This channel has many instruction videos that I have created during the past several years. My formal background is as an Electrical Engineer, specializing in microprocessor-based electronic design. I have worked in Software development, Operating System support and, as a Cisco Certified Academy Instructor, teaching CCNA level networking courses at a Community College level. For the past few decades I have been an instructional designer and faculty at Nova Scotia Community College in Canada, teaching electronics, PC support, Operating Systems, Data Networks, Intro to creating Mobile Apps for iOS, and various other technology-related courses.
Recently I have purchased a Prusa 3D printer which is providing much enjoyment and speaks to the Engineer in me. Thus you'll also see recent videos about my creations in this area.
Now retired, I dabble in producing drinkable espresso, kayaking and making sure my Havanese pup, Mac, gets lots of exercise.
Thank you for sharing your experience with your Sunlu filament dryer. I just bought the same one and in one day of ownership, it has already shut down twice and has problems powering back up. I think the power supply is bad on the unit. Your video has convinced me to just return the unit and look elsewhere vs trying to contact Sunlu for any kind of warranty repair.
I am surprised at how large Sunlu appears to be that their products are as poorly manufactured. Combined with non-existent customer support I just don’t buy anything Sunlu
@davecrabbe4579 ,At 11:05, you said that we use public key of google CA to decrypt the hash of NSCC certificate. I have two doubts here: 1. First of all, as I am aware, hashing is irreversible, how can you decrypt a hash? 2. Public key is used for encryption, not decryption, right? Then this does not make sense. Could he be trying to say, that we use this public key that we receive from google, to again hash the contents of the certificate and then compare them to the original hash that is present in the certificate. If both are same, then we can be sure, the certificate content hasn't been modified. Would really appreciate if someone can clear this
Need a bit more explanation at 10:26, How hash is validated? Correct me: the decrypted hash from the received 'google-certificate' using public-key of root CA installed in browser is matched with the generated hash from public key present in the certificate?
Great video. When you say certificate hash data is encrypted using private key of issuer, does it mean that private is also sent along with certs? I am bit confused, why private key is being used to encrypt hash? Isn't public keys are used to encypt( as browser is doing with symmetric key) ? Or it is not neccesary to encrypt using public key always?
Thank you for that, I don’t have a 3-D printer as of yet, but I was looking at this as a way of getting my butt out of trouble when I am unable to reconstruct a burr puzzle correctly. Just need to learn a bit more how to get it all setup. Much appreciated.
It's a need past-time.. you can watch some of my earlier videos and you can make 1000s of puzzles if you have a 3d printer.. in fact.. if you buy puzzles, a 3d printer will pay for itself. Good luck and thanks for the comment.
The PCB comes from Professor Boots Skid Steer design at: github.com/ProfBoots. Look for the V2 of the Skid Steer. All STLs for my mods are at the Printables link in the Description above.
At around 12:00, in your class of Superbot, you directly reference three of their classes in the creation of the superbot... So I'm just learning and this is the part that I'm having trouble with. I thought a class wasn't supposed to reference other classes, but that makes it super difficult to do really simple things (in my example, I've made a nuclear power plant object, that when it is created it takes a certain amount of time to "power up" and then it creates a signal, which is a reference to another class, which is a no no). Is the proper way to use some sort of interface? Any advice is appreciated.
I'm not sure what you are asking. Port 80 is open on a server. A client sends a packet to port 80 on a server to get the web page. If the server closes port 80, the client can't reach the web page. A client does not "have" a port 80. They are reserved for web server.
@@ahmedabdelaziz7375 No.. you've missed the concept. Reserved ports are published on a list. They are used by servers. Because they are on a list, all clients know what ports to send their packets to for a particular service. So if I want to connect to an FTP service, I know to send it to a proper service, but to specify port 21, the well-known port for FTP. Clients cannot open/close ports on other machines. Let's say you have a Windows computer and you want to enable the TELNET service on it on port 23.. this allows a remote computer to connect to your computer and access. a command line. You now have port 23 "open" and you are listening on that port.. because you are now a Telnet Server. Only you.. the server can close port 23, shutting down the telnet service. A remote computer cannot do that.
Awesome instructions. What if you want to print a black cat with white eyes. How would we separate objects that aren't so square and on a perfect level? Do you have a tutorial vid for that?
Great explanation!! Thanks I have question, at 11:14 you mentioned that the public key from the ICA can be used to decrypt the hashed encrypted part from the NSCC certificate. Can a public key be used for decryption? I am still a little confused on this point.
Either key can be used to encrypt. But the *OTHER* key must be used to decrypt. Which key is used to encrypt depends on the application (digital signatures, encryption certs, etc). However, the private key is *ONLY* known to the person issued. It must never be distributed.
the problem I had was the connection to the temp/humidity sensor that was located under the bottom heating plate.. It was just too unreliable and I thought I fixed it later, but couldn't get it working and just thru it out and bought a PrintDry 3 which is great.. Could have been a broken wire, a really crapy small connector, or the sensor itself. But this is a huge point of failure in these units. Sunlu is likely one of the worst companies for support there is.. You can see that from reports on Web from people buying filaments and any other Sunlu products. Nice product when it works.. but zero support. Good luck with it. I don't think it actually needs a fan.. mine worked well because it was not really sealed.
Basically a user creates a PKI key pair. A public and private key. The public key can be sent to anyone.. and for large companies, their public keys may be included in an operating system. If I want to "sign" a document, I can encrypt, either a part of the document, or the whole document with my private key and send it to you. I can put my public key on Facebook, if I want. Anyone can get my public key. When you get the document that I sent, you try to decrypt it with my public key.. If you can, then you know I sent it. No one else can encrypt the document in a manner that allows you to use my public key to decrypt.
@@davecrabbe4579 so you encrypt the document itself, not a digest of it, or generate a hash and encrypt it (maybe combined with the other two options for integrity check?)
