i2c-support:sample: update README

Signed-off-by: Dhruva Gole <goledhruva@gmail.com>

Author: DhruvaG2000

samples/i2cdemo/README.rst

@@ -1,71 +1,28 @@
-.. _blinky-sample:
-
-Blinky
+i2c demo
 ######
 
 Overview
 ********
 
-This Arduino Blinky sample blinks an LED forever using the `ArduinoAPI`.
+This Arduino i2c sample gets data from an ADXL345 sensor connected over `i2c0`.
 
 Requirements
 ************
 
 Your board must:
 
-#. Have an LED connected via a GPIO pin (these are called "User LEDs" on many of
-   Zephyr's :ref:`boards`).
-#. Have the LED configured using the ``led0`` devicetree alias.
+#. Have atleast 1 i2c port.
+#. Have the ADXL345 sensor connected to the I2C port.
 
 Building and Running
 ********************
 
 Build and flash Blinky as follows,
 
 ```sh
-$> west build  -p -b arduino_nano_33_ble samples/basic/arduino-blinky/ -DZEPHYR_EXTRA_MODULES=/home/$USER/zephyrproject/modules/lib/Arduino-Core-Zephyr
+$> west build -p -b arduino_nano_33_ble samples/i2cdemo
 
 $> west flash --bossac=/home/$USER/.arduino15/packages/arduino/tools/bossac/1.9.1-arduino2/bossac
 ```
 
-After flashing, the LED starts to blink. If a runtime error occurs, the sample
-exits without printing to the console.
-
-Adding board support
-********************
-
-To add support for your board, add something like this to your devicetree:
-
-.. code-block:: DTS
-
-   / {
-   	aliases {
-   		led0 = &myled0;
-   	};
-
-   	leds {
-   		compatible = "gpio-leds";
-   		myled0: led_0 {
-   			gpios = <&gpio0 13 GPIO_ACTIVE_LOW>;
-                };
-   	};
-   };
-
-The above sets your board's ``led0`` alias to use pin 13 on GPIO controller
-``gpio0``. The pin flags :c:macro:`GPIO_ACTIVE_HIGH` mean the LED is on when
-the pin is set to its high state, and off when the pin is in its low state.
-
-Tips:
-
-- See :dtcompatible:`gpio-leds` for more information on defining GPIO-based LEDs
-  in devicetree.
-
-- If you're not sure what to do, check the devicetrees for supported boards which
-  use the same SoC as your target. See :ref:`get-devicetree-outputs` for details.
-
-- See :zephyr_file:`include/zephyr/dt-bindings/gpio/gpio.h` for the flags you can use
-  in devicetree.
-
-- If the LED is built in to your board hardware, the alias should be defined in
-  your :ref:`BOARD.dts file <devicetree-in-out-files>`. Otherwise, you can
-  define one in a :ref:`devicetree overlay <set-devicetree-overlays>`.
+After flashing, probe the UART pin (TX) and you should be able to see X, Y and Z values if everything goes well.