/r/diyelectronics on Reddit currently has two electronics design contests going on:
Deadline is April 3rd for this beginner contest
The mission here is simple: give me a clock you won’t see in a store.
Perhaps a word clock. A lava lamp water clock. An alarm clock that slaps you in the face and eats your hair (warning: audio). I don’t care.
Deadline is April 30th for this advanced contetst
The goal is to build a switching buck DC-DC converter from discrete components that can step down a fairly common input voltage to another common output voltage–in this case, 3.3V.
We are big fans of Joe Grand! You may know him from his awesome designs like Emic 2 Text-to-Speech, Defcon badges, JTAGulator and many more on Grand Idea Studio. We loved watching Joe introduce cable TV audiences to hardware hacking on the Discovery Channel show Prototype This!
Here’s a fun project from Joe Grand that he has shared on OSH Park:
The Creaturepod is a portable walkie talkie system that enhances children’s interactive play. It mimics the fictional Creaturepod from the popular children’s television show, Wild Kratts.
Joe writes: “The design features an Arduino Mini Pro 328, 2.2-inch TFT liquid crystal display (LCD), DRA818U voice transceiver module, electret condenser microphone, speaker, and buttons for channel/ frequency selection and push-to-talk capability. Bitmap images are stored on a microSD card and displayed on the LCD to indicate the currently selected channel. A 2000mAh Lithium-Polymer battery provides more than 20 hours of playtime before recharging is necessary.”
Ronald Sutherland created a PCB with a self portrait on the copper layer:
I guess at some point everyone does this…
Ronald has shared his project on OSH Park:
2 layer board of 1.86×2.36 inches (47.14×59.87 mm).
Shared on January 30th, 2015 21:48.
Michael O’Brien created this project to monitor automotive performance:
Michael wrote about his experiments with plated slots in his hackaday.io project log:
NOTE: Internal Cutouts and Slots
We officially support non-plated slots and cutouts that are at least 100 mil wide (0.1inches / 2.54mm).
Whenever possible in your designs, we advise replacing small or plated slots with a large via. Typically, setting the hole size equal to the slot length is sufficient to fully replace the feature with minimal design impact.
davedarko wanted an easy way to check a USB cable, so he created this project on hackaday.io:
Test your mini, micro and A-A cables with this little device!
A little ATtiny45, some LEDs and transistors – battery powered. It scans through the cable with some blinking LEDs, then goes to sleep.
The design files and source code are shared on GitHub:
And the board is a shared project on OSH Park:
Reinier van der Lee created the Vinduino project (Vineyard + Arduino) to better manage the irrigation of his Southern California vineyard:
Monitoring soil moisture at different depths to determine when to irrigate, and – more importantly – how much water is needed. Save 25%!
Reineir explains further on his project page:
If you want to learn about saving water, talk to a farmer. California farmers, including myself, voluntarily aim to reduce agricultural water consumption by 25%. This reduction is more than the annual urban water use, much more effective than any residential water reduction can achieve.
The project includes:
- DIY calibrated gypsum soil moisture sensors
- Hand held sensor reader for soil moisture, salinity & water pressure
- Solar powered remote sensor platform:
- 3 electrically separated inputs for soil moisture sensors
- Wifi (ESP8266) or Appcon RF module for long range connectivity (miles)
- Irrigation valve control, optional pressure sensor for valve operation feedback
- DHT-11 temperature/humidity sensor
Vinduino has produced impressive results:
- In 2015 we saved 25% , or 430,000 gallons, of irrigation water.
- Cost saving on water and labor was $1,925
- Cost to achieve these savings was $635
- Minimum configuration for developing countries, incl. salinity measurement: $60
ReiniervdL has shared two project on OSH Park:
2 layer board of 3.69×3.15 inches (93.65×80.01 mm).
Shared on June 7th, 2015 21:33.
2 layer board of 2.39×2.00 inches (60.66×50.80 mm).
Shared on June 7th, 2015 21:33.
This UV monitor on hackaday.io was designed to help prevent UV-caused skin damage:
This is a UV monitor based around the SI1132 light sensor and an ATMEGA168. It uses a sound-based interface, where beeps signal settings for skin type and use of sunscreen, if any. This is to save the power and cost of a display, and also in recognition that the device will be used outdoors in bright sunlight, where only reflective displays would be usable.
SI1132 was chosen as it produces a ‘calibrated’ UV index and takes up very little space. ATMEGA168 was chosen as a cheap uC with hardware I2C support which is supported by the Arduino environment (to allow a broad range of users to easily modify the code as they see fit).
The design files and source code are hosted on GitHub:
matrixwide shared the board design on OSH Park: