fabiochiu/medium-articles huggingface dataset:
Focal has a new entry-level model in its high-end headphone lineup: The closed-back, over-ear Celestee
Tags: Connected Home, Surveillance, Security Cameras, Entertainment

Focal has a new entry-level model in its high-end headphone lineup: The closed-back, over-ear Celestee Elise Feb 2·2 min read

After more than 40 years making outstanding audio products, but less than a decade in the headphone business, Focal quickly established a well-deserved reputation for stellar-sounding cans—albeit at out-of-this-world prices. In 2018, the company introduced the Elegia for a list price of $899, making it the least expensive of Focal’s high-end consumer headphones.



Today, the French audio stalwart introduces the Elegia’s replacement—the Celestee. Like all Focal headphones, the Celestee promises stunning sound quality and superb craftsmanship. Its circumaural (over-the-ear), closed-back earcups house the company’s proprietary 40mm dome diaphragms, dubbed “M-shaped” because of their cross-sectional profile, in this case fabricated from an aluminum/magnesium alloy. Also, they implement sophisticated acoustic treatments that promise to virtually eliminate resonances.



[ Further reading: The best headphones you can buy ]The specs speak for themselves: frequency response from 5Hz to 23kHz, sensitivity of 105dB SPL at 1 mW/1 kHz, and THD of 0.1% at 1kHz/100dB SPL. Also, the Celestee’s low input impedance of 35 ohms allows it to work well with smartphone and high-res portable audio players. Focal touts a tonal balance with deep bass extension and precise mids and highs, which I don’t doubt based on my experience with other Focal headphones.



Focal Focal’s new Celestee closed-back, over-ear headphones will replace the Elegia at the (relatively) low end of Focal’s personal listening offerings.



Of course, comfort has not been neglected. The earpads and headband are covered in semi-aniline (referring to the type of dye used) leather with microfiber on the inner surface of the headband, and the aluminum yoke molds to the shape of your face. In addition, the earpads are said to provide excellent sound isolation—which, again, I can well believe based on my experience.



Stylistically, the color scheme is navy blue with copper accents, colors that carry over to the included hard-shell carrying case and 4-foot cable. The colors were selected in consultation with designer and product colorist Doris Bölck, who says, “Navy is the new black.” This marks the first time that blue has graced a Focal headphone. Overall, the look is clean, modern, and sophisticated.



The Celestee will be available in late February/early March for a list price of $990. That’s certainly not inexpensive, but it’s less than any of Focal’s other over-the-ear consumer headphones. And if its performance is comparable to its predecessor, the Elegia (reviewed here), it will be a worthy successor.



For more info on the new Celestee, click here.



Note: When you purchase something after clicking links in our articles, we may earn a small commission. Read our affiliate link policy for more details.
The Nobi smart lamp can detect when a person falls in their home and will call for assistance
Tags: Security Cameras, Audio, Services

The Nobi smart lamp can detect when a person falls in their home and will call for assistance Jason Feb 2·2 min read

As the baby-boomer generation swells the ranks of America’s oldest population, an increasing number of smart home product developers are looking to help them age in place. The Nobi smart lamp is a case in point, having been designed to detect when a person falls in their home. It can then call for emergency assistance.



Nobi The Nobi smart lamp is designed to replace an existing ceiling fixture. Its onboard camera and artificial intelligence can detect when a person falls in the home and can summon help.



The euro-modern-style lamp will be available in two configurations, both of which are designed to replace an existing ceiling fixture: The Nobi and the smaller Nobita, which offers the added benefit of humidity resistance, so that it can be installed in a bathroom. In addition to fall detection, the lamps can also detect fire, monitor air quality, and recognize a burglary in progress.



[ Further reading: The best smart home systems ] Nobi The smaller Nobita offers the same features but is resistant to humidity and can be installed in a bathroom.



Both lamps are outfitted with a camera, speaker, and an onboard processor that can perform image processing on the device itself, enhancing privacy by not uploading them to the cloud for that task. If a fall is detected, the Nobi’s speaker will ask if the resident is OK. If there’s no response, the smart lamp will call the person’s emergency contact list. The resident has the option to share captured images with those contacts in the event of an emergency.



Nobi says it will cost about $2,500 to outfit “an average apartment,” but doesn’t specify how many smart lamps that would include or the amount of square footage each one can cover. In addition to the purchase price, you’ll need to sign up for a $19-per-month subscription. Alternatively, you can rent the equipment for $119 per month, subscription included.



The Nobi and Nobita smart lamps are expected to be available by the end of 2021.



Note: When you purchase something after clicking links in our articles, we may earn a small commission. Read our affiliate link policy for more details.
IRIS SECURITY
By: Iris Engineering
Tags: Security Services, Security, Cctv, Security Camera

It is Monday morning. Everyone’s preparing to get into the office to begin work for the week but notices some of the company’s devices have be carted away.

THE QUESTION: WHO DID THIS, becomes the talk of the day.

