1 /* Copyright 2018 Jason Williams (Wilba)
3 * This program is free software: you can redistribute it and/or modify
4 * it under the terms of the GNU General Public License as published by
5 * the Free Software Foundation, either version 2 of the License, or
6 * (at your option) any later version.
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
13 * You should have received a copy of the GNU General Public License
14 * along with this program. If not, see <http://www.gnu.org/licenses/>.
16 #include "is31fl3218.h"
17 #include "i2c_master.h"
19 // This is the full 8-bit address
20 #define ISSI_ADDRESS 0b10101000
22 // These are the register addresses
23 #define ISSI_REG_SHUTDOWN 0x00
24 #define ISSI_REG_PWM 0x01
25 #define ISSI_REG_CONTROL 0x13
26 #define ISSI_REG_UPDATE 0x16
27 #define ISSI_REG_RESET 0x17
29 // Default timeout if no I2C response
30 #define ISSI_TIMEOUT 100
32 // Reusable buffer for transfers
33 uint8_t g_twi_transfer_buffer[20];
35 // IS31FL3218 has 18 PWM outputs and a fixed I2C address, so no chaining.
36 // If used as RGB LED driver, LEDs are assigned RGB,RGB,RGB,RGB,RGB,RGB
37 uint8_t g_pwm_buffer[18];
38 bool g_pwm_buffer_update_required = false;
40 void IS31FL3218_write_register(uint8_t reg, uint8_t data) {
41 g_twi_transfer_buffer[0] = reg;
42 g_twi_transfer_buffer[1] = data;
43 i2c_transmit(ISSI_ADDRESS, g_twi_transfer_buffer, 2, ISSI_TIMEOUT);
46 void IS31FL3218_write_pwm_buffer(uint8_t *pwm_buffer) {
47 g_twi_transfer_buffer[0] = ISSI_REG_PWM;
48 for (int i = 0; i < 18; i++) {
49 g_twi_transfer_buffer[1 + i] = pwm_buffer[i];
52 i2c_transmit(ISSI_ADDRESS, g_twi_transfer_buffer, 19, ISSI_TIMEOUT);
55 void IS31FL3218_init(void) {
56 // In case we ever want to reinitialize (?)
57 IS31FL3218_write_register(ISSI_REG_RESET, 0x00);
59 // Turn off software shutdown
60 IS31FL3218_write_register(ISSI_REG_SHUTDOWN, 0x01);
62 // Set all PWM values to zero
63 for (uint8_t i = 0; i < 18; i++) {
64 IS31FL3218_write_register(ISSI_REG_PWM + i, 0x00);
67 // Enable all channels
68 for (uint8_t i = 0; i < 3; i++) {
69 IS31FL3218_write_register(ISSI_REG_CONTROL + i, 0b00111111);
72 // Load PWM registers and LED Control register data
73 IS31FL3218_write_register(ISSI_REG_UPDATE, 0x01);
76 void IS31FL3218_set_color(int index, uint8_t red, uint8_t green, uint8_t blue) {
77 g_pwm_buffer[index * 3 + 0] = red;
78 g_pwm_buffer[index * 3 + 1] = green;
79 g_pwm_buffer[index * 3 + 2] = blue;
80 g_pwm_buffer_update_required = true;
83 void IS31FL3218_set_color_all(uint8_t red, uint8_t green, uint8_t blue) {
84 for (int i = 0; i < 6; i++) {
85 IS31FL3218_set_color(i, red, green, blue);
89 void IS31FL3218_update_pwm_buffers(void) {
90 if (g_pwm_buffer_update_required) {
91 IS31FL3218_write_pwm_buffer(g_pwm_buffer);
92 // Load PWM registers and LED Control register data
93 IS31FL3218_write_register(ISSI_REG_UPDATE, 0x01);
95 g_pwm_buffer_update_required = false;