# LAB: ADC - IR reflective sensor **Date:** 2025-11-06 **Author/Partner:** **Github:** repository link **Demo Video:** Youtube link **PDF version:** ## Introduction Create a simple program that uses ADCs to use analog sensors. For this lab, we will use two IR reflective sensors. The ADCs are triggered by a timer at the given sampling rate. This lab will be extended to Project: Line Tracing Car You must submit * LAB Report (\*.md & \*.pdf) * Zip source files(main\*.c, ecRCC.h, ecGPIO.h, ecSysTick.c etc...). * Only the source files. Do not submit project files ### Requirement #### Hardware * MCU * NUCLEO-F411RE * Actuator/Sensor/Others: * IR Reflective Sensor (TCRT 5000) x2 #### Software * Keil uVision, CMSIS, EC\_HAL library ## Problem 0: STM-Arduino ### Procedure 1. Create a new project under the directory`\repos\EC\LAB\LAB_ADC` 2. Follow the tutorial: [**ADC with photodector and sound sensor**](https://ykkim.gitbook.io/ec/ec-course/tutorial/tutorial-arduino-stm32/tutorial-arduino-stm32-part-2#adc) {% embed url="" %} ## Problem 1: EC library ### (Option 1) Use the provided library Download Library Header Files (solution) * [ecADC2.h, ecADC2.c](https://github.com/ykkimhgu/EC-student/tree/main/include/lib-student) ```cpp ///////////////////////////////////////////////////// // ADC default setting ///////////////////////////////////////////////////// // ADC init // Default: one-channel mode, continuous conversion // Default: HW trigger - TIM3 counter, 1msec void ADC_init(PinName_t pinName); void JADC_init(PinName_t pinName); // Multi-Channel Scan Sequence void ADC_sequence(PinName_t *seqCHn, int seqCHnums); void JADC_sequence(PinName_t *seqCHn, int seqCHnums); // ADC start void ADC_start(void); // flag for ADC interrupt uint32_t is_ADC_EOC(void); uint32_t is_ADC_OVR(void); void clear_ADC_OVR(void); uint32_t is_ADC_JEOC(void); void clear_ADC_JEOC(void); // read ADC value uint32_t ADC_read(void); ///////////////////////////////////////////////////// // Advanced Setting ///////////////////////////////////////////////////// // Conversion mode change: CONT, SINGLE / Operate both ADC,JADC void ADC_conversion(int convMode); void ADC_trigger(TIM_TypeDef* TIMx, int msec, int edge); // Private Function void ADC_pinmap(PinName_t pinName, uint32_t *chN); ``` ### (Option 2) Create your own library Download the exercise files. * [ecADC2\_student.c](https://github.com/ykkimhgu/EC-student/blob/main/include/lib-student) * [ecADC2\_student.h](https://github.com/ykkimhgu/EC-student/blob/main/include/lib-student) Change the file names as * ecADC2.c * ecADC2.h **ecADC2.h** **Fill-In missing code in ecADC2\_student.c** You must update your header files in the directory `EC\include\`. and add in `ecSTM32F4v2.h` {% tabs %} {% tab title="ADC\_init()" %} ```c void ADC_init(PinName_t pinName){ // ... // ... // 2. Regular / Injection Group //Regular: SQRx, Injection: JSQx // 3. Repetition: Single scan or Continuous scan conversion ADC1->CR2 |= ___________; // default : Continuous conversion mode // 4. Single(one) Channel or Scan(multi-channel) mode // Configure the sequence length // default: one-channel length ADC1->SQR1 &= ___________; // 0000: one channel length in the regular channel conversion sequence // Configure the multiple channel sampling sequence ADC1->SQR3 &= ~ADC_SQR3_SQ1; // SQ1 clear ADC1->SQR3 |= ___________; // Choose the first channelID to sample // Default: Single(one-channel) Channel mode ADC1->CR1 &= ___________; // 0: One-channel mode // 5. Interrupt Enable // Enable EOC(conversion) interrupt. ADC1->CR1 &= ~ADC_CR1_EOCIE; // Interrupt reset ADC1->CR1 |= ___________; // Interrupt enable // ... // ... } ``` {% endtab %} {% tab title="JADC\_init" %} ```c void JADC_init(PinName_t pinName){ // ... // ... // 2. Injection Group // Injection: JSQx // 3. Repetition: Single or Continuous conversion ADC1->CR2 |= _____________; // Enable Continuous conversion mode // 4. Single Channel or Scan mode // - Single Channel: scan mode, right alignment ADC1->CR1 |= _____________; // 1: Scan mode enable ADC1->CR2 &= _____________; // 0: Right alignment // Configure the injected channel sequence length ADC1->JSQR &= _____________; // 00: conversion in the inject channel // Configure the injected channel sequence ADC1->JSQR &= ~ADC_JSQR_JSQ1; // SQ1 clear bits ADC1->JSQR |= _____________; // Choose the channel to convert firstly // 5. Interrupt Enable // Enable JEOC(conversion) interrupt. ADC1->CR1 &= ~ADC_CR1_JEOCIE; // JEOC interrupt reset ADC1->CR1 |= _____________; // JEOC interrupt enable // ... // ... } ``` {% endtab %} {% endtabs %} ### Example Code Check your library files by running the following examples. #### **Example 1: One Analog sensor (ADC)** * Single-Channel, Continuous