Week 9: Input Devices

The equivalent series resistance (ESR) of a 100 µF, 50 V, X7R multilayer ceramic capacitor (MLCC) in a 1206 package is not typically specified by generic manufacturers. However, based on available data and typical characteristics of similar capacitors, the ESR is generally in the range of 10 to 15 milliohms (mΩ). For example, discussions among electronics professionals suggest that a typical 10 µF, 50 V, X7R capacitor in a 1206 package has an ESR around 10 to 15 mΩ.

Given that ESR tends to decrease with increasing capacitance, it is reasonable to infer that a 100 µF capacitor of the same specifications would have an ESR at or slightly below this range.

For precise ESR values, it is advisable to consult the datasheets of capacitors from reputable manufacturers, as ESR can vary based on specific design and manufacturing processes. Manufacturers like Murata provide tools such as "SimSurfing" that allow users to explore detailed characteristics, including ESR, of their capacitors.

Additionally, KEMET's X7R dielectric capacitors offer detailed specifications in their datasheets, which can be referenced for more accurate information.

Given the lack of specific ESR data for the generic capacitor in question, measuring the ESR using appropriate equipment is recommended for applications where this parameter is critical.

Difference Between I²S and I²C

I²S (Inter-IC Sound)

• Purpose: Used for digital audio transmission.
• Data Transfer: Continuous, synchronized audio data.
• Communication Type: Point-to-point connection.
• Clock Signals: Requires three main lines:
  • Bit Clock (BCLK)
  • Word Select (WS)
  • Data Line (SD)
• Speed: High-speed audio data transfer.
• Applications: Used in DACs, ADCs, and audio codecs.

I²C (Inter-Integrated Circuit)

• Purpose: General-purpose communication between peripherals.
• Data Transfer: Byte-based with master-slave configuration.
• Communication Type: Multi-device bus.
• Clock Signals: Uses two lines:
  • Serial Data Line (SDA)
  • Serial Clock Line (SCL)
• Speed: Typically lower than I²S (up to 1 MHz).
• Applications: Used in sensors, EEPROMs, and RTCs.

Key Differences

Separate Pin Requirements for SDA and SD

Yes! They serve different purposes:

Conclusion

You cannot share the SDA pin from I²C with the SD pin from I²S because they operate on different protocols and electrical requirements. Each must be wired separately to avoid conflicts.

No, the SCK and I2S0_CLK pins are not the same in the INMP441 microphone. Here's how they differ:

1. SCK (Serial Clock)

• This is the I²S Bit Clock (BCLK).
• It is used to synchronize the data transfer between the microphone and the I²S receiver.

2. I2S0_CLK (Master Clock, MCLK)

• The INMP441 does not require an external master clock (MCLK).
• Some I²S devices need MCLK, but the INMP441 operates without it.

Pin Configuration of INMP441:

• L/R: Left/Right channel selection.
• VDD: Power supply.
• GND: Ground.
• SD (Serial Data): Output data line.
• WS (Word Select, aka LRCLK): Left/Right channel selection clock.
• SCK (Serial Clock, aka BCLK): Bit clock.

Since the INMP441 does not use an external MCLK, some microcontrollers might still have an I2S0_CLK pin for providing a master clock for other I²S devices. However, this is not connected to the INMP441.

Let me know if you need more details! 🚀

Step 1: Install Arduino IDE

Download and install the latest version of Arduino IDE.

Step 2: Install ESP32 Board in Arduino IDE

1. Open Arduino IDE.
2. Go to File > Preferences (Windows) or Arduino > Preferences (Mac).
3. In "Additional Board Manager URLs", add:

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

Click OK and close Preferences.

Step 3: Install ESP32 Board Package

1. Go to Tools > Board > Boards Manager.
2. Search for "ESP32".
3. Install "esp32 by Espressif Systems".

Step 4: Install USB-to-Serial Drivers (If Needed)

• CP210x (Silicon Labs)
• CH340G (WCH)

Step 5: Select the ESP32 Board

1. Go to Tools > Board and select "ESP32 Dev Module".
2. Go to Tools > Port and select the ESP32's port.

Step 6: Test with a Simple Sketch

Upload the following Blink sketch:

                        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);
                        }

Click "Upload" and press the BOOT button if needed.

Step 7: Open Serial Monitor

1. Go to Tools > Serial Monitor.
2. Set baud rate to 115200.
3. Verify the Blink program is running.

✅ You're now ready to develop projects with ESP32 on Arduino IDE! 🚀

Possible Reasons & Solutions

1. Repository Not Cloned Properly

Ensure you used the correct branch and included submodules during cloning:

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

If you forgot --recursive, update submodules manually:

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

2. File or Directory is Missing in the Repository

Navigate to the include directory and check if the file exists:

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

3. Wrong Branch or Version

Verify that you are on the correct branch:

                    git branch
                                

If incorrect, switch to the correct branch:

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

4. Corrupt or Incomplete Clone

If the file is still missing, try recloning the repository:

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

5. File Might Have Been Renamed or Moved

Check the repository history for changes:

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

If it was renamed, update your code accordingly.

If you still have trouble, checking the repository’s Issues section or contacting the repository maintainer might help.