BLE Wireless Heart Rate Collector

Wanting to learn more about creating embedded Bluetooth Low Energy (BLE) firmware, I recently purchased a Nordic nRF52840 dev kit shown below.

Nordic nRF52840 DK Development Kit

I also purchased an inexpensive BLE heart rate monitor and a small OLED display from Adafruit to use with the nRF52840 to display realtime data from the hea…

Date: August 31st, 2019 at 4:24pm
Author: Terence Darwen
Tags: Embedded, BLE, Bluetooth Low Energy, Heart Rate Collector, Heart Rate Monitor, Nordic, nRF52840-DK, ARM Cortex-M4, SSD1306

Interfacing a MIDI Keyboard with a Tiva LaunchPad (ARM Cortex-M4 Processor)

I've managed to interface a typical MIDI keyboard controller (an M-Audio Oxygen 61) with my Texas Instruments Tiva LaunchPad (ARM Cortex-M4) development board as shown below.

MIDI Keyboard, Tiva LaunchPad and Circuit

By doing some Googling I found out that the MIDI protocol is a typical UART connection running at a baud rate of 31,250. Th…

Date: April 26th, 2017 at 4:24pm
Author: Terence Darwen
Tags: Embedded, Tiva LaunchPad, TM4C123G, ARM Cortex-M4, Synth Project, MIDI Keyboard

Using Dual MCP23S17 I/O Expander Chips with the Tiva LaunchPad

In a post a few weeks ago I showed how I had been using an I/O expander chip with the Texas Instruments Tiva LaunchPad to provide eight additional inputs using a single serial connection. I've managed to increase this to 32 inputs.

Tiva LaunchPad and Dual MCP23S17 Chips Annotated

I did this by using dual MCP23S17 I/O expander chips as shown in t…

Date: March 1st, 2017 at 8:43pm
Author: Terence Darwen
Tags: Embedded, Tiva LaunchPad, TM4C123G, ARM Cortex-M4, Microchip MCP23S17, I/O Expander, Synth Project