Week 9: Input Devices

Adding traces

I repositioned LED connection from pin 2 to pin 37 to be able to better arrange them

Based on instructor input, I was showed how the two sets of pins are spaced at a distance equal to a gap of 4 pins, so I have arranged them as such before deleting them and grouping them together

Design Rules Checker

I then used the Design Rule Checker, I found errors on parameters of the vias. based on feedback from Midhun (FA2024), I realized that I did not add parameters for NetClass, so I added them now based on his parameters for our milling machine, then I redid the vias and the traces going behind the Board in B.Cu

But an error relatd to pad width appeared. I was able to solve itby reducing the width of the pad in the Y direction by 0.1mm to 0.8 mm. Then select the modified pad, right click > Push pad properties to ther pads > Change Pads on Current Footprint. Then run Design Ruless Checker again to verify that all the errors related to pad size has been reectified.

I had to do the same to the pads oriented in the footprint horizontally.did the same for errors related to pad width in the X direction by reducing width by 0.1 mm

Error 2: For some unknown reason, some of the track widths stayed 0.2 mm so I had to manually change them

Error 3: Annular width errors of pin headers were corrected by reducing .

Error 4: Errors related to via holes were corrected by adjusting the hole diameter to 0.85, and diamater to 1.6, which is the minimum required hole size for rivets based on experiments. Then I manually changed all of the hole dimensions

All these warnings and errors are related to pins on the bottom of the ESP32 chip that I wont be connecting so I can ignore all of them

When checking my design, my instructor pointed out that I had connected the I2S connections in such a way that the module would have to be set upside down, so I took a photo of the module in the correct orientation and connected them again, changing the changing the position of L/R and SCK and the pin connections with each other

This is my final PCB design

Milling

Now its time to mill my design. Just like before I use the 0.2 mm V bit for making the traces and 1/32" flat end mill to cut the PCB

Soldering

I also added wires behind the board to connect between two holes

Error: Tried desoldering the MEMS mic module using a heat gun, ended up removing all the components, a tiny MIC and capacitor and resistor

Verification

testing on microscope

Testing on oscilloscope: No constant current draw, current draw is less than prev set limit of 0.1 A (around 0.02A or 20 mA)

Programming

To be able to set the ESP32 with Arduino IDE, i used the help of ChatGPT

How do I set up an ESP32 board to work with the Arduino IDE?

https://raw.githubusercontent.com/espressif/arduino-esp32/gh-pages/package_esp32_index.json

void setup() {
    pinMode(2, OUTPUT); // GPIO 2 is usually the built-in LED
}

void loop() {
    digitalWrite(2, HIGH);
    delay(1000);
    digitalWrite(2, LOW);
    delay(1000);
}
                

The setup was pretty simple, simply install the board manager using the following URL: https://raw.githubusercontent.com/espressif/arduino-esp32/gh-pages/package_esp32_index.json and select the board and port

Note: When you upload the code, when you see the 'Connecting' message, keep pressing the Boot button and press the Reset button once. One you see the message 'Leaving' you press the 'Reset' button once more to start the program, and the program will start running.

Blink Program to verify that the board works

I now used the Blink program to test the proper functioning of the board. But the program did not work. My instructor helped identify the following errors

Error 1: I used a 1k instead of 10k value for the resistor connected in series to the Reset Switch

Error 2: I had shorted the tx and rx connections while soldering

Error 3: I used the wrong pin for LED, should have been IO23

                                void setup() {
                                    pinMode(23, OUTPUT); // GPIO 2 is usually the built-in LED
                                }
                                
                                void loop() {
                                    digitalWrite(23, HIGH);
                                    delay(1000);
                                    digitalWrite(23, LOW);
                                    delay(1000);
                                }
                            

Sample code borrowed from Revishankar (FA25) Code not working with INMP441, maybe because of previous unintented disassembly of components

Error: Serial Monitor howed an error and serial plotter showed continuous lines with no variation. Was solved when sliding the switch in my programmer board

When I ran the code again I faced this error

turns out it was due to me not inputting the right pin numbers for SCL, SD, WS

Now I wanted to make the on-board LED to light up if the noise captured by microphone increases above 1000

Error: I also faced errors with While loops. Taking out the digitalWrite statement also did not work

