Addresses the challenges of structured vs. unstructured data, and introduces the Bag of Words model for feature representation. Explain why each document can be represented as a point in a d-dimensional feature space.

Discusses neural networks, their structure, including input, hidden, and output layers, and the process of weight adjustment using gradient descent. Additionally, this post covers deep learning as a subset of machine learning that utilizes multi-layer neural networks for complex tasks, with a focus on PyTorch for implementation and includes a code example for a simple neural network model.

Explores the Bayes' theorem, which calculates the posterior probability of a hypothesis given evidence. Discusses how the generalized Bayesian model simplifies calculations under the Naive Bayes assumption of independent effects.

Reviews key concepts in probability, including random variables (discrete and continuous), probability distributions (PMF and PDF), expectation and variance, joint distributions, conditional expectation, and complex queries involving random variables.

In projects involving the ESP32, internal flash storage may be insufficient, necessitating the use of a Micro SD card. However, many people encounter SD card instability even when following a guide. This post provides steps to troubleshoot SD card failures, including following instructions, trying different SD cards, checking voltage requirements, measuring voltage with a multimeter, and optimizing power supply connection.

The ESP32 microcontroller has an internal Real-Time Clock (RTC) with limitations in maintaining time during power loss. To overcome this, an external RTC module, such as DS1307, DS3231, can be integrated with the ESP32. This requires wiring the module to the ESP32, using I2C or other interfaces, and optionally connecting a backup battery. Example code is provided for setting up the external RTC and synchronizing with NTP servers for accurate timekeeping in IoT applications.

Today, I published my first YouTube video explaining the system design for my ESP32 data logger project and demoing the React front end for the ESP32. While the video was generally well done, I identified several areas for improvement. Qiwei Mao, Atlanta GA.