Scan * 1msec ADC triggering with TIM3 ```cpp #include "ecSTM32F4v2.h" // #include "ecADC.h" //IR parameter// uint32_t value; void setup(void); int main(void) { // Initialiization -------------------------------------------------------- setup(); // Inifinite Loop ---------------------------------------------------------- while(1){ printf("value = %d \r\n",value); printf("\r\n"); delay_ms(1000); } } // Initialiization void setup(void) { RCC_PLL_init(); // System Clock = 84MHz UART2_init(); // UART2 Init SysTick_init(); // SysTick Init ADC_init(PB_0); // Default: HW triggered by TIM3 counter @ 1msec } // ADC Interrupt - End-of-Conversion void ADC_IRQHandler(void){ if(is_ADC_EOC()) { // if(is_ADC_OVR()) clear_ADC_OVR(); // User Code Goes Here value = ADC_read(); // clear_ADC_EOC(); // Reading ADC clears EOC flag } } ``` #### **Example 2: Multiple Analog sensors (JADC)** * Multi-Channel(2 channels), Continuous Scan * 1msec ADC triggering with TIM3 * (ADC) Channel Sequence: * SQ1=ADC\_CH\_8(PB\_0) to SQ2=ADC\_CH\_9(PB\_1) * (JADC): Channel Sequence: * JSQ1=ADC\_CH\_8(PB\_0)(PB\_0) to JSQ1=ADC\_CH\_9(PB\_1) {% hint style="info" %} **Use JADC instead of ADC for multiple-channel ADC** {% endhint %} {% tabs %} {% tab title="JADC" %} **JADC: Has its own data register for each ADC channels** ```cpp #include "ecSTM32F4v2.h" // #include "ecADC.h" //IR parameter// uint32_t value1, value2; PinName_t seqCHn[2] = {PB_0, PB_1}; void setup(void); int main(void) { // Initialiization -------------------------------------------------------- setup(); // Inifinite Loop ---------------------------------------------------------- while(1){ printf("value1 = %d \r\n",value1); printf("value2 = %d \r\n",value2); printf("\r\n"); delay_ms(1000); } } // Initialiization void setup(void) { RCC_PLL_init(); // System Clock = 84MHz UART2_init(); // UART2 Init SysTick_init(); // SysTick Init // ADC Init Default: HW triggered by TIM3 counter @ 1msec JADC_init(PB_0); JADC_init(PB_1); // ADC channel sequence setting JADC_sequence(seqCHn, 2); } void ADC_IRQHandler(void){ // if(is_ADC_OVR()) clear_ADC_OVR(); if(is_ADC_JEOC()){ // after finishing sequence ADC value1 = JADC_read(1); value2 = JADC_read(2); clear_ADC_JEOC(); } } ``` {% endtab %} {% tab title="ADC" %} **ADC: Shares the same data register from multiple channels** ```c #include "ecSTM32F4v2.h" // #include "ecADC.h" //IR parameter// uint32_t value1, value2; int flag = 0; PinName_t seqCHn[2] = {PB_0, PB_1}; void setup(void); int main(void) { // Initialiization -------------------------------------------------------- setup(); // Inifinite Loop ---------------------------------------------------------- while(1){ printf("value1 = %d \r\n",value1); printf("value2 = %d \r\n",value2); printf("\r\n"); delay_ms(1000); } } // Initialiization void setup(void) { RCC_PLL_init(); // System Clock = 84MHz UART2_init(); // UART2 Init SysTick_init(); // SysTick Init // ADC Init Default: HW triggered by TIM3 counter @ 1msec ADC_init(PB_0); ADC_init(PB_1); // ADC channel sequence setting ADC_sequence(seqCHn, 2); } void ADC_IRQHandler(void){ if(is_ADC_OVR()) clear_ADC_OVR(); if(is_ADC_EOC()){ // after finishing sequence if (flag==0) value1 = ADC_read(); else if (flag==1) value2 = ADC_read(); flag =! flag; // flag toggle } } ``` {% endtab %} {% endtabs %} ## Problem 2: Measurement from multiple analog sensors ### IR Reflective Sensors (TCRT 5000) First, download and read IR Reflective Sensor(TCRT 5000): [Spec Sheet](https://www.devicemart.co.kr/goods/download?id=1327416\&rank=1) TCRT5000 and TCRT5000L are reflective sensors that include an infrared emitter and phototransistor in a leaded package, which blocks visible light. ![image](https://user-images.githubusercontent.com/91526930/200573269-26a4ffa1-c789-4545-9dc5-079294265d4d.png) **The HC-SR04 Ultrasonic Range Sensor Features:** * Input Voltage : 5V * Detector type: phototransistor * Operating range within > 20 % relative collector current: 0.2 mm to 15 mm * Emitter wavelength: 950 nm **APPLICATIONS** * Position sensor for shaft encoder * Detection of reflective material such as paper, IBM cards, magnetic tapes etc. * Limit switch for mechanical motions in VCR ### Procedure 1. Create a new project under the directory `\repos\EC\LAB\LAB_ADC` * The project name is “**LAB\_ADC\_IR”** * Create a new source file named as “**LAB\_ADC\_IR.c”** > You MUST write your name on the source file inside the comment section. 2\. Update and use **ecSTM32F411.h**. This header should be defined as explained in ### Configuration | Type | Port - Pin | Configuration | | ---------------- | ----------------------------------------------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | **System Clock** | | PLL 84MHz | | **GPIO** |

