Arduino – Processing Laser CNC Project

Neumi @ has build an Arduino based CNC project and source files are provided.

This is my scratch build Laser CNC Engraver and PCB Exposer. It uses a 150mW 405nm laser diode and two CD drive motors and mechanics. A Processing sketch calculates the position of the pixels and send them to an Arduino Mega, wich drives the steppermotors. A TTL driver is used to control the Laser. With the joystick you can control the laser. You can set the exposure time, so you can engrave foam, paper, leather, plastic and wood. If you engrave photo-coated PCBs its possible to harden the surface and create your custom made PCBs.
The resolution is at about 100 pixels/cm. The work area is 3,2 x 3,2 cm.

Arduino – Processing Laser CNC Project – [Link]

Circuit lets you test capacitors for leakage


Raju R Baddi @ has published a circuit that enable you to test electrolytic capacitors and decide if worth using it on a circuit.

The values in the figure are typical for general testing of all capacitors, from 1-nF ceramic versions to 1000-μF electrolytic types. The value of CREF in the circuit is near the value of the test capacitor, CX. You can also choose RREF, by a rotary-switching arrangement, to be greater than or less than 22 MΩ.

Circuit lets you test capacitors for leakage – [Link]

RFM69 to MQTT gateway using ESP8266


Martin @ has published an article on how to forward traffic from RFM69 to MQTT using  ESP8266:

I’ve mentioned my plans for this project during the IoT hangout session few months ago, it has finally materialized as working prototype. The blocker so far was the lack of ESP8266 RFM69 driver and free time on my end, so I’ve teamed up with Andrey Balarev to solve this. Andrey is an IoT enthusiast + embedded systems developer and has done excellent job in porting LowPowerLab’s RFM69 library for the ESP8266.

RFM69 to MQTT gateway using ESP8266 – [Link]

ATTiny25 based tea timer


Michael @ has built the “perfect” tea timer project. He wrote a post on his blog detailing its assembly:

Maybe you just drink coffee. Then this article is not particularly interesting for you. But if you like a cup of black or green tea once in a while you might know the problem: You prepare your tea and you let it stand for a minute too long. Then it is bitter. So the next time you use the timer functionality of your smartphone … unlock the screen, open the timer app, enter something like “3:00″ (minutes), press start, pour boiling water over the tea, wait. Then your phone beeps like crazy while you are fumbling around with the hot and wet teabag you want to dispose of. Finally you unlock your beeping phone with your wet fingers, open the timer app again and silence it. Pure stress.

ATTiny25 based tea timer – [Link]


iBlinds – Make Your Existing Blinds Intelligent


Z-wave Alliance contest winner and Texas-based HAB Home Intelligence has launched a crowdfunding campaign on to bring iBlinds, a DIY home automation kit, to the market.  The product will allow customers to make their existing window blinds “smart” and to control multiple devices with a touch of one button on a phone, tablet, PC or Z-wave remote.

iBlinds is an easy-to-install solution for homeowners looking to automate and control the blinds already in their home.  No need to purchase any special tools, order a new set of blinds or even call a contractor.  The intelligent blind motor will work with any Z-wave controller and app to give homeowners control over their blinds.  Z-wave integration will also enable iBlinds to interact and communicate with other smart home devices on the network, which can be used to create scheduled times to open and close.  Remotely control a single blind or a group of them from anywhere in the house or in the world.

iBlinds – Make Your Existing Blinds Intelligent – [Link]

PULPino – An open-source microcontroller system based on RISC-V


PULPino is an open-source microcontroller system, based on a small 32-bit RISC-V core developed at ETH Zurich. The core has an IPC close to 1, full support for the base integer instruction set (RV32I), compressed instructions (RV32C) and partial support for the multiplication instruction set extension (RV32M). It implements several ISA extensions such as: hardware loops, post-incrementing load and store instructions, ALU and MAC operations, which increase the efficiency of the core in low-power signal processing applications.

PULPino – An open-source microcontroller system based on RISC-V  – [Link]

Time-based One-time Password fob for Google Authenticator

espruino_otp has coded an Espruino Pico to work like a HID device.

Now that the Espruino Pico has (beta) HID support, it can pretend to be a keyboard or mouse (or other HID compatible device). This makes it possible to send characters to the active window on your Windows/Linux/Mac PC. I’ve cobbled together some code which turns the Pico into a device like a YubiKey. Press the button and get the latest auth code pasted automatically for you.

Time-based One-time Password fob for Google Authenticator – [Link]

Bubble display shield for Adafruit Trinket


davedarko created this Adafruit Trinket Pro shield for the HP QDSP-6064 bubble display. The design files and source code are hosted on GitHub.

An additional temperature sensor in the form of the LM75 can be added to this bubble display shield. The atmega32p is capable of driving up to 40mA per pin, so with the display needing 5mA per element of a digit, it should be fine, since it will be a pulsed signal and there are 8 elements max.

Bubble display shield for Adafruit Trinket – [Link]

ESP8266 + DS18B20 to Emoncms

Jhon_Control @ has written a tutorial on how to monitor temperature using the ESP8266 and DS18B20 and display the data on Emoncms platform.  Emoncms is an open source web application that enable you to monitor and visualize different environmental data.

ESP8266 + DS18B20 to Emoncms – [Link]