Category: Datasheet/Specs
Product Number: MAX35103
Software Version: v1.1
How do I interface the MAX35103 IC with the ESP32-S3 using ESP-IDF? I am using SPI communication, but the output is always 0xFF. What can I do to fix this?
this is our code
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "driver/spi_master.h"
#include "driver/gpio.h"
#include "esp_log.h"
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#define TAG "MAX35103"
// Updated SPI Pins
#define SPI_HOST SPI2_HOST
#define SPI_MISO_PIN 8
#define SPI_MOSI_PIN 9
#define SPI_CLK_PIN 7
#define SPI_CS_PIN 6
#define PIN_NUM_INT 4 // Interrupt pin (optional)
// SPI Commands for MAX35103
#define CMD_TOF_DIFF 0x02 // Measure TOF Difference
#define CMD_TEMP_MEAS 0x03 // Measure Temperature
#define CMD_READ_REG 0xB0 // Read Register
#define CMD_WRITE_REG 0x30 // Write Register
// MAX35103 Register Addresses
#define REG_TOF_DIFF_INT 0x08 // TOF Integer Result
#define REG_TOF_DIFF_FRAC 0x09 // TOF Fractional Result
#define REG_TEMP1_INT 0x0A // Temperature 1 Integer
#define REG_TEMP1_FRAC 0x0B // Temperature 1 Fractional
#define REG_TEMP2_INT 0x0C // Temperature 2 Integer
#define REG_TEMP2_FRAC 0x0D // Temperature 2 Fractional
spi_device_handle_t max35103;
// SPI Initialization
void spi_init() {
spi_bus_config_t buscfg = {
.miso_io_num = SPI_MISO_PIN,
.mosi_io_num = SPI_MOSI_PIN,
.sclk_io_num = SPI_CLK_PIN,
.quadwp_io_num = -1,
.quadhd_io_num = -1,
};
spi_device_interface_config_t devcfg = {
.clock_speed_hz = 1 * 1000 * 1000, // 1MHz
.mode = 0, // SPI mode 0
.spics_io_num = SPI_CS_PIN, // CS pin
.queue_size = 1,
};
ESP_ERROR_CHECK(spi_bus_initialize(SPI_HOST, &buscfg, SPI_DMA_CH_AUTO));
ESP_ERROR_CHECK(spi_bus_add_device(SPI_HOST, &devcfg, &max35103));
ESP_LOGI(TAG, "SPI Initialized with MISO: %d, MOSI: %d, CLK: %d, CS: %d",
SPI_MISO_PIN, SPI_MOSI_PIN, SPI_CLK_PIN, SPI_CS_PIN);
}
// Read 16-bit Register from MAX35103
uint16_t spi_read_register(uint8_t reg) {
uint8_t tx_data[2] = { CMD_READ_REG | (reg & 0x0F), 0x00 };
uint8_t rx_data[2] = {0};
spi_transaction_t trans = {
.length = 16,
.tx_buffer = tx_data,
.rxlength = 16,
.rx_buffer = rx_data
};
esp_err_t ret = spi_device_transmit(max35103, &trans);
if (ret != ESP_OK) {
ESP_LOGE(TAG, "SPI Read Failed for Register 0x%02X", reg);
return 0xFFFF;
}
return (rx_data[0] << 8) | rx_data[1];
}
// Start TOF Measurement
void max35103_measure_tof() {
uint8_t cmd = CMD_TOF_DIFF;
spi_transaction_t trans = {
.length = 8,
.tx_buffer = &cmd,
};
esp_err_t ret = spi_device_transmit(max35103, &trans);
if (ret == ESP_OK) {
ESP_LOGI(TAG, "TOF Measurement Started");
} else {
ESP_LOGE(TAG, "Failed to Start TOF Measurement");
}
}
// Start Temperature Measurement
void max35103_measure_temperature() {
uint8_t cmd = CMD_TEMP_MEAS;
spi_transaction_t trans = {
.length = 8,
.tx_buffer = &cmd,
};
esp_err_t ret = spi_device_transmit(max35103, &trans);
if (ret == ESP_OK) {
ESP_LOGI(TAG, "Temperature Measurement Started");
} else {
ESP_LOGE(TAG, "Failed to Start Temperature Measurement");
}
}
// Interrupt Handler (Optional)
void IRAM_ATTR max35103_isr_handler(void *arg) {
ESP_LOGI(TAG, "MAX35103 Interrupt Triggered!");
}
// Setup Interrupt for MAX35103
void interrupt_init() {
gpio_config_t io_conf = {
.intr_type = GPIO_INTR_NEGEDGE, // Falling edge trigger
.pin_bit_mask = (1ULL << PIN_NUM_INT),
.mode = GPIO_MODE_INPUT,
.pull_up_en = GPIO_PULLUP_ENABLE,
.pull_down_en = GPIO_PULLDOWN_DISABLE,
};
gpio_config(&io_conf);
gpio_install_isr_service(0);
gpio_isr_handler_add(PIN_NUM_INT, max35103_isr_handler, NULL);
ESP_LOGI(TAG, "Interrupt Initialized on GPIO %d", PIN_NUM_INT);
}
// Main Loop
void app_main() {
spi_init();
interrupt_init(); // Optional: Initialize interrupt handling
while (1) {
max35103_measure_tof();
vTaskDelay(100 / portTICK_PERIOD_MS);
uint16_t tof_int = spi_read_register(REG_TOF_DIFF_INT);
uint16_t tof_frac = spi_read_register(REG_TOF_DIFF_FRAC);
ESP_LOGI(TAG, "TOF Difference: %u.%u", tof_int, tof_frac);
max35103_measure_temperature();
vTaskDelay(100 / portTICK_PERIOD_MS);
uint16_t temp1_int = spi_read_register(REG_TEMP1_INT);
uint16_t temp1_frac = spi_read_register(REG_TEMP1_FRAC);
uint16_t temp2_int = spi_read_register(REG_TEMP2_INT);
uint16_t temp2_frac = spi_read_register(REG_TEMP2_FRAC);
ESP_LOGI(TAG, "Temperature 1: %u.%u", temp1_int, temp1_frac);
ESP_LOGI(TAG, "Temperature 2: %u.%u", temp2_int, temp2_frac);
vTaskDelay(1000 / portTICK_PERIOD_MS);
}
}
