/* * Copyright (C) 2016 Inria * * This file is subject to the terms and conditions of the GNU Lesser * General Public License v2.1. See the file LICENSE in the top level * directory for more details. */ /** * @ingroup drivers_tsl2561 * @{ * * @file * @brief Device driver implementation for the TSL2561 Luminosity sensor. * * @author Alexandre Abadie * * @} */ #include #include #include "log.h" #include "tsl2561.h" #include "tsl2561_internals.h" #include "periph/i2c.h" #include "xtimer.h" #define ENABLE_DEBUG (0) #include "debug.h" /* internal helpers */ static void _enable(const tsl2561_t *dev); static void _disable(const tsl2561_t *dev); static void _read_data(const tsl2561_t *dev, uint16_t *full, uint16_t *ir); static void _print_init_info(const tsl2561_t *dev); /*---------------------------------------------------------------------------* * TSL2561 Core API * *---------------------------------------------------------------------------*/ int tsl2561_init(tsl2561_t *dev, i2c_t i2c, uint8_t addr, uint8_t gain, uint8_t integration) { dev->i2c_dev = i2c; dev->addr = addr; dev->gain = gain; dev->integration = integration; _print_init_info(dev); /* Initialize I2C interface */ if (i2c_init_master(dev->i2c_dev, I2C_SPEED_NORMAL)) { DEBUG("[Error] I2C device not enabled\n"); return TSL2561_NOI2C; } DEBUG("[Info] I2C device initialized with success!\n"); /* Acquire exclusive access */ i2c_acquire(dev->i2c_dev); DEBUG("[Info] Access acquired !\n"); /* Verify sensor ID */ uint8_t id; i2c_read_reg(dev->i2c_dev, dev->addr, TSL2561_COMMAND_MODE | TSL2561_REGISTER_ID, &id); DEBUG("[Info] ID ? %d\n", id); if (id != TSL2561_ID ) { DEBUG("[Error] not a TSL2561 sensor\n"); return TSL2561_BADDEV; } _enable(dev); /* configuring gain and integration time */ i2c_write_reg(dev->i2c_dev, dev->addr, TSL2561_COMMAND_MODE | TSL2561_REGISTER_TIMING, dev->integration | dev->gain); #if ENABLE_DEBUG uint8_t timing; i2c_read_reg(dev->i2c_dev, dev->addr, TSL2561_COMMAND_MODE | TSL2561_REGISTER_TIMING, &timing); DEBUG("[Info] Timing ? %d (expected: %d)\n", timing, dev->integration | dev->gain); #endif _disable(dev); return TSL2561_OK; } uint16_t tsl2561_read_illuminance(const tsl2561_t *dev) { /* Read IR and full spectrum values */ uint16_t ir = 0; uint16_t full = 0; _read_data(dev, &full, &ir); DEBUG("[Info] Full spectrum value: %i\n", (int)full); DEBUG("[Info] IR spectrum value: %i\n", (int)ir); /* Compute illuminance */ uint32_t channel_scale; uint32_t channel_1; uint32_t channel_0; switch (dev->integration) { case TSL2561_INTEGRATIONTIME_13MS: channel_scale = TSL2561_CHSCALE_TINT0; break; case TSL2561_INTEGRATIONTIME_101MS: channel_scale = TSL2561_CHSCALE_TINT1; break; default: /* No scaling ... integration time = 402ms */ channel_scale = (1 << TSL2561_CHSCALE); break; } /* Scale for gain (1x or 16x) */ if (!dev->gain) { channel_scale = channel_scale << 4; } /* scale the channel values */ channel_0 = (full * channel_scale) >> TSL2561_CHSCALE; channel_1 = (ir * channel_scale) >> TSL2561_CHSCALE; /* find the ratio of the channel values (Channel1/Channel0) */ uint32_t ratio_1 = 0; if (channel_0 != 0) { ratio_1 = (channel_1 << (TSL2561_RATIOSCALE + 1)) / channel_0; } /* round the ratio value */ uint32_t ratio = (ratio_1 + 