Audio Hacking With The ESP8266

If you study the specifications of the ESP8266 WiFi-enabled microcontroller, you will notice that it features an I2S audio interface. This is a high-speed serial port designed to deliver 16-bit audio data in a standard format, and has its origins in consumer audio products such as CD players. It would be usual to attach a dedicated DAC to an I2S interface to produce audio, but [Jan Ostman]’s synthesiser projects eschew that approach, and instead do the job in software. His I2S interface pushes out a pulse density modulated data stream in the same manner as a 1-bit DAC, meaning that the only external components required to produce audio are a simple low-pass filter. He’s posted a video of the synth in action, which we’ve placed below the break.

The example he gives us is a basic clone of a Roland 909 drum machine, and he takes us through the code with extensive examples including MIDI. He’s using the Wemos D1 Mini board, but the same could be replicated with many other ESP8266 platforms.

We’ve featured [Jan]’s work many times before, from his minimalist Atmel-based devices through to small but perfectly-formed complete instruments.

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IoT Chore Reminder for the Serially Forgetful

The secret to domestic bliss often lies in attention to detail, an area in which we can all do a little better. But if paper notes and smartphone reminders are not enough to help you remember to knock jobs off your list, perhaps this IoT task reminder will give you the edge you need to keep the peace at home.

As [Andreas Spiess] points out, his best intentions of scheduling recurring tasks in Google Calendar were not enough to keep him on on top of his share of chores around the house. He found that the notifications popping up on his phone were far too easy to swipe away in favor of other distractions, so he set about building a real-world reminder. His solution uses a WeMOS D1 Mini in a bright blue 3D-printed box with from one to four LED switches on the front. Each box is linked to his Google Calendar, and when a task comes due, its light turns on. Sprinkled about the house near the task, like the laundry room or near the recycling, [Andreas] can’t help but see the reminder, which only goes out when he cancels it by pressing the task button. Simple but effective, and full of potential for other uses too.

Of course, the same thing could be accomplished with a Magic Mirror build, which we’ve seen a lot of over the years. But there’s something about the simplicity of these devices and their proximity to the task that makes sense — sort of like the Amazon Dash concept. We might build a few of these too.

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Router Rebooter Eliminates Hassles

Some low-end or older routers might get you a decent WiFi network in your house or apartment, but often these cheaply made devices are plagued with subtle software problems that cause the router itself to become unresponsive after a few days of operating. One solution is to just power cycle the router by hand whenever the Internet disappears, but a better solution is to build something that does that for you.

[Charlie] had this problem as the de facto IT person in his family, and didn’t want to keep getting bothered for such a simple problem. His solution involves a relay, an ESP8266, and a Wemos D1 mini. The device connects to the Internet through the router and occasionally sends out pings to another address. If it can’t ping the address successfully after a certain time period, the device power cycles the router by activating the relay.

Since this isn’t the newest idea out there, there are many ways to solve this problem if you are constantly annoyed by router issues, whether from your own router or from friends and family who treat you as their personal IT department. One solution doesn’t involve any extra hardware at all as long as you have a computer near your router/modem already, and others solve this problem when it happens to the modem rather than the router.

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