Updated readme for LSA (#169)

* Added updated images of lsa

* Updated the readme

Author: badboy1606

2_LSA/README.md

@@ -3,45 +3,49 @@
 ### Table of Contents
 * [Overview](#overview)
 * [Components of LSA](#components-of-lsa)
-* [Function of Components](#function-of-components)
-	* [LED](#function-of-components)
-	* [PhotoDiode](#function-of-components)
-	* [IC LM324](#function-of-components)
-	* [Resistors](#function-of-components)
+* [Functions of Components](#function-of-components)
+	* [Infrared Emmitter](#function-of-components)
+	* [Photo Transistor](#function-of-components)
+    * [Resistors](#function-of-components)
+	* [JST connectors](#function-of-components)
+	
 * [Working Principle](#working-principle)
 * [Appplications](#applications)
 * [Scope of Improvement](#scope-of-improvement)
 * [Description of Functions Used](#description-of-functions-used)
 
 ### Overview 
 - The Light Sensor Array(LSA) is used to detect the white/black lined surface and it sends this data to the microcontroller ESP32. Thus, the purpose of line following is achieved.
+ 
+- **Actual LSA**
+<img src="assets/lsa_physical.png" width="750" height="375" >
 
-- Physical PCB
-<img src="assets/lsa_pcb.jpeg" width="800" height="450">
 
-- PCB Model
-<img src="assets/lsa_pcb_model.jpeg" width="800" height="400">
+- **PCB Model**
+<img src="assets/lsa_pcb_image.png" width="750" height="400">
 
 ### Components of LSA
 | Component   | Description   | Quantity |
 | ----------- | ------------- | -------- |
-| LED         | Emits light   |  4       |
-| PhotoDiode  | Absorbs light |  4       |
-| IC LM324    | Op.Amp. IC    |  1       |  
-| Resistors   | Limit Current |  8       |
+| Infrared Emmiter| Emits  infrared light   |  5|
+| Photo Transistor | Absorbs light |  5| 
+| Resistors | Limit Current |  10|
+| JST connector | Connects LSA with SRA Board or any other PCB | 1  | 
 
 ### Function of Components
-- LED
-	- LSA consists of Four LED and PhotoDiode Pairs. The specific LED's emit white light which is incident on the surface and some of it is absorbed by the surface. The voltage source For the LEDs to glow is VCC.
+- **Infrared Emmitter**
+    - The specific Infrared Emmitter emit infrared light which is incident on the surface and some of it is absorbed by the surface. The voltage source for the Infrared Emmitter to emit is VCC.
+	
 
-- PhotoDiode
-	- Based upon the reflectivity coefficient of the surface( generally less than 1), the remaining light reflected from the surface is captured by the Photodiodes. LEDs and complimentary photodiodes are used to efficiently detect the surface (white/black line) as the environment also contains unwanted light for the LSA sensor. The amount of light received is directly proportional to the current generated by it. More the light, more the current, more the reading.
- 
-- IC LM324 
-	- This is a Quad(4) OP.Amp. IC. Op.Amp i.e Operation Amplifiers amplify the current with constant volatge. Since the current reading from photo diodes is significantly small and difficult to compare, it needs to be amplified. The 4 amplified outputs serve as raw readings of LSA.
+- **Photo Transistor**
+    - Based upon the reflectivity coefficient of the surface( generally less than 1), the remaining light reflected from the surface is captured by the Photodiodes. Infrared Emmitter and complimentary phototransistor are used to efficiently detect the surface (white/black line). The amount of light received is directly proportional to the current generated by it. More the light, more the current, more the reading.
+
+
+- **Resistors**
+	- Now to limit the current and thus to protect the LEDs, Photo Diodes current limiting resistors are used.
 
-- Resistors
-	- Now to limit the current and thus to protect the LEDs, PhotoDiodes current limiting resistors are used.
+- **JST connectors**
+    - To provide a compact, reliable and secure electrical conection on a PCB.
 
 ### Working Principle
 - LSA works on the principle of reflectivity of light for different types of surfaces.
@@ -52,6 +56,7 @@
 
 ### Applications 
 - Application of LSA majorly lies in line following.
+- Obstacle detection on a clear path.
 
 ### Scope of Improvement
 - LSA sometimes provides slightly inaccurate readings due to external light and conditions. Therefore, LSA has low accuracy. Hence LSA should be kept close to the ground.