The ESP32 has a built-in 8-bit DAC. Digital to the analogue signal converter or analogue-digital converter or DAC is a device to convert digital signals with binary data into current or analogue voltage signals. For better sound quality, we can use an external I2S codec and amp. Adafruit I2S amp uses a MAX98357A IC. The MAX98357 is a low-cost, digital pulse-code modulation (PCM) input amplifier. … [Read more...]
Hardware
Detailed article on computer hardware parts like RAM, Motherboard, Processor, Graphics card. Hardware also covers topics on hardware of Server, Single Board Computers like Raspberry Pi to Libre Hardware Projects.
Reusing the Technologies of Latest Vaping Devices
The goal of this article is to discuss the art of engineering employed in various mods which may be employed in other devices of day to day usage. Vaping can be illegal or restricted in certain countries. Purpose of this article is not to encourage breaking the laws. For developmental purpose, first, we need to briefly discuss the construction of an e-cigarette. Table of Contents 1 … [Read more...]
Note on Calculating Distance From RSSI Value of BLE Devices
A quick question from one reader after publication of Smartwatch BLE to Trigger IBM Watson IoT Event was "can I measure the distance in meters and broadcast?". The answer is - it is not reliable with easy formula against a single BLE device. If we were using Raspberry Pi, then we could think of using complex coding. BLE technology and works with Indoor Location Positioning is not new. RSSI … [Read more...]
Detect Samsung Smartwatch BLE and Trigger IBM Watson IoT Event
We can trigger ESP32 to send message to IBM Watson IoT in Presence of a Particular Samsung Galaxy Smartwatch. This involves BLE and WiFi. In our one series of articles on Samsung Smartwatch as Proximity Switch, we triggered a local event, such as control of a relay. In our other series of articles, we sent message to IBM Watson IoT with upon pressing a button (this guide and this guide). Now, … [Read more...]
Solve ESP32 Sketch Too Big Error on Arduino IDE
Sketch too big is a common issue faced inside Arduino IDE while working with BLE. Most of us set up the Arduino IDE for ESP32 and forget to alter any other settings of the IDE because except some situations, we never face this problem. The error will suggest you navigate to this official webpage of Arduino (which is not exactly related to ESP32), which will tell you … [Read more...]
Samsung Smartwatch as Proximity Switch : Part V [END]
This is the final part of the series. In Part I, we talked about the basics which continued to Part II. Part III had a working code non-specific to any particular device. Part IV had a partially working code specific to a particular device. circuitdigest.com's code (in Part IV) was not working with Samsung Galaxy Watch LTE. Samsung's smartwatches shutdown both BLE and traditional … [Read more...]
ESP32 BLE Server with Android App
BLE only works when one communication is active and stays ON. Else it remains in sleep mode. Beacons are great usage of BLE. In our series of articles on Samsung Smartwatch as Proximity Switch, we have used the ESP32 as client. In this article, we are talking about using ESP32 BLE as a server. In our series of articles on Samsung Smartwatch as Proximity Switch, we discussed GATT Service and BLE … [Read more...]
Can We Reprogram a Musical Greeting Card Circuit?
The easy time-saving answer is "do not try". All of them are cheap. The original "chip corders" were developed by Richard Simko, sold by ISD could record 20 seconds of the analogue signal. Later, Nuvoton acquired ISD and developed for longer record times at relatively inexpensive end cost. A web search with the phrase "Chip Corder" should give you plenty of examples of the chips. If there is a … [Read more...]
Galaxy Watch LTE Versus Active 2 LTE
They are not comparable as watches. They can be compared only for the specification part. These two watches are different for their look, not exactly they are too different from the specification point of view. May be, Samsung wanted two watches, one with a masculine sports design and another with a normal watch look. Over 5 years, smartwatches evolved in design and in the functionalities they … [Read more...]
Samsung Smartwatch as Proximity Switch : Part IV
In the previous part of this topic (here is part III), we provided a sample code to create a basic BLE scanner. The code makes the ESP32's on-board LED to turn on whenever the watch comes in proximity. In our earlier parts of this series, we talked about filtering the MAC address and practical matters around Samsung Galaxy Watch. I found that the website circuitdigest.com worked with a similar … [Read more...]
Samsung Smartwatch as Proximity Switch : Part III
Instead of publishing a single article on a complex matter, we split into parts. This methodology makes the thing boring to the initial readers but in the long term, the readers can browse our website and fix themselves. In the previous two parts of this topic (here is part I and here is part II), we created the base with theory and practical so that even an unused reader does not get confused or … [Read more...]