ESP32 Wrover - Error when uploading code, no connection to chip. What to do?

michal.zd wrote:

During the ESP32 programming process, error:
File "esptoolutil.py", line 37, in flash_size_bytes
TypeError: argument of type 'NoneType' is not iterable

Preliminary evaluation of available information .

- Analysis of the data provided by the user: .
- User encounters an error while programming the ESP32 module:
.
- Identification of missing information: .
- Exact ESP32 model (e.g. ESP32-WROOM-32, ESP32-C3, etc.).
- Development environment used (Arduino IDE, PlatformIO, ESP-IDF)
- Version of `esptool.py` and Python tool
- Computer operating system (Windows, macOS, Linux)
- Connection configuration details (COM port, connection settings)
- Full content of the error message (whether there is additional information before or after the given line)

Direct answer to question

The error `TypeError: argument of type 'NoneType' is not iterable` in the `esptoolutil.py` file, line 37, indicates a problem with the `esptool.py` utility reading the Flash memory size of the ESP32 module. This may be due to hardware problems, incorrect environment configuration or use of an incompatible module.

Key points: .

- Check the hardware connections and ensure that no additional devices are connected to the module to interfere with communication.
- Make sure you are using the correct ESP32 model with built-in Flash memory.
- Update your development tools, in particular `esptool.py`, to the latest version.

Detailed analysis of the problem .

Possible causes of the error: .

1. Hardware problems:

- Shorts or interference on I/O pins: .
- Connected devices or sensors may interfere with communication with the Flash memory.
- It is recommended to disconnect all additional components and leave only the basic ESP32 connection to the computer.

- Insufficient power supply: .
- The ESP32 may require a stable power supply, especially during programming.
- Make sure the USB port provides sufficient current or use an external power source.

2. Incompatible or faulty ESP32 module: .

- Lack of built-in Flash memory: .
- Some versions of the ESP32-C3 do not have built-in Flash memory and require external SPI Flash memory.
- Check the chip model and its technical specification.

- Physical damage to the module: .
- Physical damage may affect the operation of the Flash memory.
- Check the module for visible damage.

3. Software problems: .

- Updated tools: .
- Older versions of `esptool.py` may not support newer ESP32 models or have known bugs.
- It is recommended to update `esptool.py` to the latest version.

- Incorrect environment configuration: .
- Incorrect settings can lead to problems during programming.
- Ensure that the environment is correctly configured for your module.

Recommended troubleshooting steps:

1. Update tools and drivers: .

- Update `esptool.py`: .
.
- Check Python version: .
- Make sure you are using Python 3.x, as some functions may not work properly in Python 2.x.

2. Verify the ESP32 model: .

- Check module specification: .
- Make sure the module has built-in flash memory.
- If you are using ESP32-C3, make sure it is the version with built-in memory.

3. Check hardware connections: .

- Disconnect all additional devices: .
- During programming, the module should only be connected to the computer.
- Check USB cable: .
- Use a tested USB cable with data transfer function.

4. Configure the development environment: .

- Select the appropriate board model in the IDE: .
- In the Arduino IDE or other environment, set the correct board type and parameters.
- Check Flash memory settings: .
- Manually configure Flash memory size if automatic detection fails.

5. Diagnose the problem via logs: .

- Start tool with enhanced detail option: .
.
- Analyse detailed logs: .
- Additional information may indicate the exact location and cause of the error.

6. Check permissions and access: .

- On Unix/Linux systems: .
- Make sure you have permission to access the serial port.
- You may need to add a user to the `dialout` group or use the `sudo` command.

7. Test on another computer or with another module: .

- Exclude hardware or system problems: .
- If possible, try programming the module on another computer.
- Use another ESP32 module to see if the problem persists.

. News and trends .

- New ESP32 versions and compatibility: .
- New variants of ESP32 modules have recently been released, such as the ESP32-S3, which may require updates to the tools to support them.
- `esptool.py` is updated regularly to support new chips and to fix bugs.

- Increased security and drivers: .
- Some operating systems tighten security policies regarding access to serial ports.
- Driver updates may be necessary, especially on the latest versions of operating systems.

Supporting explanations and details

- Function `flash_size_bytes`: .
- Responsible for reading the size of the Flash memory from the module.
- If it returns `None`, it means that it failed to read this information.

- Error `TypeError` and `NoneType`: .
- Occurs when code attempts to iterate or perform an operation on the value `None`.
- Indicates missing data or an unexpected condition in the program.

Practical tips .

- Regular updates:
- Keep your development tools and drivers in the latest versions.

- Detailed documentation: .
- Refer to the module manufacturer's documentation and development tools.

- Minimise configuration: .
- Maintain a minimal hardware configuration during troubleshooting.

Possible caveats or additional comments .

- Possible faulty module: .
- If all attempts at repair fail, consider the possibility of a faulty ESP32 module.

Suggestions for further research .

- Consult the community: .
- Visit specialist forums such as elektroda.co.uk to search for similar cases.

- Up-to-date resources and documentation: .
- Check out the latest information in the official Espressif documentation and current discussions in the communities.

Short summary .

The error indicates a problem with `esptool.py` reading the size of the Flash memory, which may be caused by hardware problems, incorrect configuration or an incompatible module. It is recommended to run a series of diagnostic steps to identify and resolve the problem.

User queries .

Please answer the following questions to better assist in solving your problem:

1. What exact model of ESP32 module do you have? .
- Is it an ESP32, ESP32-C3, ESP32-S3 or another variant?
- Manufacturer name and possible model number.

2. What development environment are you using? .
- Arduino IDE, PlatformIO, ESP-IDF or other?
- Version of software used.

3. What operating system is installed on your computer?
- Windows (version), macOS, Linux (distribution and version).

4. Can you provide the full error message and the command or actions that lead to the error? .

5. Are there any other devices or modules connected to the module during programming? .

6. Have you tried to program another copy of the ESP32 module, if you have one? .

Obtaining this information will allow you to diagnose more accurately and find an effective solution more quickly.