This was solved by adding the pinMode statement in void setup

                                
    #include <Arduino.h>
    #include <driver/i2s.h>
    
    #define I2S_WS  12
    #define I2S_SCK 27
    #define I2S_SD  2
    #define LED 23 
    
    void i2s_setup() {
        i2s_config_t i2s_config = {
            .mode = (i2s_mode_t)(I2S_MODE_MASTER | I2S_MODE_RX),
            .sample_rate = 16000,
            .bits_per_sample = I2S_BITS_PER_SAMPLE_32BIT,
            .channel_format = I2S_CHANNEL_FMT_ONLY_LEFT,
            .communication_format = I2S_COMM_FORMAT_I2S_MSB,
            .intr_alloc_flags = ESP_INTR_FLAG_LEVEL1,
            .dma_buf_count = 8,
            .dma_buf_len = 1024,
            .use_apll = false,
            .tx_desc_auto_clear = false,
            .fixed_mclk = 0
        };
    
        i2s_pin_config_t pin_config = {
            .bck_io_num = I2S_SCK,
            .ws_io_num = I2S_WS,
            .data_out_num = I2S_PIN_NO_CHANGE,
            .data_in_num = I2S_SD
        };
    
        i2s_driver_install(I2S_NUM_0, &i2s_config, 0, NULL);
        i2s_set_pin(I2S_NUM_0, &pin_config);
    }
    
    void setup() {
        Serial.begin(115200);
        i2s_setup();
        Serial.println("INMP441 Microphone Test Started...");
        pinMode(LED, OUTPUT);
    }
    
    void loop() {
        int32_t sampleBuffer[1024];
        size_t bytesRead;
        
        i2s_read(I2S_NUM_0, sampleBuffer, sizeof(sampleBuffer), &bytesRead, portMAX_DELAY);
        
        int numSamples = bytesRead / sizeof(int32_t);
        int32_t sum = 0;
        
        for (int i = 0; i < numSamples; i++) {
            sum += abs(sampleBuffer[i] >> 14);
        }
        
        int averageAmplitude = sum / numSamples;
    
        if (averageAmplitude>900){
            digitalWrite (LED, HIGH);
            delay(500);
        }
        else{
            digitalWrite(LED, LOW);
        }
    
        
        // Serial.print("Amplitude: ");
        Serial.println(averageAmplitude);
        
        delay(100);
    }
                            

Now to add voice commands I use this youtube video

Once you clone both repos, To open a folder in VS Code folder, go to the file directory and type code .

But I was unable to access the required file, so I used Chat GPT

Quick Start with ESP-Skainet for Generic ESP32-S3 DevKit-C

Pre-requisite:
Now this project runs on IDF version 5.x.

ESP-Skainet:
Make sure you have cloned my project branch with the '--branch'. Also, need to get all submodules so don't forget the option '--recursive'.

    git clone --branch ESP32-S3-Devkit-C --recursive git@github.com:0015/esp-skainet.git

Example that can be operated in ESP32-DevKit-C and INMP441

Set your I2S microphone settings

    cd esp-skainet/components/hardware_driver/boards/include

Open the file, 'esp32_s3_devkit_c.h'

    #define FUNC_I2S_EN (1)
    #define GPIO_I2S_LRCK (GPIO_NUM_11)
    #define GPIO_I2S_MCLK (GPIO_NUM_NC)
    #define GPIO_I2S_SCLK (GPIO_NUM_12)
    #define GPIO_I2S_SDIN (GPIO_NUM_10)
    #define GPIO_I2S_DOUT (GPIO_NUM_NC)
                

git clone --branch ESP32-S3-Devkit-C --recursive git@github.com:0015/esp-skainet.git
                

cd esp-skainet
git submodule update --init --recursive
                

ls esp-skainet/components/hardware_driver/boards/include/
                

git branch
                

git checkout ESP32-S3-Devkit-C
git pull origin ESP32-S3-Devkit-C
                

rm -rf esp-skainet
git clone --branch ESP32-S3-Devkit-C --recursive git@github.com:0015/esp-skainet.git
                

git log -- components/hardware_driver/boards/include/
                

So the solution that worked for us, was the following:

                    git branch
                    git checkout ESP32-S3-Devkit-C
                    cd esp-skainet
                    git submodule update --init --recursive
                

Modified .h file as such

But this error showed