This is the second entry into the tutorial series centered around the MakerBLE Arduino board. Using the BLExAR iOS app again, we are able to monitor the incoming data from the MakerBLE board, plot the values, and save them to a comma-separated value (CSV) file. The data being sent is read from a BMP280 sensor over the I2C port by the MakerBLE board. Temperature, atmospheric pressure, and approximate altitude were all sent over the BLE connection with an iPhone.

The MakerBLE is introduced as a miniature breakout board variation of the nRF52840 Bluetooth Low Energy (BLE) Arduino board, which is capable of communicating with smartphnoes and carrying out many of the capabilities of other wirelessly-enabled microcontrollers. The MakerBLE is also compatible with our iOS app, BLExAR, and allows users to collect data, send commands, and control pins remotely from a smartphone. In this tutorial, the MakerBLE will be introduced and its capabilities will be explored from the perspective of the Arduino. This will also be the first in a series of entries geared toward low-power, BLE-enabled, tiny microcontroller projects; whether they involve remote control, data collection from sensors (I2C, SPI, UART), message transfers, BLE peripheral/central communication, or general electronics testing.

In this tutorial, a 1.54 inch e-Paper module is wired to a BLE-Nano Arduino board to communicates via SPI and display text in real time over Bluetooth. The e-Paper module here can be powered via 3.3V or 5.0V, requires very low power when refreshing (2mA-8mA), and can be completely powered off while retaining its text. An Android smartphone and the BLExAR app will be used to print text on the e-Paper display in real time, demonstrating the capabilities of electronic paper technology.

The TinyBlueX is a Bluetooth Low Energy-enabled microcontroller module that combines an ATtiny85 microcontroller and CC254x Bluetooth Low Energy chip. The TinyBlueX is compatible with the Arduino platform (IDE) and the BLExAR iOS Arduino app. The TinyBlueX is very low power and has a low profile, which makes it great for very low power internet of things (IoT) applications with analog and digital sensors. The TinyBlueX can read sensors and transmit the data back to an iOS device, while also being able to read iOS commands and control LEDs, indicators, and motors. Pins 2,3,7 are available on the ATtiny85 aboard the TinyBlueX, allowing users to control/read up to 3 different devices or sensors. In this tutorial series, the TinyBlueX will be explored by instructing users on how to upload code to the module, how to control LEDs, and how to send data back to an iOS device using the BLExAR app.

The INMP441 MEMS microphone is used to record audio using a Raspberry Pi board through the inter-IC sound (I2S or I2S) bus. The I2S standard uses three wires to record data, keep track of timing (clock), and determine whether an input/output is in the left channel or right channel. First, the Raspberry Pi (RPi) needs to be prepped for I2S communication by creating/enabling an audio port in the RPi OS system. This audio port will then be used to communicate with MEMS microphones and consequently record stereo audio (one left channel, one right channel). Python iS then used to record the 2-channel audio via the pyaudio Python audio library. Finally, the audio data will be visualized and analyzed in Python with simple digital signal processing methods that include Fast Fourier Transforms (FFTs), noise subtraction, and frequency spectrum peak detection.

The BLE Nano is introduced as a hybrid between an Arduino Nano and a CC2540 Bluetooth Low Energy (BLE) module. The Arduino Nano has an ATmega328P as its main microprocessor, which communicates over the serial port to send and receive Bluetooth packets from the CC2540 BLE chip. This creates a Bluetooth-enabled Arduino device - encased in a Nano-sized circuit board! Using the BLExAR iOS app, the BLE-Nano will be controlled using an iPhone. BLExAR allows users to control the pins on the Nano, which will be demonstrated by switching an RGB LED on and off.

In this tutorial, the ATtiny85 is reintroduced, this time as a Bluetooth-enabled device. First, some of the basics of burning the bootloader to the ATtiny85 and using the Arduino board as an in-system programmer (ISP) are explored. Then, a CC2541 Bluetooth Low Energy (BLE) module is used to communicate with an iOS device using the BLExAR app. Lastly, temperature and humidity data is read by the ATtiny85 and transmitted via Bluetooth to the smartphone.

In this tutorial, I will dive into the variations of CC2541 BLE board such as the AT-09, MLT-BT05, HM-10, JDY-08, etc. I will use either the specific module name or a blanketed “CC2541-based module” reference to refer to the BLE modules. The general process for interfacing with each module is nearly the same, however, some particularities define how each responds and functions depending on the given firmware. I will also be using the BLExAR app for iOS to communicate with the CC2541 modules.

The MPU6050 is a 6-DoF (degree of freedom) accelerometer and gyroscope that is designed for inexpensive, small-scale, and efficient approximation of motion. Accelerometers and gyroscopes are used in smart phones for orientation detection, vibration analysis in vehicles and machines, and even camera stabilization and motion tracking. There are countless applications for accelerometers and gyroscopes, and with devices as accessible as the MPU6050, we can really test the limits of the technology.

In this tutorial, I introduce an Arduino-based weighing scale that uses a load cell, analog-to-digital converter, and calibrated mass. I introduce calibration with known masses to create a powerful and accurate weighing system that can be used for highly accurate measurement purpose such as: chemistry, horticulture, cooking, and much more!

The BLExAR app will be used in conjunction with a CC2541 (HM-10, JDY-08, AT-09, SH-M08) Bluetooth module and an Arduino (ATmega328) board to create a simple data acquisition system. A DHT22 sensor will provide temperature and humidity data to the Arduino which will be recorded by an iOS device via the BLExAR app. This experiment is a real-world example of an Arduino application demonstrating data acquisition from a real sensor. This tutorial will allow users to solve their own engineering problems using the modern Arduino platform and wireless communication through the BLExAr app, which will ultimately expand the reach and compatibility of technology in the classical sciences through exploration and experimentation.

Control an RGB LED using three PWM pins on an Arduino Uno board via Bluetooth communication. An RGB LED is a single casing with three cathode (or anode) pins and one anode (or cathode) pin. This results in a 4-pin LED. In this tutorial, I will be using an RGB LED with three anodes and one common cathode. This means that we can change the color of the LED to over 16.7 million different variations (assuming each anode produces a different luminosity for each voltage change of the Arduino PWM pin). This tutorial will help demonstrate the power of the BLExAR app, and the flexibility of an Arduino board under iOS Bluetooth control. In my case, I will be using an iPhone with the BLExAR app, but an iPad would suffice as well.