Our everyday activities involve a lot of risks, and it is expected that we do all we can to ensure these risks don’t cause harm. One major way of mitigating our everyday risks is being security conscious. The lack of being conscious of our properties and valuables can put a lot of us in harm’s way both at home and offices.

WE PRESENT TO YOU, IRIS SECURITY, AFRICA’S FOREMOST DIGITAL SECURITY COMPANY.

At IRIS, your security is our priority and we help you stay safe stay with our security gadgets and CCTV cameras, that can be installed anywhere in your homes, office spaces, business areas, event halls, malls and specific locations to keep you abreast of any form of insecurity.

We act as a covering, as a risk mitigating organization to ensure your safety and protection.

The value of securing lives and property cannot be overemphasized.

We know this at Iris, and our goal is to secure, protect, cover and preserve you, your homes, your office or business areas and wherever you need us.

Think security, Think Safety, Think Protection, THINK IRIS.

Contact us today: +234 9038040734
Factors to Consider When Buying a 4K Security Camera
By: Dyna Post
Tags: Shop Cctv Dallas, Security Cameras Dallas, Cctv, Security Camera

We all need to be secure, whether we are at our home, workplace; a mall, or anywhere, security is crucial. The first thing that comes to our mind when it comes to security is a Dallas CCTV camera.

There are different types of security cameras varying in quality and price. The highest noted quality of a camera is 4k which is very high, impressed? But wait don’t just go in and blindly buy and install a 4k camera yet.

Today we will tell you some factors before you buy a 4k security camera for your home or business.

Storage and applications

A 4k camera is best suited for schools, businesses, and government organizations since these are the institutions that need high-quality recorded and or live footage. The footage recorded by 4k Security Cameras Dallas is amazingly detailed; you can zoom in on distant objects without pixelation.

We know that security cameras are used to claim insurances and report to the police after the incident, you need to have clear footage that can identify any criminals, workplace incidents, car accidents, etc.

You should also know that most 4k cameras come with a network video recorder or NVR with 4, 8, 32, 64, and 128 channels, some of the best hard drives come with hot-swap capability, which allows you to swap segments of storage without shutting down NVR.

The above feature is good for institutions that can’t risk surveillance downtime, but for other organizations, we would recommend giving it a second thought, because, the higher the channel the larger space. We would recommend consulting with experts from CCTV Camera Systems Dallas.

Power of the best 4k cameras

Now you have decided to buy a 4k camera, let’s look at the features of the best 4k security cameras since we would like you to only have the best Video Surveillance Dallas.

1. It has at least 8-megapixel image sensors to support a 3840*2160 resolution, which is a lot.

2. It has high video clarity.

3. 4k CCTV cameras come with HD digital zoom; you can zoom in 4 times as compared to lower resolution systems without pixilation.

4. Wide-angle viewing for a long-range, so that you can cut down on costs because you can monitor a wider area with fewer cameras.

5. A good 4k camera has infrared for better night vision for clear night footage as well.

6. It has remote viewing so that you can view the footage from anywhere.

7. The best 4k systems have an advanced video analytics feature that allows you to track objects with minimum false motion detection alerts.

You should ask yourself a question that, are these features needed for my security? If your answer is positive only then you should buy a 4k surveillance camera.
Top 6 advantages of high-security cameras
By: Himani Joshi
Tags: Security, Cctv Security Cameras, Security Camera

CCTV security systems are one of the most widely-used and extraordinarily beneficial security components around the whole world. They have several benefits including, being an effective crime deterrent, as well as an efficiently reliable means of surveillance and, if the need arises, a good source of forensic data also.

CCTV surveillance cameras were primarily meant only to record video, but the sheer number of cameras, the volume of data, and security and law enforcement requirements have led CCTV equipment manufacturers to raise the stakes and provide a wide array of specific features with the help of advanced technologies.

Some of these features are relevant to all CCTV users and required by the Home or Office to anyone who wishes to deploy a CCTV security surveillance camera. Advantages High-security cameras are equipped with new-generation technologies ad advanced features, so they serve excellent benefits to the consumers.

Some of the major advantages presented by high-security cameras are-
Home alarm systems vs security cameras? Find out what is missing for your home and how you can improve the safety of your home.
By: Max Security
Tags: Safety, Security Cameras, Internet of Things, Alarm Systems

Home alarm systems vs security cameras? Find out what is missing for your home and how you can improve the safety of your home. Max Security May 2, 2019·2 min read

As you’re equipping your home with security measures, you’ll find that cameras and alarms are two of the most effective tools on the market. Both warn you of oncoming danger, but they do so in very different ways. Here’s how each of these security tools can help boost your home’s defenses.

Security Cameras

Placing cameras around your property is a smart strategy, whether you’re at home or out traveling. An effective system of cameras will capture video of everything that’s happening on the premises. Set up a camera on each side of your property, as well as several with crisscrossing views of the front and backyards. This will provide maximum coverage, but be sure to include proper lighting as well.

