Files
basic1/lib/ft6336u/ft6336u.c
2026-01-28 23:23:49 -05:00

332 lines
10 KiB
C

/*
* FT6336U Capacitive Touch Screen Driver Implementation
*/
#include "ft6336u.h"
#include "hardware/gpio.h"
#include <string.h>
#include <stdio.h>
static ft6336u_config_t g_config_storage;
static const ft6336u_config_t *g_config = NULL;
// Helper function to write a register
static bool ft6336u_write_reg(uint8_t reg, uint8_t value) {
uint8_t buf[2] = {reg, value};
int result = i2c_write_blocking(g_config->i2c, FT6336U_ADDR, buf, 2, false);
return result == 2;
}
// Helper function to read a register
static bool ft6336u_read_reg(uint8_t reg, uint8_t *value) {
// Retry up to 3 times like Arduino library
for (int retry = 0; retry < 3; retry++) {
int result = i2c_write_blocking(g_config->i2c, FT6336U_ADDR, &reg, 1, true);
if (result != 1) {
sleep_us(1000); // 1ms delay before retry
continue;
}
// Add delay after write, before read (like Arduino library does)
sleep_us(10000); // 10ms delay
result = i2c_read_blocking(g_config->i2c, FT6336U_ADDR, value, 1, false);
if (result == 1) {
return true;
}
sleep_us(1000); // 1ms delay before retry
}
return false;
}
// Helper function to read multiple registers
static bool ft6336u_read_regs(uint8_t reg, uint8_t *buf, size_t len) {
// Retry up to 3 times
for (int retry = 0; retry < 3; retry++) {
int result = i2c_write_blocking(g_config->i2c, FT6336U_ADDR, &reg, 1, true);
if (result != 1) {
sleep_us(1000); // 1ms delay before retry
continue;
}
// Add delay after write, before read (like Arduino library does)
sleep_us(10000); // 10ms delay
result = i2c_read_blocking(g_config->i2c, FT6336U_ADDR, buf, len, false);
if (result == (int)len) {
return true;
}
sleep_us(1000); // 1ms delay before retry
}
return false;
}
bool ft6336u_init(const ft6336u_config_t *config) {
if (config == NULL) {
printf("[FT6336U] ERROR: config is NULL\n");
return false;
}
printf("[FT6336U] Initializing touch controller...\n");
printf("[FT6336U] Pins: SDA=%d, SCL=%d, RST=%d, INT=%d\n",
config->gpio_sda, config->gpio_scl, config->gpio_rst, config->gpio_int);
// Copy config to static storage to avoid dangling pointer
memcpy(&g_config_storage, config, sizeof(ft6336u_config_t));
g_config = &g_config_storage;
// Initialize I2C
printf("[FT6336U] Initializing I2C at 400 kHz...\n");
uint actual_freq = i2c_init(config->i2c, 400000); // 400 kHz
printf("[FT6336U] I2C actual frequency: %u Hz\n", actual_freq);
gpio_set_function(config->gpio_sda, GPIO_FUNC_I2C);
gpio_set_function(config->gpio_scl, GPIO_FUNC_I2C);
gpio_pull_up(config->gpio_sda);
gpio_pull_up(config->gpio_scl);
printf("[FT6336U] I2C pins configured\n");
// Initialize reset pin
gpio_init(config->gpio_rst);
gpio_set_dir(config->gpio_rst, GPIO_OUT);
printf("[FT6336U] Reset pin configured\n");
// Initialize interrupt pin (input with pull-up)
gpio_init(config->gpio_int);
gpio_set_dir(config->gpio_int, GPIO_IN);
gpio_pull_up(config->gpio_int);
printf("[FT6336U] Interrupt pin configured\n");
// Reset the touch controller
