Voice Controlled Rover Follows Verbal Instructions To Get Around

January 11, 2024 by 3 Comments

Typically, when we want to tell a robot where to go, we either pre-program a route or drive it around with some kind of gamepad or joystick controller. [Robotcus] decided to build a simple robot platform that drove around in response to voice commands instead.

The robot is based around a Raspberry Pi Zero, charged with instructing the motor controllers to drive the ‘bot around. The Pi Zero is also in charge of interpreting the voice commands via Google’s speech recognition tool. The ‘bot itself is a fairly simple design using brushed gearmotors for propulsion and a 3D-printed chassis to tie everything together.

The car is capable of understanding five commands – drive, turn left, turn right, go backwards, and “attack”. The last command simply activates a flipper from the robot’s former life as a battlebot. Things ran okay at first, but the Pi Zero was slow at processing commands. The wheels also had minimal traction. A full-fat Raspberry Pi solved the latter issue, while a new chassis provided better grip.

It’s a simple project, but one that taught [Robotcus] plenty about programming and building small robots in the process. Like so many learning experiences, it’s easy to see how the robot starts out flailing uselessly and eventually starts to perform as intended. It’s always nice to see that progression. Video after the break.

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Retrotechtacular: Rebuilding A Fire-Ravaged Telephone Exchange

January 11, 2024 by 15 Comments

Those who haven’t experienced the destruction of a house fire should consider themselves lucky. The speed with which fire can erase a lifetime of work — or a life, for that matter — is stunning. And the disruption a fire causes for survivors, who often escape the blaze with only the clothes on their backs, is almost unfathomable. To face the task of rebuilding a life with just a few smoke-damaged and waterlogged possessions while wearing only pajamas and slippers is a devastating proposition.

As bad as a residential fire may be, though, its impact is mercifully limited to the occupants. Infrastructure fires are another thing entirely; the disruption they cause is often felt far beyond the building or facility involved. The film below documents a perfect example of this: the 1975 New York Telephone Exchange fire, which swept through the company’s central office facility at the corner of 2nd Avenue and 13th Street in Manhattan and cut off service to 300 blocks of the East Village and Lower East Side neighborhoods.

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Linux Fu: Name That Tune

January 11, 2024 by 9 Comments

If you aren’t old enough to remember, the title of this post refers to an old game show where contestants would try to name a tune using the fewest possible notes. What can we say? Entertainment options were sparse before the Internet. However, using audio fingerprinting, computers are very good at pulling this off. The real problem is having a substantial library of fingerprints to compare with. You can probably already do this with your phone, and now you can do it with your Linux computer.

In all fairness, your computer isn’t doing the actual work. In fact, SongRec — the program in question — is just a client for Shazam, a service that can identify many songs. While this is mildly interesting if you use a Linux desktop, we could also see using the same technique with a Raspberry Pi to get some interesting projects. For example, imagine identifying a song playing and adjusting mood lighting to match. A robot that could display song information could be the hit of a nerdy party.

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Building A Loop Station With An RP2040

January 11, 2024 by 9 Comments

Loop stations are neat things, able to replay one or more loops of audio over and over again while you perform over the top of them. Musicians like [Marc Rebillet], [Reinhardt Buhr], and [Dub FX] have made careers out of this style of performance. [Yaqi Gao], [Xiaoyu Liang] and [Alina Wang] decided to build a loop station of their own, using the popular RP2040 chip.

At its simplest, a loop station must take in audio, record it, and then play it back. Generally, it can do this with several tracks and mix them together, while also mixing in the incoming audio as well. The group achieved this by inputting a guitar signal to the chip via an amplifier and the onboard analog-to-digital converter. The audio can be recorded as desired, and then played back via an external digital-to-analog converter. Live audio from the guitar is also passed through to allow performing over the recorded sound. The group also used an external half-megabyte FRAM chip to allow storing additional audio sample data, which can be trucked out over serial and saved.

It’s not the cleanest loop station in the world, with a relatively low sample rate causing some artifacts. Regardless, it definitely works, and taught the group plenty about working with digital audio in the process. For that reason alone, we’d call it a success.