Some wireless cameras will capture and transmit images via Wi-Fi. Other options use cables. The sight of cameras alone will often be enough to deter most intruders.

However, if you choose a wired camera system, make sure the cables are out of sight. Otherwise, intruders could tamper with them. In fact, you might want to leave the setup process to professionals like those at Max Security. They can get the system up and running, and even offer instructions on how to use it.

Alarm Systems

An alarm system won’t capture footage — so, unlike cameras, they’re not very useful for collecting evidence. However, they’re extremely useful for deterring intruders as they sneak around. Burglar alarms will sound whenever unauthorized individuals open doors or windows. These alarms are triggered by sensors that are placed around the home or even outdoors.

You can use alarms to warn of dangers beyond intruders. Some companies provide systems that will omit a noise in the presence of fire of carbon monoxide. Environmental sensors can also detect problems like leaking pipes or flooding.

Newer alarm systems offer you the option of cellular monitoring. This allows you to control the system even when you’re away from home.

Total Home Security

You don’t have to choose between cameras and alarms. If security is a high priority for you, select both options. The alarm system will warn of present dangers, and camera footage can be used to identify thieves who are bold enough to ignore the alarms. The result will be a more secure home, and you can have peace of mind whether you’re at work or overseas on vacation.
Stealth Security Suggests These Key Camera Features for Banks and Credits Unions
By: Get Stealth Security
Tags: Cctv, Security Camera

As institutions that insure cash in banks against burglary or any other kind of loss, the FDIC and National Credit Union Administration both require these establishments to be observed by security cameras. Certainly, the cash that people have handed over to them is a most important concern for such bodies. “Devoid of particular rules from their insurers regarding needs for their monitoring systems, a lot of financial bodies have found themselves with sub-par systems that make recognizing a bank or ATM thief almost impossible. And this is where the professionals at Stealth Security come into play,” says the owner of Stealth Security.

Here, the owner of Stealth Security mentions the important features for bank security camera systems in Chicago:

High-resolution Cameras: In line with the senior salesperson at Stealth security, some time ago, we assisted a client in getting back recording of a bank theft from their security camera system. In the absence of a high-resolution security camera system, the bank found itself asking what the reason is that its security images are of so inferior quality.

The professionals always encourage businesses to have cameras in public zones to assist next-door businesses and the societies stay protected and assist law enforcement investigations. In case, it has been a while since your system was set up and you’ve found yourself struggling with meagre quality images, it may be time to get better your camera tool.

Motion Detection & Tracking: It is good to know that most financial institutions don’t have physical security on around the clock basis. And that is where Chicago home security systems with motion detection as well as motion tracking features can truly improve your after-hours security. You might not be aware but the fact is that by freely tracking moving objects in real time, your camera can even send smart alerts when somebody gets in a monitored zone while the bank is closed.

About Stealth Security

This renowned security cameras company is a one-stop store to meet all your security requirements together with design as well as installation support at a reasonable price in Chicago and surrounding suburbs. Our skilled experts provide you with the whole lot, from free consultation for resolving online queries to bespoke security systems based on precise needs at your doorway. To know about the range of their security camera systems in Chicago, please go to www.getstealth.com/.
C.O.C. Surveillance: Security System Installation in Texas
By: Coc Surveillance
Tags: Cctv, Security System, Security, Security Camera, Video Surveillance

Industrial & Commercial Solutions

If you manage a commercial or industrial property, you know how big of a job security can be. To make your job easier, allow our alarm systems and access control products to help make your task much easier. Protecting an entire building inside and out is no easy feat, but with the proper tools, equipment and accessibility, you’ll have no trouble at all.

Please call (936) 588–7410 to discuss which alarm system is right for your specific application. We’ll help increase communication around your property so you can track all traffic and activity.

• Surveillance Systems

Surveillance Systems and Installation

From interior to exterior cameras, we can make sure your home or business is equipped with all the necessary tools to ensure you are safe and secure. We sell quality surveillance products from some of the top camera manufacturers in the country, at affordable prices. You will have the ability to view your cameras remotely from anywhere, right from your smartphone.
Why Every Household Should Install Home Security System In His Home?
By: Nikii Brown
Tags: Internet of Things, Home Security Systems, Home, Security Camera, Safety

When you see your family and your home, you know that you want them to be safe, always stay out of harm’s way. When you leave for work, you expect to come back to the family, smiling and returning to the safe living house. But as they say, hope is not a strategy. Increasing crime rates in cities show bitter reality. Many people ignore the need to take appropriate measures to protect the home, ignore and ignore them. Theft or theft can have emotional and financially devastating consequences. While financial loss may be recoverable, trauma strife on your family and yourself may be forever.Home security systems should be in every home of US. It is a life saver and is like an insurance policy for you and when you are in any trouble or loss you provide the necessary evidence.