PB\_0
PB\_1

|

Analog Mode
No Pull-up Pull-down

| | **ADC (JADC)** |

PB\_0: ADC1\_CH8 (1st channel)
PB\_1: ADC1\_CH9 (2nd channel)

|

ADC Clock Prescaler /8
12-bit resolution, right alignment
Continuous Conversion mode
Scan mode: Two channels in regular group
External Trigger (Timer3 Trigger) @ 1kHz
Trigger Detection on Rising Edge

| | **TIM3** | |

Up-Counter, Counter CLK 1kHz
OC1M(Output Compare 1 Mode) : PWM mode 1
Master Mode Selection: (Trigger) OC1REF

| ### Line Tracing ![line](https://github.com/ykkimhgu/EC-student/assets/84508106/8092b591-4e70-49b3-8690-4e9e09642bd1) * Create a logic to trace a dark line on white background surface for your RC car. * Use 2 IR reflective sensors to detect if the black line is in between the sensors. It should display whether the system needs to move **Left or Right** to keep the line between sensors. * Set the ADC sampling rate trigger to be 1KHz * Determine the threshold value to differentiate dark and white surface of the object. * Display (1) and (2) on serial monitor of Tera-Term. Print the values every second. ​ (1) reflection value of IR1 and IR2 ​ (2) print ‘GO LEFT’ or ‘GO ‘RIGHT’ **Display Example** ![image](https://user-images.githubusercontent.com/91526930/200577686-909a4cb7-1af9-459a-8afa-aaaee64aa448.png) ### Circuit Diagram > You need to include the circuit diagram ![image](https://user-images.githubusercontent.com/38373000/192134563-72f68b29-4127-42ac-b064-2eda95a9a52a.png) ### Discussion 1. How would you change the code if you need to use 3 Analog sensors? > Answer discussion questions 2. Which registers should be modified if you need to use Injection Groups instead of regular groups for 2 analog sensors? > Answer discussion questions ### Code Your code goes here: [ADD Code LINK such as github](https://github.com/ykkimhgu/EC-student/) Explain your source code with necessary comments. ``` // YOUR MAIN CODE ONLY // YOUR CODE ``` ### Results Experiment images and results > Show experiment images /results Add [demo video link](https://github.com/ykkimhgu/course-doc/blob/master/ec-course/lab/link/README.md) ## Reference Complete list of all references used (github, blog, paper, etc) ``` ``` ## Troubleshooting (Option) You can write Troubleshooting section