import { _ as _export_sfc, c as createElementBlock, o as openBlock, a8 as createStaticVNode } from "./chunks/framework.B9AX-CPi.js"; const __pageData = JSON.parse('{"title":"IS31FL3745 Driver","description":"","frontmatter":{},"headers":[],"relativePath":"drivers/is31fl3745.md","filePath":"drivers/is31fl3745.md"}'); const _sfc_main = { name: "drivers/is31fl3745.md" }; const _hoisted_1 = /* @__PURE__ */ createStaticVNode('

IS31FL3745 Driver ​

I²C 18x8 LED matrix driver by Lumissil. Supports a maximum of four drivers, each controlling up to 144 single-color LEDs, or 48 RGB LEDs.

IS31FL3745 Datasheet

Usage ​

The IS31FL3745 driver code is automatically included if you are using the LED Matrix or RGB Matrix feature with the is31fl3745 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 += is31fl3745-mono.c # For single-color\nSRC += is31fl3745.c # For RGB\nI2C_DRIVER_REQUIRED = yes

Basic Configuration ​

Add the following to your config.h:

DefineDefaultDescription
IS31FL3745_SDB_PINNot definedThe GPIO pin connected to the drivers' shutdown pins
IS31FL3745_I2C_TIMEOUT100The I²C timeout in milliseconds
IS31FL3745_I2C_PERSISTENCE0The number of times to retry I²C transmissions
IS31FL3745_I2C_ADDRESS_1Not definedThe I²C address of driver 0
IS31FL3745_I2C_ADDRESS_2Not definedThe I²C address of driver 1
IS31FL3745_I2C_ADDRESS_3Not definedThe I²C address of driver 2
IS31FL3745_I2C_ADDRESS_4Not definedThe I²C address of driver 3
IS31FL3745_SYNC_1IS31FL3745_SYNC_NONEThe sync configuration for driver 0
IS31FL3745_SYNC_2IS31FL3745_SYNC_NONEThe sync configuration for driver 1
IS31FL3745_SYNC_3IS31FL3745_SYNC_NONEThe sync configuration for driver 2
IS31FL3745_SYNC_4IS31FL3745_SYNC_NONEThe sync configuration for driver 3
IS31FL3745_CONFIGURATION0x31The value of the configuration register
IS31FL3745_SW_PULLDOWNIS31FL3745_PDR_2K_OHM_SW_OFFThe SWx pulldown resistor value
IS31FL3745_CS_PULLUPIS31FL3745_PUR_2K_OHM_CS_OFFThe CSx pullup resistor value
IS31FL3745_GLOBAL_CURRENT0xFFThe global current control value

I²C Addressing ​

The IS31FL3745 has 16 possible 7-bit I²C addresses, depending on how the ADDR1 and ADDR2 pins are connected.

To configure this, set the IS31FL3745_I2C_ADDRESS_n defines to one of the following in your config.h, where n denotes the driver index:

DefineValue
IS31FL3745_I2C_ADDRESS_GND_GND0x20
IS31FL3745_I2C_ADDRESS_GND_SCL0x21
IS31FL3745_I2C_ADDRESS_GND_SDA0x22
IS31FL3745_I2C_ADDRESS_GND_VCC0x23
IS31FL3745_I2C_ADDRESS_SCL_GND0x24
IS31FL3745_I2C_ADDRESS_SCL_SCL0x25
IS31FL3745_I2C_ADDRESS_SCL_SDA0x26
IS31FL3745_I2C_ADDRESS_SCL_VCC0x27
IS31FL3745_I2C_ADDRESS_SDA_GND0x28
IS31FL3745_I2C_ADDRESS_SDA_SCL0x29
IS31FL3745_I2C_ADDRESS_SDA_SDA0x2A
IS31FL3745_I2C_ADDRESS_SDA_VCC0x2B
IS31FL3745_I2C_ADDRESS_VCC_GND0x2C
IS31FL3745_I2C_ADDRESS_VCC_SCL0x2D
IS31FL3745_I2C_ADDRESS_VCC_SDA0x2E
IS31FL3745_I2C_ADDRESS_VCC_VCC0x2F

Multi-Driver Synchronization ​

Multiple IS31FL3745 drivers can be synchronized by connecting the SYNC pins together. One driver must be designated as the "master", and the others configured as "slave".