Importance Of Having Home Security Systems

Home security is a major issue of concern because it is not only about your financial or monetary security but also more than that. Everyone wants the happiness and security of their beloved. No one can see his family members in danger or in a problematic situation. This is important because home security is important.Nowadays crime rates are increasing fast every day. Every day we can see in the news that someone killed his mother for a girlfriend, a girl was raped, a couple was murdered, a family was robbed etc. These news have become a common scenario in our society.These questions arise the need for adequate security arrangements in our house. Installing Home Security Systems is the best way to keep your home safe when you are not at home. You can also use these features even when you are around — even when you are only sleeping or just having a meal with your family.With the help of smart security system, you can keep hawk’s eye on / around your home. Home security cameras and motion sensors protect your home’s sweet home from intruders.

Before choosing an advanced home security system like Sure, you need to decide on three important things.

1. How much are you willing to invest? While some systems offer excellent features, they are also very expensive. So it is always advisable to do some research and choose what works for you.

2. How much coverage do you need? While some systems come with multiple units that can be installed around the house, others involve alarms for doors and windows. But the simplest alternative for Indian conditions is to secure doors and windows with grills that are hard to break into, and choose a single camera-based unit for the front door.

3.What are the features you need? While some systems record video continuously and let you rewind and review footage, they are usually difficult to maintain. The best choice is to choose one which has a proximity and movement sensor, and only records when it senses someone approaching. If the solution also offers cloud-based storage and can connect to your phone, just go for it!
Product: Uber. What I like ?
Tags: Uber, Product, Security Camera, Product Management, Safety

What I like ?

Company’s Vision Statement and how apt it is : “Transportation as reliable as running water, everywhere for everyone” . Uber does set the world in motion. What else does one want other then tapping a button and requesting a ride home, safe and reliable.

When I first used an Uber to commute from A to B, 6 years ago, I was so impressed. With the tap of a button I had a driver in less than 5 minutes waiting to pick me up. I was so excited about the convenience that it started to be a goto product every time I had to commute.

I visited India in 2019 and I was amazed by their presence. I realized the app was growing worldwide making everyones life easier.

Every time I traveled via Uber, I always wondered how safe it really was. I kept re-reading the safety protocols and I now know it at the top of my head; they do have great checks in place for sure- drivers background checks, emergency help when you need it, RideCheck to look out for you. With that in my mind the other day I thought of a new feature that Uber can introduce for the safety of their passengers.

My new product thoughts on RideCheck/ Emergency Help?

Imagine you do not have enough battery on your phone. Imagine you are unable to call/request for 911 through the Uber app. Imagine the car is in the right course and has not triggered any deviated route alert and you need “HELP”. During this time, how about a small device in the car that is video enabled helping to track the activity in the car. When the device is turned off- the driver will not have the ability to drive a new passenger home. And on your journey, assume this video device was turned off by the driver when the ride was ongoing. The driver will have 30 seconds before Uber reaches out to them and asks them about the device connectivity. He will further only have another 45 seconds before the car is stopped by an Uber authoritative security official. Does these extra checks make you feel more secure? What are your thoughts?

Safety Concerns of Video Capture

Lets discuss this on a separate article as this needs more thought to it.

“Safety does not come by luck, it comes prepared”
UNDER VEHICLE SURVEILLANCE SYSTEM (UVSS)
By: Bala Murali
Tags: Automation, Home Security Products, Security, Security Camera, India

Hello Everyone! Greetings from Magtech!

Magtech security systems private limited is one of the leading OEM Company in Chennai and manufacturer of all kinds of security products. Our branches have been located in Pune, Mumbai, Kolkata, Hyderabad, Bangalore and Delhi. We delivering our products with great quality assurance and cost efficient for our clients. Magtech main motto is to provide best security for people and society. We enrolling ourselves to create innovative and remarkable technical specification. We supply X-ray baggage scanner, Door frame metal detector, UVSS, Boom barrier, swing barrier, Flap barrier, High speed barrier, Tripod turnstiles, Cargo scanner and Hand held metal detectors.

Under Vehicle Surveillance System uses machine vision technology to grab the full and high resolution image of vehicle chassis. Moving vehicle can be detected with the help of loop sensor. At the same time the image of the vehicle chassis and the license plate will be captured at same time and then transferred to computer. High resolution camera will give clear and sharp images even in the day time. It is the combination of hardware and software used for scanning the undercarriage of vehicle. Main purpose of UVSS is to detect any explosive items have been carried by any person under the vehicle. When a vehicle passed through the checkpoint operator will check and identify whether any explosives have been placed under the vehicle. UVSS can be classified as portable and constant. We developed our UVSS with world class technology with real time color area scanning technology and has unique sailent features. We installed our UVSS in Government sectors, corporate office, malls, airport, Railway station, Defence regiments where vehicle monitoring is highly recommended. Customer’s feeling happy with the output given by our product acquired which satisfied their requirements as they expected. It is easy to inspect Vehicles by both day and night. Our project team is readily available to solve your queries.
A Security Camera System Plays An Important Role In Your
By: Axel Agüero
Tags: Insecurity, Inseguridad, Security Camera

A Security Camera System Plays An Important Role In Your

A Security Camera System Plays An Important Role In Your Home Security.

