WiFi MQTT controlled relay for Home Assistant

I’ve been wanting to use a ESP8266 WiFi module in a project for some time now, and after reading about the WeMos board I figured this was the easiest way to get started. The WeMos D1 mini is quite small, and much easier to interact with and program than the ESP8266 devices. So I built this single relay controller, with internal temperature reporting. I am communicating with it using MQTT, which makes it really easy to implement it into things like Home Assistant.

Read more...

Fan and temperature controller with LCD

The module uses an LM35 sensor for measuring the temperature, it is a pre-calibrated IC with output voltage linearly-proportional to the Centigrade temperature. This is read directly by the internal AVR ADC, and turned into actual degrees with a simple calculation. The fan is powered by an PWM output, giving it variable speed. Set points for the fan and alarm can be adjusted and is saved to EEPROM.

Read more...

Lync presence (busy) light with 5mm LEDs

When I am at work, I use headphones; a lot. About half the time I am listening to music, the other half I am talking with someone on Lync (Skype for Business). This has made it difficult for my colleagues to know whether I am available or not, so I get interrupted when I’m on the phone. I needed a way to communicate my availability, and Lync already does a pretty good job with this; it’s red when I am in a meeting, on the phone or simple do not want to be disturbed. Yellow when I’m away; I don’t think the away part is a problem, when my chair is empty I am usually away… And green: come on in! Enter the Lync presence light, or busy light if you will. Yeah there are some you can buy, but where is the fun in that? So I made one using an Arduino board.

Read more...

Light sensor with LED display

This module measures light intensity and shows it on a scale from 0 to 782 on the LED display. By multiplying that value with 5, and then divide by 127 you get the light intensity in µW/cm2. If the light intensity rises over or falls below (configurable) the set point; the output activates, with a hysteresis of +-25. The module has two outputs; a constant and a pulse. The constant output can be used to drive e.g. a relay, while the pulse can communicate with other equipment. Powered by: 9-24V.

Read more...

Security keypad with programmable PIN

This module uses an AVR microcontroller to interface a cheap numeric keypad. The PIN code is set by the user and stored in EEPROM. If entered correctly; a one second pulse is sent on either output 1 or 2, depending on the selected mode. A tamper pin will be shorted to 0V when the module is connected. This keypad module is not itself meant to control anything, but it provides trigger signals for other control modules to act upon. It has three LEDs (green, red and alarm) which can be used to convey messages from that other control module. Powered by: 5V.

Read more...

Sound alarm control unit

This simple unit controls three sound signals; beep, siren and buzzer. Each sound signal will only be given once when a new alarm is triggered, the input must remain clear for at least four seconds for that signal to rearm. A beep is given every six minutes if an alarm is active, as a reminder. The sound LED flashes when a sound alarm is active; once for signal 1 (beep), twice for signal 2 (siren) and three times for signal 3 (buzzer), this flashing pattern is repeated.

Read more...

Mood light (RBG) with 100 mA outputs

This simple mood light controller has three PWM controlled channels; red, green and blue. Each capable of delivering 100 mA, or about five LEDs. This can easily be improved by using a more powerful transistor. I’ve used 3x3 LEDs soldered to a tiny circuit board as the light source, and placed them inside a frosted glass. A better solution would be to use a powerful RBG LED. Just remember to use another transistor if you want to use bigger LEDs.

Read more...

Emergency strobe light

The emergency strobe light consists of 33 high intensive 5 mm LEDs and control circuit. It has four sequences, and can be set on a single sequence or to cycle through every fifth second. When selecting a sequence manually it is stored in EEPROM and continues on power-up. If an external controlling unit is plugged in; the internal sequences will stop and the external unit is in control. This makes it possible to synchronize multiple units. LEDs are driven by a PWM output, module is powered by 9-24V.

Read more...

Mood light (RGB) controller with 500mA outputs

The mood light controller can control all kinds of RGB light, max 500mA pr. channel. The module has no voltage regulator and therefore needs 5V=, and enough current to drive the circuit and the connected LEDs. It very slowly cycles through different colors, fading one LED up or down leaving the previous LED turned on. The module can power Prolight LEDs, like Mood light using 3W Prolight RGB LED.

Read more...

Lync presence (busy) light with navigation LEDs

This is my second generation Lync light, I built the first one back in May 2016. It worked fine, but it only had three 5 mm LEDs. People who knew about the module noticed, but a lot of people didn’t, so it did not have the effect I was looking for. That’s why I decided upgrade it, and this time use bigger and brighter lights! I found a pair of maritime navigation lights on eBay that were small enough to fit on the top of the enclosure. They are much harder to miss, than the LEDs :) I still use the same Arduino firmware and bridge software as before, just upgraded the hardware.

Read more...

Power supply and fuse monitoring module

This was the first AVR microcontroller module I ever built, it was made for and installed in the rack box project. As the name suggests it monitored that the essentials were OK, that means power supplies, fuses and communication. It used optocouplers to detect if the 5 or 12 V power supply failed, but depended on other modules for the fuse, emergency supply and communication failure.

Read more...

Warning strobe light controller

The warning lights controller has two PWM driven outputs, that each can handle a load of 3 amps. It has five sequences, and can be set on a single sequence or to cycle through. When selecting a sequence manually it is stored in EEPROM and continues on power-up. Much of the hardware and software is based on the Emergency strobe light project. Can be used to drive the Warning lights with 10mm LEDs project. Powered by: 9-24V.

Read more...

Mood light using 3W Prolight RGB LED

This mood light consists of a Prolight RGB 3W LED, a heat sink and four rubber feet. The four rubber feet form a base on which e.g. a glass ball, or something else transparent can be placed. It will be lit up by the LED and looks pretty cool. Powered by: 5V.

Read more...

Warning strobe light controller for car

On my old car, a Subaru Legacy, I built and installed warning lights on all sides. Never really used them, but it was a fun build. I had a total of 8 LED warning lights, all around the car. The lights on the side was used as side markers when not flashing. I originally used the red break light as the rear warning light, but later replaced it with two self-built warning lights.

Read more...

Electronic switch with 4 channels and voltage regulator

I used to have a very small apartment, and in that apartment I made a lot of the LED lights myself. To make it easier to control and power them I also built this electronic light switch. With a voltage regulator, and large heat-sink, it took 9 to 24 volts in; and gave out four channels of 5 volts. I used dual-color red and green LEDs to show the state of each output, and push-buttons to toggle them. After 10 seconds on inactivity the LEDs would turn off. The maximum load pr. channel were 500mA, not a lot but enough to drive some LEDs.

Read more...