl3741_led_t PROGMEM g_is31fl3741_leds[IS31FL3741_LED_COUNT] = {\n/* Driver\n *   |  R         G         B */\n    {0, SW1_CS1,  SW1_CS2,  SW1_CS3},\n    // etc...\n};

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:

c
const is31fl3741_led_t PROGMEM g_is31fl3741_leds[IS31FL3741_LED_COUNT] = {\n/* Driver\n *   |  V */\n    {0, SW1_CS1},\n    // etc...\n};

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 ​

void is31fl3741_init(uint8_t index) ​

Initialize the LED driver. This function should be called first.

Arguments ​

void is31fl3741_write_register(uint8_t index, uint8_t reg, uint8_t data) ​

Set the value of the given register.

Arguments ​

void is31fl3741_select_page(uint8_t index, uint8_t page) ​

Change the current page for configuring the LED driver.

Arguments ​

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 ​

void is31fl3741_set_color_all(uint8_t red, uint8_t green, uint8_t blue) ​

Set the color of all LEDs (RGB driver only).

Arguments ​

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 ​

void is31fl3741_set_value_all(uint8_t value) ​

Set the brightness of all LEDs (single-color driver only).

Arguments ​

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 ​

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 ​

void is31fl3741_update_pwm_buffers(uint8_t index) ​

Flush the PWM values to the LED driver.

Arguments ​

void is31fl3741_update_led_control_registers(uint8_t index) ​

Flush the LED control register values to the LED driver.

Arguments ​

', 99); const _hoisted_100 = [ _hoisted_1 ]; function _sfc_render(_ctx, _cache, $props, $setup, $data, $options) { return openBlock(), createElementBlock("div", null, _hoisted_100); } const is31fl3741 = /* @__PURE__ */ _export_sfc(_sfc_main, [["render", _sfc_render]]); export { __pageData, is31fl3741 as default };