To observe what’s going on, you can add to your home security system a security camera system. They are the ultimate home security product. Whether you live in a spacious estate, in a gated community, or have a house in the suburbs, they are designed fit your needs. Video cameras are an advanced addition for your home security system. The most basic security camera system would be a single camera connected directly to a monitor and a recorder to store the video.

Types:

There are several different types of security cameras. A few security cameras are black and white security cameras, color security cameras, wireless security cameras, night vision security cameras, and vandal resistant security cameras. Besides differing in function and design, security cameras also vary in price. Some security cameras also allow remote access, therefore allowing access to the monitors through an Internet connection.

Size & Resolution:

Video monitors come in a variety of sizes. It is best to buy a larger monitor because the smaller ones may be hard to view. CCTV monitors may have as many as 1000 lines of screen resolution as compared to 550 lines on ordinary televisions. This shows that security monitors do have their place in a home security system.

Advantages:

The advantages to owning a security camera in your home include:

It has the ability to monitor people in your home. They can even save you money on your homeowners insurance. Its easy for you to know who is in your home at all times with remote access.

Security:

CCTV (Closed Circuit Television) Security Systems is a fast growing segment of the security market. They are a relatively cheap addition home security systems. The security system consists of cctv security cameras, security monitors, sensors and cabling. Wireless cameras provide an extra measure of coverage since they can be positioned anywhere quickly. These are good trends in the security industry.
How to Import External Smart Contracts and Libraries in Solidity
By: Alex Roan
Tags: Solidity, Ethereum, Programming, JavaScript, Blockchain

Installing and Importing

OpenZeppelin is the gold-standard reusable repository for Ethereum smart contracts. In this project, we’re going to install the contract repo as a dependency, then import the Ownable contract so we can restrict access to certain functions.

You may have seen or used a similar pattern before. When the contract is initialized, the msg.sender address is stored in a state variable indicating the owner of the contract. Using a custom modifier _onlyOwner , certain functions restrict access by requiring that the msg.sender is equal to the owner.

In the repository root, run:

npm install @openzeppelin/contracts --save

Once completed, you should see a new folder in your root named node_modules/ (if you’ve used Node or npm before you know all about this).

Inside node_modules , npm has downloaded the OpenZeppelin/contracts repo, in which live all the contracts and libraries that OpenZeppelin has to offer. Take a moment to have a browse at what is on offer.

We’re going to use the Ownable contract, which, from the project root, lies in @openzeppelin-solidity/contracts/access/Ownable.sol .

In the contracts/ folder, create a new Solidity file that will import the Ownable contract. I’m going to call mine TestContract.sol .

The first thing is to declare the Solidity compiler version, we’re using 0.6.0 ; then we need to import the Ownable contract using the path we found it; and finally, we need to declare the contract and that it extends from Ownable .

Figure 2 shows the skeleton contract once we’ve done all this.

Figure 2: TestContract.sol

Believe it or not, that’s pretty much it!

When writing new functions in this contract, we can add the onlyOwner modifier just after the public , private , internal , or external modifiers to declare that the function should only be run by the owner.

Here’s a simple example:

// This function has no restrictions on who can call it

function noRestrictions() public { ... } // This function is restricted only to the owner. Anyone else

// who tries to call it will result in a reverted transaction

function restrictedFunction() public onlyOwner { ... }

To make sure the contract compiles when you’ve added your new restricted functions, run:

truffle compile

If all is well, you can start working on migrating your contracts to a local blockchain, writing tests, and deploying to a public testnet!
Getting Started With Brownie (Part 3)
By: Ben Hauser
Tags: Solidity, Smart Contracts, Ethereum, Python, Programming

Getting Started With Brownie (Part 3)

Photo by André François McKenzie on Unsplash

Now that we’ve installed Brownie and created a project, it’s time to get acquainted with some of the core functionality.

If you haven’t yet, start by opening the console:

brownie console

Brownie will launch Ganache and create some objects to help you interact with your project. Once it’s ready, you are given a command prompt:

For the newcomers to Python, it’s time to level up! Let’s take a look at two very useful built-in functions:

dir displays a list of objects within the namespace or a list of members of an object. If using Python feels like visiting a foreign country to you, then think of dir as your roadmap.

help accepts any object as an argument and displays documentation for the object. Continuing with our previous analogy, if dir is your roadmap, then help is your guidebook.

With these two functions and a healthy dose of curiosity, you can pretty much figure out how to do anything without reaching for the documentation. (But please do open the Brownie documentation. I put a lot of work into it.)
Simple Contract With Remix
Tags: Remix, Ide, Solidity, Ethereum

Create a new contract called “SimpleStorage.sol” inside the file explorer.

