What could be the underlying causes of the error message ‘i2c3::_checkBusStatus SCL is stuck low; last write status 00010110’?

In my experience, resolving ‘i2c3::_checkBusStatus SCL is stuck low; last write status 00010110’ often requires some creative debugging. Here are some unconventional methods I have used:

1. Software Reset of I2C Bus: Write a routine to reset the I2C bus via software, which includes sending multiple clock pulses on the SCL line to clear any potential clogs in communication.
2. Logic Analyzer: Use a logic analyzer to capture the I2C transactions. This can give insight into the exact sequence of events leading up to the error.
3. Check for Short Circuits: Using a multimeter, test the resistance between the SCL line and ground. A low resistance might indicate a short circuit somewhere on the board which could be pulling the line low.
4. Firmware Update: Verify if there are any firmware updates available for the I2C devices. Sometimes, a firmware bug can cause unexpected behavior on the bus.

To address the error ‘i2c3::_checkBusStatus SCL is stuck low; last write status 00010110’, I would start by examining the physical connections. Here are the steps I would follow:

1. Inspect the Wiring: Ensure that there are no loose or broken connections in the I2C bus. This includes checking the wires connected to the SCL and SDA lines to ensure they are securely connected.
2. Check Pull-Up Resistors: Validate the presence and the correct value of pull-up resistors on the SCL and SDA lines. Typically, 4.7kΩ resistors are used, but this can vary based on specific requirements.
3. Test I2C Devices: Verify the functionality of all I2C devices connected to the bus by isolating each one. Disconnect the devices one by one and check if the SCL line becomes free.
4. Examine Power Supply: Confirm that all I2C devices are receiving the proper voltage levels. Under-voltage can sometimes cause devices to malfunction, holding the SCL line low.

When I encountered the error ‘i2c3::_checkBusStatus SCL is stuck low; last write status 00010110’, the first thing I did was to look into possible software-related issues. Here’s my software debugging approach:

1. Initialize I2C Bus Properly: Ensure that the microcontroller or processor properly initializes the I2C peripherals. Incorrect initialization sequences can lead to bus contention.
2. Implement Error Handling: Incorporate robust error handling in your code to reset the I2C bus in case of errors. This might include sending a series of clock pulses manually to reset the bus.
3. Check Device Addresses: Ensure that no two devices share the same I2C address. Address conflicts can cause one device to hold the SCL line low while the other tries to communicate.
4. Review Clock Stretching: Some I2C devices require clock stretching to signal that they are not ready to proceed with a data transfer. Ensure your master allows for clock stretching.

From my experience dealing with ‘i2c3::_checkBusStatus SCL is stuck low; last write status 00010110’, I’ve found the following environmental and setup-related causes to be common culprits:

1. Electromagnetic Interference (EMI): Electromagnetic interference can sometimes cause intermittent issues with the I2C bus. Using shielded cables or improving the grounding can help mitigate EMI.
2. Board Layout: A poor PCB layout with long I2C traces can increase susceptibility to noise. It’s crucial to keep the SDA and SCL lines short and run them close together with a solid ground plane beneath them.
3. Testing with a Known Good Setup: Compare your setup with a known good setup to identify any discrepancies. For instance, test with a different microcontroller or a different I2C device to isolate the problem.