printf("[FT6336U] Resetting touch controller...\n");
gpio_put(config->gpio_rst, 0);
sleep_ms(10);
gpio_put(config->gpio_rst, 1);
sleep_ms(300); // Wait for chip to initialize
printf("[FT6336U] Reset complete, reading chip ID...\n");
// Verify chip ID
uint8_t chip_id = ft6336u_get_chip_id();
printf("[FT6336U] Chip ID read attempt 1: 0x%02X (expected 0x64)\n", chip_id);
if (chip_id != 0x64) {
// Try again - sometimes first read fails
printf("[FT6336U] First read failed, retrying...\n");
sleep_ms(100);
chip_id = ft6336u_get_chip_id();
printf("[FT6336U] Chip ID read attempt 2: 0x%02X\n", chip_id);
if (chip_id != 0x64) {
printf("[FT6336U] ERROR: Invalid chip ID! Check I2C wiring and address.\n");
printf("[FT6336U] Possible issues:\n");
printf(" - I2C pins not connected properly\n");
printf(" - Touch controller not powered\n");
printf(" - Wrong I2C address (using 0x%02X)\n", FT6336U_ADDR);
printf(" - I2C pull-up resistors missing\n");
return false;
}
}
printf("[FT6336U] Chip ID verified successfully!\n");
// Set to normal operating mode
printf("[FT6336U] Setting normal operating mode...\n");
if (!ft6336u_write_reg(FT6336U_REG_DEVICE_MODE, 0x00)) {
printf("[FT6336U] WARNING: Failed to set device mode\n");
}
// Enable trigger mode for better gesture and interrupt support
printf("[FT6336U] Enabling trigger mode...\n");
if (!ft6336u_write_reg(FT6336U_REG_G_MODE, FT6336U_G_MODE_TRIGGER)) {
printf("[FT6336U] WARNING: Failed to set G_MODE\n");
}
// Verify gesture mode was set
uint8_t g_mode = ft6336u_get_g_mode();
printf("[FT6336U] G_MODE: 0x%02X (%s mode)\n",
g_mode, g_mode == FT6336U_G_MODE_TRIGGER ? "trigger" : "polling");
printf("[FT6336U] Initialization complete!\n");
return true;
}
bool ft6336u_read_touch(ft6336u_touch_data_t *data) {
if (data == NULL || g_config == NULL) return false;
memset(data, 0, sizeof(ft6336u_touch_data_t));
// Read gesture ID
ft6336u_read_reg(FT6336U_REG_GESTURE_ID, &data->gesture);
// Read number of touch points (with retries)
uint8_t td_status;
if (!ft6336u_read_reg(FT6336U_REG_TD_STATUS, &td_status)) {
return false; // I2C error
}
data->touch_count = td_status & 0x0F;
if (data->touch_count > FT6336U_MAX_TOUCH_POINTS) {
data->touch_count = FT6336U_MAX_TOUCH_POINTS;
}
// If no touches, return early
if (data->touch_count == 0) {
return true;
}
// Read touch point data (6 bytes per point: XH, XL, YH, YL, WEIGHT, MISC)
for (int i = 0; i < data->touch_count; i++) {
uint8_t reg_base = (i == 0) ? FT6336U_REG_P1_XH : FT6336U_REG_P2_XH;
uint8_t buf[6];
if (!ft6336u_read_regs(reg_base, buf, 6)) {
return false;
}
// Parse touch point data
data->points[i].event = (buf[0] >> 6) & 0x03;
uint16_t raw_x = ((buf[0] & 0x0F) << 8) | buf[1];
uint16_t raw_y = ((buf[2] & 0x0F) << 8) | buf[3];
data->points[i].id = (buf[2] >> 4) & 0x0F;
data->points[i].weight = buf[4]; // Touch pressure/area
data->points[i].misc = (buf[5] >> 4) & 0x0F; // Touch area (upper nibble)
// Apply coordinate transformations
if (g_config->swap_xy) {
uint16_t temp = raw_x;
raw_x = raw_y;