This simple contract defines a string named value that gets initialized in the constructor and gets saved in the storage. This string is updated with the method setValue . When the value is updated, it emits an event ValueChanged .

But… It doesn’t compile ??? And for that matter, where do you click a button to compile it???

Remix is now divided into Plugins that can be loaded individually. This makes Remix more customizable. So, for example, if you want to use Vyper, you don’t need Solidity compiler.

Compile your Contract

Click on the “PluginManager” icon on the left bar (it’s the one that looks like a plug). Here you’ll see all available Plugins inside Remix.

Activate “Solidity Compiler”.

Click on the new solidity icon to open the Solidity Compiler panel. Hit “Compile”, or just click inside the editor and hit “Ctrl/Cmd+s”.

Test your Contract

Now that your contract is compiled, you’ll want to verify that it works. Let’s use the Remix Test Plugin for that.

Under the Plugin Manager panel, activate “Solidity Unit Testing”. You should now have two plugins activated :

Inside the “Solidity Unit Testing” panel you will find the documentation and examples to build your solidity tests.

Let’s write our solidity test file from scratch.

Go back to the FileExplorer and create a SimpleStorage_test contract (the name needs to end with _test to be considered as a testing contract):

First we import the remix_tests.sol library as well as our contract ./SimpleStorage.sol . Then we create the contract and define a variable testContract that will be reassigned before each test.

It’s important to use beforeEach because the library doesn’t run the tests by order of definition, but by alphabetic order. In this case shouldChangeValue will be test before shouldHaveAValue .

The library exposes the method equal that check if the two first parameter are equal, and display the third if not.

Run the tests

Go back to the Solidity Unit Testing panel. Check you contract, and hit “Run Tests” :

As you can see in this example, the first test is “Should change value”, and the second one is “Should have a value”.
Spartans set new record for Code4rena audit contest participation
Tags: Solidity, Security Audit, Ethereum, Security, Bounty Program

Code4rena audit contests hit a high water mark this week, with the Spartan Protocol contest drawing over 20 security researchers submitting over 220 security issues in competing for their share of the $80,000 USDC pool.

(Typical contests in the past have run 5–12 competitors generating 50–150 security findings.)

The contest’s security issues are being reviewed by the Spartan Protocol team and soon will head to judging prior to awarding the $80,000 USDC.

Not a bug bounty, an audit contest

Unlike bug bounty programs, there’s no spec work in Code4rena’s audit contests.

Projects are typically seeking audits on fresh code so there’s definitely vulnerabilities to be found for security researchers and solidity devs of a wide range of skill levels. And if a researcher submits a valid bug during the contest they’ll get paid for it —even if someone else submits the same bug first.

Big money bug hunt

With the audit contest format, researchers are getting paid well. C4 has now paid out $750,000 in awards.

Based on awards from our first four months of contests:

Code4rena’s #1 and #2 wardens — cmichel and 0xRajeev — are about to pass $200,000 and $150,000 in total earnings.

and in total earnings. The top 5 have earned over $80,000 each.

The top 50% have earned over $15,000 each— and some of those wardens have only competed in a handful of contests.

Results on the money

Sponsors have been happy with the results, too.

“This result far exceeded previous experiences I’ve had with 2–4 week-long audits by individual companies. I highly recommend the Code 423n4 competitive audit approach for anyone starting a new project and propose that we use it again in the future as we roll out new smart contracts.” — LSDan, ElasticDAO

Oh and Code4rena audit contests tend to be faster to book, too!

“There was really great feedback. Can’t get audits done this quickly even in a bear market. We’ll definitely be back!” — Layne, Connext

Want to sponsor a contest reviewing your smart contracts or participate as a researcher in an upcoming contest?

We presently have open windows on our schedule as soon as next week.

Just hop into Discord and say #i-want-to-be-a-sponsor. If you’re looking to compete, just howl #i-want-to-be-a-warden in our community chat.
How to Setup Hardhat and compile, test and deploy contracts using it ?
By: Dheeraj Kumar
Tags: Solidity, Ethereum, Hardhat, Truffle, Blockchain

How to Setup Hardhat and compile, test and deploy contracts using it ? Dheeraj Kumar Jul 22·2 min read

This tutorial is about how to setup Hardhat and how to compile, test and deploy smart contract using this.

Firstly, Hardhat is basically a development environment to compile, deploy, test and debug Ethereum smart contracts. It serves as an alternative to truffle. However, it is a lot better than the latter. Hardhat had a built-in Hardhat Network (like Ganache, your local blockchain) designed for development. Its main functionality focuses around Solidity, debugging, featuring stack traces, console.log() and explicit error messages when transactions fail.

Hardhat is used through local installation in your project.

To install it, create an npm project by going to an empty folder, running npm init in the terminal.

Then, run npm install — save-dev hardhat to install hardhat as a development dependency.

Create your Hardhat project by running npx hardhat in project folder.