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NASA Adjusts Course On Journey To The Moon

January 11, 2024 by 61 Comments

It’s already been more than fifty years since a human last stepped foot on another celestial body, and now that NASA has officially pushed back key elements of their Artemis program, we’re going to be waiting a bit longer before it happens again. What’s a few years compared to half a century?

The January 9th press conference was billed as a way for NASA Administrator Bill Nelson and other high-ranking officials within the space agency to give the public an update on Artemis. But those who’ve been following the program had already guessed it would end up being the official concession that NASA simply wasn’t ready to send astronauts out for a lunar flyby this year as initially planned. Pushing back this second phase of the Artemis program naturally means delaying the subsequent missions as well, though during the conference it was noted that the Artemis III mission was  already dealing with its own technical challenges.

More than just an acknowledgement of the Artemis delays, the press conference did include details on the specific issues that were holding up the program. In addition several team members were able to share information about the systems and components they’re responsible for, including insight into the hardware that’s already complete and what still needs more development time. Finally, the public was given an update on what NASA’s plans look like after landing on the Moon during the Artemis III mission, including their plans for constructing and utilizing the Lunar Gateway station.

With the understanding that even these latest plans are subject to potential changes or delays over the coming years, let’s take a look at the revised Artemis timeline.

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a) Schematic illustration of energy storage process of succulent plants by harnessing solar energy with a solar cell, and the solar cell converts the energy into electricity that can be store in APCSCs of succulent plants, and then utilized by multiple electrical appliances. b–d) The energy is stored in cactus under sunlight by solar cell and then power light strips of Christmas tree for decoration.

Succulents Into Supercapacitors

January 11, 2024 by 17 Comments

Researchers in Beijing have discovered a way to turn succulents into supercapacitors to help store energy. While previous research has found ways to store energy in plants, it often required implants or other modifications to the plant itself to function. These foreign components might be rejected by the plant or hamper its natural functions leading to its premature death.

This new method takes an aloe leaf, freeze dries it, heats it up, then uses the resulting components as an implant back into the aloe plant. Since it’s all aloe all the time, the plant stays happy (or at least alive) and becomes an electrolytic supercapacitor.

Using the natural electrolytes of the aloe juice, the supercapacitor can then be charged and discharged as needed. The researchers tested the concept by solar charging the capacitor and then using that to run LED lights.

This certainly proposes some interesting applications, although we think your HOA might not be a fan. We also wonder if there might be a way to use the photosynthetic process more directly to charge the plant? Maybe this could recharge a tiny robot that lands on the plants?

Faking Bluetooth LE With An NRF24L01+ Module

January 11, 2024 by 11 Comments

Despite the name, Bluetooth Low Energy (BLE) has very little to do with the original Bluetooth, other than its use of the same 2.4 GHz frequencies. This is where [Dmitry] got the idea to use a 2.4 GHz nRF24L01+ module to implement his very own BLE device, without the typical BLE chipset. This should be easy, since this popular IC supports GFSK modulation, 1 MHz channels and the 1 MBit data rate of BLE.

Despite of how simple BLE seems to implement, [Dmitry] quickly came across a range of issues due to limitations of the nRF24L01+. These include no support for a 24-bit CRC, a too sluggish PLL cycling for BLE’s frequency hopping, and as the coup de grâce, a lack for incoming data packets larger than 32 bytes — which destroyed any hope of accepting incoming connections.

Unperturbed, [Dmitry] set to work implementing what would work on this IC: broadcasting BLE packets. In the article he covers the entire code (in C) that allows the nRF24L01+ to send broadcast packets and any BLE-supporting device that’s listening to receive them. Admittedly not as useful as having a fully functional BLE stack, but good enough for broadcasting something like sensor data. It also raises the question of which alternative released in the intervening decade to the venerable nRF24L01+ might fill in the missing features, without making a dedicated BLE IC (or ESP32 variant) look more cost-effective.

It’s always a good day when a new project from [Dmitry] hits the tip line. We’ve previously covered his impressive efforts to add more RAM to the RP2040, and his business card that can boot Linux on an ATSAMD21.