To do this, set the IS31FL3745_SYNC_n defines accordingly in your config.h, where n denotes the driver index:

DefineValue
IS31FL3745_SYNC_NONENo synchronization
IS31FL3745_SYNC_MASTERDriver configured as master
IS31FL3745_SYNC_SLAVEDriver configured as slave

De-Ghosting ​

These settings control the pulldown and pullup resistor values on the SWy and CSx pins respectively, for the purposes of eliminating ghosting. Refer to the datasheet (p. 23) for more information on how and why this occurs.

To adjust the resistor values, add the following to your config.h:

c
#define IS31FL3745_SW_PULLDOWN IS31FL3745_PDR_2K_OHM_SW_OFF\n#define IS31FL3745_CS_PULLUP IS31FL3745_PUR_2K_OHM_CS_OFF

Valid values for IS31FL3745_SW_PULLDOWN are:

DefineResistance
IS31FL3745_PDR_0_OHMNone (default)
IS31FL3745_PDR_0K5_OHM_SW_OFF0.5 kΩ in SWx off time
IS31FL3745_PDR_1K_OHM_SW_OFF1 kΩ in SWx off time
IS31FL3745_PDR_2K_OHM_SW_OFF2 kΩ in SWx off time (default)
IS31FL3745_PDR_1K_OHM1 kΩ
IS31FL3745_PDR_2K_OHM2 kΩ
IS31FL3745_PDR_4K_OHM4 kΩ
IS31FL3745_PDR_8K_OHM8 kΩ

Valid values for IS31FL3745_CS_PULLUP are:

DefineResistance
IS31FL3745_PUR_0_OHMNone (default)
IS31FL3745_PUR_0K5_OHM_CS_OFF0.5 kΩ in CSy off time
IS31FL3745_PUR_1K_OHM_CS_OFF1 kΩ in CSy off time
IS31FL3745_PUR_2K_OHM_CS_OFF2 kΩ in CSy off time (default)
IS31FL3745_PUR_1K_OHM1 kΩ
IS31FL3745_PUR_2K_OHM2 kΩ
IS31FL3745_PUR_4K_OHM4 kΩ
IS31FL3745_PUR_8K_OHM8 kΩ

Global Current Control ​

This setting controls the current sunk by the CSy 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 IS31FL3745_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 is31fl3745_led_t PROGMEM g_is31fl3745_leds[IS31FL3745_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 is31fl3745_led_t PROGMEM g_is31fl3745_leds[IS31FL3745_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 9.

API ​

struct is31fl3745_led_t ​

Contains the PWM register addresses for a single RGB LED.

Members ​

void is31fl3745_init(uint8_t index) ​

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

Arguments ​

void is31fl3745_write_register(uint8_t index, uint8_t reg, uint8_t data) ​

Set the value of the given register.

Arguments ​

void is31fl3745_select_page(uint8_t index, uint8_t page) ​

Change the current page for configuring the LED driver.

Arguments ​

void is31fl3745_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 is31fl3745_update_pwm_buffers() after you are finished.

Arguments ​

void is31fl3745_set_color_all(uint8_t red, uint8_t green, uint8_t blue) ​

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

Arguments ​

void is31fl3745_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 is31fl3745_update_pwm_buffers() after you are finished.

Arguments ​

void is31fl3745_set_value_all(uint8_t value) ​

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

Arguments ​

void is31fl3745_set_scaling_register(uint8_t index, uint8_t red, uint8_t green, uint8_t blue) ​

Configure the scaling registers for a single LED (RGB driver only). This function does not immediately update the LEDs; call is31fl3745_update_scaling_registers() after you are finished.

Arguments ​

void is31fl3745_set_scaling_register(uint8_t index, uint8_t value) ​

Configure the scaling register for a single LED (single-color driver only). This function does not immediately update the LEDs; call is31fl3745_update_scaling_registers() after you are finished.

Arguments ​

void is31fl3745_update_pwm_buffers(uint8_t index) ​

Flush the PWM values to the LED driver.

Arguments ​

void is31fl3745_update_scaling_registers(uint8_t index) ​

Flush the scaling register values to the LED driver.

Arguments ​

', 98); const _hoisted_99 = [ _hoisted_1 ]; function _sfc_render(_ctx, _cache, $props, $setup, $data, $options) { return openBlock(), createElementBlock("div", null, _hoisted_99); } const is31fl3745 = /* @__PURE__ */ _export_sfc(_sfc_main, [["render", _sfc_render]]); export { __pageData, is31fl3745 as default };