raw_y = temp;
}
if (g_config->invert_x) {
raw_x = g_config->screen_width - 1 - raw_x;
}
if (g_config->invert_y) {
raw_y = g_config->screen_height - 1 - raw_y;
}
data->points[i].x = raw_x;
data->points[i].y = raw_y;
// Ensure coordinates are within screen bounds
if (data->points[i].x >= g_config->screen_width) {
data->points[i].x = g_config->screen_width - 1;
}
if (data->points[i].y >= g_config->screen_height) {
data->points[i].y = g_config->screen_height - 1;
}
}
return true;
}
bool ft6336u_is_touched(void) {
if (g_config == NULL) return false;
// More reliable: Read TD_STATUS register directly
// INT pin can be unreliable due to timing/noise
uint8_t td_status;
if (!ft6336u_read_reg(FT6336U_REG_TD_STATUS, &td_status)) {
return false; // I2C error, assume not touched
}
uint8_t touch_count = td_status & 0x0F;
return touch_count > 0;
}
uint8_t ft6336u_get_chip_id(void) {
if (g_config == NULL) return 0xFF;
uint8_t chip_id;
if (!ft6336u_read_reg(FT6336U_REG_CHIPID, &chip_id)) {
return 0xFF;
}
return chip_id;
}
uint8_t ft6336u_get_firmware_version(void) {
if (g_config == NULL) return 0xFF;
uint8_t fw_ver;
if (!ft6336u_read_reg(FT6336U_REG_FIRMID, &fw_ver)) {
return 0xFF;
}
return fw_ver;
}
void ft6336u_set_interrupt_callback(void (*callback)(uint gpio, uint32_t events)) {
if (g_config == NULL || callback == NULL) return;
// Enable interrupt on falling edge (touch detected)
gpio_set_irq_enabled_with_callback(g_config->gpio_int,
GPIO_IRQ_EDGE_FALL,
true,
callback);
}
bool ft6336u_test_i2c(void) {
if (g_config == NULL) {
printf("[FT6336U] Test failed: not initialized\n");
return false;
}
printf("[FT6336U] Testing I2C communication...\n");
// Test 1: Read chip ID
uint8_t chip_id = ft6336u_get_chip_id();
printf(" Chip ID: 0x%02X (expected 0x64) - %s\n",
chip_id, chip_id == 0x64 ? "PASS" : "FAIL");
// Test 2: Read firmware version
uint8_t fw_ver = ft6336u_get_firmware_version();
printf(" Firmware: 0x%02X - %s\n",
fw_ver, fw_ver != 0xFF ? "PASS" : "FAIL");
// Test 3: Read TD_STATUS multiple times
int success_count = 0;
const int test_count = 10;
for (int i = 0; i < test_count; i++) {
uint8_t status;
if (ft6336u_read_reg(FT6336U_REG_TD_STATUS, &status)) {
success_count++;
}
sleep_ms(10);
}
printf(" TD_STATUS reads: %d/%d successful - %s\n",
success_count, test_count,
success_count == test_count ? "PASS" : "WARN");
bool overall = (chip_id == 0x64) && (fw_ver != 0xFF) && (success_count >= test_count - 2);
printf("[FT6336U] I2C test: %s\n", overall ? "PASS" : "FAIL");
return overall;
}
bool ft6336u_set_g_mode(uint8_t mode) {
if (g_config == NULL) return false;
return ft6336u_write_reg(FT6336U_REG_G_MODE, mode);
}
uint8_t ft6336u_get_g_mode(void) {
if (g_config == NULL) return 0xFF;
uint8_t g_mode;
if (!ft6336u_read_reg(FT6336U_REG_G_MODE, &g_mode)) {
return 0xFF;
}
return g_mode;
}
uint8_t ft6336u_get_power_mode(void) {
if (g_config == NULL) return 0xFF;
uint8_t pwr_mode;
if (!ft6336u_read_reg(FT6336U_REG_POWER_MODE, &pwr_mode)) {
return 0xFF;
}
return pwr_mode;
}