Then you’ll get two options:

1. Create a sample project

2. create an empty hardhat.config.js file

If you select the second option, an empty hardhat.config.js file will be created and you can then configure the dependencies as per your requirements (we’ll discuss about this in next article).

Follow the steps to get an idea how to compile, test and deploy contracts.

Select the option to create a sample project.

Then, you’ll have to install hardhat-waffle and hardhat-ethers.

You can use hardhat-waffle plugin to build tests for smart contract using Waffle in Hardhat and hardhat-ethers brings to you the Ethereum library ethers.js that allows you to interact with the Ethereum blockchain in a easier way.

You can install it by running npm install — save-dev @nomiclabs/hardhat-ethers ethers chai @nomiclabs/hardhat-waffle ethereum-waffle

To get an idea about what’s there in hardhat for you, run npx hardhat in your project folder. This will give you a list of built-in tasks.

To execute any task, say you want to check version( — version), run npx hardhat — version

Or if you want to execute accounts, run npx hardhat accounts

Compiling your contracts: You’ll find a sample contract in our project. However, you can add your own. To compile it, simply run: npx hardhat compile

The sample project comes with tests that use waffle and ethers.js . You would see a sample-test.js in test folder. You can write your own tests in your project.

You can run your tests with npx hardhat test.

Next, to deploy your contracts we’ll use Hardhat script. The sample code is there inside scripts/ in the sample-script.js file

Run it with npx hardhat run scripts/sample-script.js

And whoa! You’re done. You have deployed contract to the local Hardhat Network.
by Zach of Mintable.app —A Next Gen NFT Marketplace
By: Zach Of Mintable.App, A Next Gen Nft Marketplace
Tags: Solidity, Ethereum, Marketplaces, Cryptocurrency, Blockchain

Starting Dates

When we go live with Mintable v2.0 we will also go live with the DAO. We are aiming to go live at the end of November.

DAO/Mintable v2.0 goes live: End of November

End of November Can start earning/buying MINT and NFTs: As soon as its live

Mintable.app will be taken down 2 weeks prior to launching and replaced with a landing page as we get closer to launch.

How a NFT DAO works

Mintable wants to be community driven, decentralized, and flexible. To do that a DAO is the best choice. Here is how it works:

The DAO doesn’t take tokens for voting, but instead uses NFTs. In order to submit proposals, vote in a proposal, you need a voting NFT with more than 10,000 votes to propose, and any number for voting.

Each person who wants to vote has an NFT that contains their voting power on it. Each NFT is unique, and each NFT is given to anyone when they buy/sell an NFT on our marketplace or via the bonding curve.

This means people who actively use our platform, have a say in our platform. Exactly what we want.

How to earn a voting NFT and get votes

If you make a transaction on Mintable.app — either buy or sell an NFT — you will be given an NFT automatically in the transaction that you purchased the NFT in. So if you buy an NFT, you will actually get 2 — the NFT you wanted to buy, and the voting NFT.

If you already have a voting NFT, your votes will increase, but you will not get a new NFT.

Example: Bob creates an NFT on Mintable and offers it for sale. This is Bob’s first NFT. Sally sees this new NFT and loves it, so she buys it for 100 USD, Sally buys a lot of NFTs and she already have a voting NFT with 5,000 votes on it. When Sally submits the transaction — she gets Bob’s NFT and her votes on her voting NFT increase to 5,100. Bob gets 100 USD and since it’s his first time selling an NFT or buying one, he is sent a voting NFT with 100 votes on it. (these numbers are made up and not accurate depictions of the amount of votes you’d get.)

The second method of getting votes is via a bonding curve. The DAO contract will sell NFT votes starting at roughly $2.50 per vote, with only 10 million votes available to be sold. This will allow people to start accumulating votes and earning rewards without having to wait the long game of selling multiple NFTs.

How proposals works

At any point a person with over 10,000 votes can make a proposal for the future direction of our platform. A proposal can be anything, either a proposal to change our logo, to changing our name, to adding a new feature, to adding an artist to the community approved artists, or adjusting our fees on our smart contracts. Proposals can be used to enact different features on the smart contract, if the community wants them, such as the ability to convert their NFTs into ETH, or to upgrade the DAO into a new smart contract. These are all just examples and will be dictated by whoever is making a proposal and then of course, if it’s passed.

How voting works
Intro to Solidity Linting and Formatting
By: Daniel Onggunhao
Tags: Solidity, Prettier, Prettier Solidity, Ethereum, Solhint

Part 1: Linter

Solhint and Ethlint (formerly Solium) are two fantastic community linters for the Solidity language. They’re like automatic code reviewers who flag up security errors and instills best practices across the team.

For this tutorial, we’ll focus on Solhint, though I highly recommend you take Ethlint out for a spin as well.

Solhint

First, make sure you are in the project root directory and then use NPM or Yarn to add the solhint module.

> npm install --save-dev solhint

Configuring Solhint

Initialize solhint with a basic configuration file.

