Archive for "Jan 2017"

How to Run a Server from VMware Client

I’m running some server software in a virtual machine running Debian 8 which is running under VMware on a Windows 8.1 host. While it’s easy to access the server through VMware’s virtual NAT from the host computer, it isn’t at all clear how to access it from outside the Windows host. There are two ways to […]

Precision PWM Frequency for Arduino / ATmega 328P

I’m working on an application where I need fine adjustment of PWM frequency. The existing PWM code that I found, such as the Arduino PWM Frequency Library, only allows integral frequencies to be selected. On pins supported by 16-bit timers, the Arduino PWM Frequency Library allows fine adjustment of duty cycle, but not frequency. After […]

How to Dramatically Speed Up AVRDUDE with USBasp or USBtinyISP Programmers

AVRDUDE has a little-known command line parameter, -B, which sets the bitclock, and can dramatically speed up writing/reading firmware to/from an AVR MCU when using a USBasp or USBtinyISP. For a USBasp, simply add -B0.5 to your command line parameters. Example: avrdude -cusbasp -B0.5 -pm3280 -U flash:w:firmware.hex In my tests, adding -B0.5 reduces the time to write […]

WS2812B LED (NeoPixel) Control: Part 2 – WiFi Control via Art-Net on ESP8266

INTRODUCTION For wireless control of WS2812B (NeoPixel) LEDs, I initially played with Bluetooth SPP (Serial Port Profile), due to the simplicity of setting up the host software… from the host’s software’s point of view, the connection just looks like a physical serial port. Unfortunately, the flakiness of my Windows 8.1 PCs’ Bluetooth SPP support caused me […]

WS2812B LED (NeoPixel) Control: Part 1 – Serial Control via 8-bit ATmega (Arduino)

INTRODUCTION I’ve been laying the groundwork for doing some projects using remote controlled RGB LEDs. My first attempt was Lampduino, which used discrete RGB LEDs, and an ITEAD Colorduino as a controller. In that project, I ran into several pitfalls: though inexpensive, assembly of the LED matrix was very labor intensive the LED’s were rather dim, […]