SN32F2XX Driver

This driver provides support for PWM driven RGB LED matrix on the Sonix SN32F2xx series of chips.

Hardware Configuration

The most common way to configure the LED wiring is on a 3 ( R/B/G channel sinks) x 1 ( actively driven PWM line) matrix, controlled by transistors through GPIO pins.

    Default configuration example

    COLS key / led
    SS8050 transistors NPN driven low
    base      - GPIO
    collector - LED Col pins
    emitter   - VDD

    VDD     GPIO
    (E)     (B)
     |  PNP  |
     |_______|
         |
         |
        (C)
        LED

    ROWS RGB
    SS8550 transistors PNP driven high
    base      - GPIO
    collector - LED RGB row pins
    emitter   - GND

        LED
        (C)
         |
         |
      _______
     |  NPN  |
     |       |
    (B)     (E)
    GPIO    GND

The driver has provisions to either use hardware PWM, or bitbang if the pins configured do not have available PWM mode.

Usage

In most cases, the SN32F2XX driver code is automatically included if you are using the RGB Matrix feature with the sn32f2xx driver set, and you would use that API instead.

However, if you need to use the driver standalone, add the following to your rules.mk:

COMMON_VPATH += $(DRIVER_PATH)/led
SRC += sn32f2xx.c

You can then call the SN32F2XX API by including sn32f2xx.h in your code.

Basic Configuration

Add the following to your config.h:

Define	Default	Description
SN32F2XX_RGB_MATRIX_ROW_PINS	Not defined	The GPIO pins connected to the RGB sink triplets on every row of the LEDs in the matrix1
SN32F2XX_RGB_MATRIX_COL_PINS	MATRIX_COL_PINS	The GPIO pins connected to the LED columns on every column of the LEDs in the matrix2
SN32F2XX_RGB_MATRIX_COLS	MATRIX_COLS	Number of LED columns in the LED matrix
SN32F2XX_RGB_MATRIX_ROWS	MATRIX_ROWS	Number of LED rows in the LED matrix
SN32F2XX_RGB_MATRIX_ROW_CHANNELS	3	The number of available color channels for each LED
SN32F2XX_PWM_OUTPUT_ACTIVE_LEVEL	SN32F2XX_PWM_OUTPUT_ACTIVE_LOW	The logic level that enables PWM output. Depends on transistor controlling PWM
SN32F2XX_RGB_OUTPUT_ACTIVE_LEVEL	SN32F2XX_RGB_OUTPUT_ACTIVE_HIGH	The logic level that enables RGB output. Depends on transistor controlling RGB sinks
SN32F2XX_PWM_DIRECTION	DIODE_DIRECTION	The scanning logic direction for the LED matrix
SN32F2XX_PWM_CONTROL	HARDWARE_PWM	Toggles hardware or software control for the PWM
SN32F2XX_LED_OUTPUT_LUMINOSITY_R	1	Luminosity correction factor for the Red channel
SN32F2XX_LED_OUTPUT_LUMINOSITY_G	1	Luminosity correction factor for the Green channel
SN32F2XX_LED_OUTPUT_LUMINOSITY_B	1	Luminosity correction factor for the Blue channel

Notes:

1. The currently supported RGB byte order is R/B/G for each row triplet. Example config for 3 rows (R0, B0, G0, R1, B1, G1, R2, B2, G2)
2. If not user defined, it assumes shared matrix

Shared Matrix

The driver can share LED matrix wiring with the key matrix, specifically columns. It takes over the key scanning routines and carefully times it to avoid key chatter and LED artifacts. Please note that key scan cycles are affected, although the result is a snappy key scan.

ChibiOS/ARM Configuration

The following defines apply only to ARM devices:

PWM Driver

Depending on the ChibiOS board configuration, you may need to enable PWM at the keyboard level. For SN32, this would look like:

halconf.h:

#define HAL_USE_PWM TRUE

mcuconf.h:

#undef SN32_PWM_USE_CT16B1
#define SN32_PWM_USE_CT16B1 TRUE

and additionally configure the CT peripheral

mcuconf.h:

#undef SN32_PWM_NO_RESET
#define SN32_PWM_NO_RESET TRUE

The driver uses the CT timer to handle PWM, even if software PWM is selected.

API

void sn32f2xx_set_color(int index, uint8_t red, uint8_t green, uint8_t blue)

Set the color of a single LED (RGB driver only).

Arguments

• int index The LED index.
• 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 sn32f2xx_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.