1) >> 1; uint32_t b, m; if (ratio <= TSL2561_K1T) { b = TSL2561_B1T; m = TSL2561_M1T; } else if (ratio <= TSL2561_K2T) { b = TSL2561_B2T; m = TSL2561_M2T; } else if (ratio <= TSL2561_K3T) { b = TSL2561_B3T; m = TSL2561_M3T; } else if (ratio <= TSL2561_K4T) { b = TSL2561_B4T; m = TSL2561_M4T; } else if (ratio <= TSL2561_K5T) { b = TSL2561_B5T; m = TSL2561_M5T; } else if (ratio <= TSL2561_K6T) { b = TSL2561_B6T; m = TSL2561_M6T; } else if (ratio <= TSL2561_K7T) { b = TSL2561_B7T; m = TSL2561_M7T; } else { b = TSL2561_B8T; m = TSL2561_M8T; } uint32_t illuminance; illuminance = ((channel_0 * b) - (channel_1 * m)); /* round lsb (2^(TSL2561_SCALE - 1)) */ illuminance += (1 << (TSL2561_LUXSCALE - 1)); /* return strip off fractional portion */ return (uint16_t)(illuminance >> TSL2561_LUXSCALE); } static void _enable(const tsl2561_t *dev) { /* enabling device */ i2c_write_reg(dev->i2c_dev, dev->addr, TSL2561_COMMAND_MODE | TSL2561_REGISTER_CONTROL, TSL2561_CONTROL_POWERON); #if ENABLE_DEBUG uint8_t en; i2c_read_reg(dev->i2c_dev, dev->addr, TSL2561_COMMAND_MODE | TSL2561_REGISTER_CONTROL, &en); DEBUG("[Info] Enabled ? %s\n", en == 3 ? "true" : "false"); #endif } static void _disable(const tsl2561_t *dev) { /* disabling device */ i2c_write_reg(dev->i2c_dev, dev->addr, TSL2561_COMMAND_MODE | TSL2561_REGISTER_CONTROL, TSL2561_CONTROL_POWEROFF ); #if ENABLE_DEBUG uint8_t dis; i2c_read_reg(dev->i2c_dev, dev->addr, TSL2561_COMMAND_MODE | TSL2561_REGISTER_CONTROL, &dis); DEBUG("[Info] Disabled ? %s\n", dis == 0 ? "true": "false"); #endif } static void _read_data(const tsl2561_t *dev, uint16_t *full, uint16_t *ir) { /* Enable the device */ _enable(dev); /* Wait integration time in ms for ADC to complete */ switch (dev->integration) { case TSL2561_INTEGRATIONTIME_13MS: xtimer_usleep(13700); break; case TSL2561_INTEGRATIONTIME_101MS: xtimer_usleep(101000); break; default: /* TSL2561_INTEGRATIONTIME_402MS */ xtimer_usleep(402000); break; } char buffer[2] = { 0 }; /* Read full spectrum channel */ i2c_read_regs(dev->i2c_dev, dev->addr, TSL2561_COMMAND_MODE | TSL2561_COMMAND_WORD | TSL2561_REGISTER_CHAN0, buffer, 2); *full = (buffer[1] << 8) | buffer[0]; memset(buffer, 0, sizeof(buffer)); /* Read infrared spectrum channel */ i2c_read_regs(dev->i2c_dev, dev->addr, TSL2561_COMMAND_MODE | TSL2561_COMMAND_WORD | TSL2561_REGISTER_CHAN1, buffer, 2); *ir = (buffer[1] << 8) | buffer[0]; /* Turn the device off to save power */ _disable(dev); } static void _print_init_info(const tsl2561_t *dev) { DEBUG("[Info] I2C device: %d\n", dev->i2c_dev); DEBUG("[Info] Address: %d\n", dev->addr); switch(dev->gain) { case TSL2561_GAIN_1X: DEBUG("[Info] Gain: 1X\n"); break; case TSL2561_GAIN_16X: DEBUG("[Info] Gain: 16X\n"); break; default: DEBUG("[Info] Invalid gain %d\n", dev->gain); break; } switch(dev->integration) { case TSL2561_INTEGRATIONTIME_13MS: DEBUG("[Info] Integration time: 13ms\n"); break; case TSL2561_INTEGRATIONTIME_101MS: DEBUG("[Info] Integration time: 101ms\n"); break; case TSL2561_INTEGRATIONTIME_402MS: DEBUG("[Info] Integration time: 402ms\n"); break; case TSL2561_INTEGRATIONTIME_NA: DEBUG("[Info] Integration time: n/a\n"); break; default: DEBUG("[Info] Invalid integration time %d\n", dev->integration); break; } }