Add bare-metal I2C driver for RP2350 (0x07_i2c_cbm)

drivers/0x07_i2c_cbm/Src/main.c

@@ -0,0 +1,54 @@
+/**
+  ******************************************************************************
+  * @file    main.c
+  * @author  Kevin Thomas
+  * @brief   I2C demonstration: scan all 7-bit addresses and report devices.
+  *
+  *          Demonstrates I2C bus scanning using the bare-metal I2C driver.
+  *          I2C1 is configured at 100 kHz on SDA=GPIO2 / SCL=GPIO3. A
+  *          formatted hex table of all responding device addresses is
+  *          printed over UART and repeated every 5 seconds.
+  *
+  *          Wiring:
+  *            GPIO0  -> UART TX (USB-to-UART adapter RX)
+  *            GPIO1  -> UART RX (USB-to-UART adapter TX)
+  *            GPIO2  -> I2C device SDA (4.7 kohm pull-up to 3.3 V)
+  *            GPIO3  -> I2C device SCL (4.7 kohm pull-up to 3.3 V)
+  *            3.3V   -> I2C device VCC
+  *            GND    -> I2C device GND
+  *
+  ******************************************************************************
+  * @attention
+  *
+  * Copyright (c) 2026 Kevin Thomas.
+  * All rights reserved.
+  *
+  * This software is licensed under terms that can be found in the LICENSE file
+  * in the root directory of this software component.
+  * If no LICENSE file comes with this software, it is provided AS-IS.
+  *
+  ******************************************************************************
+  */
+
+#include "rp2350_i2c.h"
+#include "rp2350_uart.h"
+#include "rp2350_xosc.h"
+#include "rp2350_delay.h"
+
+#define SCAN_DELAY_MS 5000
+
+/**
+  * @brief  Application entry point for the I2C bus scanner demo.
+  * @retval int does not return
+  */
+int main(void)
+{
+  xosc_set_clk_ref();
+  i2c_release_reset();
+  i2c_init();
+  uart_puts("I2C driver initialized: I2C1 @ 100 kHz  SDA=GPIO2  SCL=GPIO3\r\n");
+  while (1) {
+    i2c_scan();
+    delay_ms(SCAN_DELAY_MS);
+  }
+}