> ./node_modules/.bin/solhint init-config

This should create a ./solhint.json file in your project’s root directory. This file specifies exactly which rules you want Solhint to lint for. Solhint has a pretty amazing coverage of Security Rules, Style Guide rules, and Best Practice rules.

One big gotcha: very few of the rules are turned on by default. After some trial and error, I found that solhint:recommended was slightly better (vs. solhint:default that Solhint lists in the documentation.

I’d highly recommend going through the rule lists and adding the ones you want to ./solhint.json . I’ve personally found the security rules and best practices very useful.

Solhint ignores

Similar to .gitignore , you can get solhint to ignore files and folders

node_modules/

migrations/

Solhint Script

Edit your package.json to include a new script to run Solhint.

"solhint": "./node_modules/.bin/solhint -f table contracts/**/*.sol"

The command above has a couple of things to note:

Solhint runs on globs that match a file pattern. In the above, it runs on all **/*.sol files in the contracts directory

runs on globs that match a file pattern. In the above, it runs on all files in the directory -f table presents the findings in a table format. You can choose from other options (e.g. unix , tap )

Solhint in action

> npm run solhint

You’ll likely see a bunch of errors, especially indentation and styling errors. You don’t need to fix these manually! Our next tool (the formatter) will help a lot with this.
mStable Dev Update — August. A recap of the progress made by the…
By: Alex Scott
Tags: Solidity, Defi, Ethereum, Mstable, Software Development

The month of August had a focus on securing the right engineers across the full stack who are going to help us take mStable to the next level. We are happy to say that we have substantially moved forward on that, with 3 great people coming aboard in early September 🔧🙎

Research & preparation

Staking is a priority from an R&D perspective at the moment — with a focus on ensuring that the correct types of behaviours are incentivised in the mechanism. We plan to capitalise on this thinking with more efficient EARN contracts in the near future too.

Contracts

mStable-contracts has gone from v1.1.0 to v1.1.4. See here for releases

Now available as a node package via npm

Successfully fixed some non critical issues — one of which to a Bug Bounty submission 🐛

merkle-drop contract developed, published and tested

Supports efficient airdropping through Merkle tree proofs

App

mStable-app has gone from v1.8.0 to v1.9.2. See changelog for granularity.

Features:

Provide a button for users to share a link to view their balances in a given pool

Custom Redeem 📊

Add support for redeeming with a custom selection of bAssets, so that users can redeem with a single bAsset, a selection of bAssets, or all bAssets (proportional redemption)

Show how redemptions affect mUSD and its basket of assets

CLAIM 💌

Generic implementation providing ability to view & CLAIM any platform reward (e.g. $BAL ) that has been accrued

Notable refactors/bugfixes

Adjust behaviour of approve button such that it is possible to either approve the exact amount or an infinite amount

When a new version of the app is available (according to Github releases), add a notification (that can be dismissed) with a button to refresh the page

Other Bug fixes/Miscellaneous: See the changelog for comprehensive list.
Solidity: Playing With Strings
By: Rosario De Chiara
Tags: Blockchain, Solidity, Ethereum, Hashing, Programming

Solidity: Playing With Strings

Photo by Martim Braz on Unsplash.

Strings of characters represent the very heart of every programming language because, you know, computers often interact with humans. For this reason, handling strings is one of the first functionalities developed in any language. Furthermore, the first test traditionally prints the string “Hello, world!”

Solidity is not an exception. It has native support for strings, but still, their use is not complete like in high-level languages such as JavaScript, Python, or Java. For instance, out of the box, Solidity does not offer a native way of comparing or concatenating strings. However, the documentation offers a valid solution for both functions that rely on abi.encodePacked() (we’ll talk about it later) to compare two strings:

keccak256(abi.encodePacked(s1)) == keccak256(abi.encodePacked(s2))

And to concatenate two strings:

abi.encodePacked(s1, s2)

To better understand the inner mechanics of these two simple functions, as usual, we will use a simple toy implementation:

As usual, you can comfortably play with it by using Remix. Once it is compiled, you will be able to invoke the two methods right from the interface:

The interface to invoke the methods.

Calling the two methods will sign a transaction containing an invocation to the method passing the arguments. The output of the transaction is displayed in the console windows following the execution of the string concatenation (to fully display the results, remember to click on the small arrow on the right):

Execution of the ‘concatenate’ method.

At the core of these two simple implementations is the function abi.encodePacked() , which performs a tight packing of the variables passed as arguments. In the following figure (taken from the documentation), you can see how the bits of each of the arguments are simply concatenated in the output:

An example of how the arguments passed to encodePacked are actually packed.

An interesting point in this encoding is that it is inherently ambiguous so there is no way of decoding it. In the following code, we simply test this ambiguity by comparing the encoding of two sets of different strings. With the in-place packing, the two invocations will return the exact sequence of bytes because both invocations will return the string "aab" without considering the different length of the input strings: