Ashish Derhgawen built a coherer-based receiver with a simple decoherer mechanism, and connected it to a Beaglebone to decode the received signals:
In my last post, I described how I made a spark-gap transmitter and receiver. For the transmitter, I used a car’s ignition coil to produce high voltage sparks, and for the receiver, I used a coherer to detect the transmissions. A coherer is a simple device – it consists of iron filings between two electrodes. Normally the filings have very high electrical resistance (tens of megaohms), but when the coherer detects electromagnetic waves, its resistance drops to about 10-20 ohms.
I’m using the tiny and inexpensive Nordic Semiconductor nRF24L01+ transceiver (see “Tutorial: Nordic Semiconductor nRF24L01+ with the Freescale FRDM-K64F Board“) in many projects: it costs less than $3 and allows me to communicate with a proprietary 2.4GHz protocol in a low power way (see “IoT: FreeRTOS Down to the Micro Amps“). I have that transceiver now running with the tinyK20 board too.
Ray Wang has published a new project called OpenGarage, an open-source garage door opener based on ESP8266 and the Blynk app:
Today I am very excited to introduce you to OpenGarage — an open-source, universal garage door opener built using the ESP8266 WiFi chip and the Blynk app. I’ve wanted to finish this project for a while, as there have been multiple occasions where I left the house in a hurry and forgot to close my garage door, or locked myself out of the house, or had to let a friend or handyman in while I was away. Having a WiFi-based garage door opener (which I can access remotely using my mobile phone) would be super convenient. Recently as I started learning about ESP8266, I found it to be the perfect platform to help me complete this project.
I’ve been trying to start a SID project for about 5 years now. Back then I wanted to use a 6502 along with a CPLD and other ‘real’ hardware… while I might still do something like that (or even try to use an FPGA for everything except the SID), I think it’s probably good that I waited so long because now this great cheap ESP8266 wireless SoC is around.
Johan Kanflo designed a Esparducam board and built a low cost wifi camera with an Arducam Mini and a ESP8266 Wifi module:
Sometime ago I came across the Arducam Mini which is quite a nice camera module from UCTronics. It is a small PCB with a two megapixel OmniVision OV2640 sensor, an interchangeable lens and an FPGA to do the heavy lifting of image processing and JPEG encoding. Priced at around 24 Euros (lens included) you can easily buy a few without hurting your wallet and combined with an ESP8266 you can build quite a low cost wifi camera. Or several. Because designing and building PCBs is both fun and inexpensive I designed a board to go with the ESP8266/Arducam Mini combo, aptly named the Esparducam. And uniquely named too, try googeling for “esparducam“. Heck, even the domain name is available at the time of writing :)
Rui Santos writes, “In this project we are going to establish a wireless communication between two ESPs and send data from three sensors to an Excel spreadsheet. This tutorial shows a wireless weather station with data logging that you can implement in your home.”