Puerto Rico (PR)

Peurto Rico (PR):

This is part of USA, even though people often confuse it as a another country. It's unincorporated U.S. territory (NOT a US state) and part of Caribbean islands. It is mostly Hispanic, so Spanish spoken. Any person in US who can travel within USA can travel to PR as PR is a domestic destination. It's known for it's beaches and historic cities. San Juan, the capital, and the only big city, is beautiful. SW flies to San Juan. Flights from Dallas/Houston to San Juan may be had for < $200 when on sale.

PR is financially a poor US territory, so cost of living is low. However due to tourists, costs are at par with states like Texas. Activities, hotels ($100/night), cars ($50/day)  rent for same price as in US. The whole island of PR can be driven from East to West in 2 hrs, and from north to south in 30 minutes. The shoreline of PR is only 500kms. So, if you wanted to drive along the shoreline of PR, you could do it all in a day and still spend some time on few of the beaches !! 

 


 

Lodging and Transportation:

Lodging: Individual people rent out their homes for really cheap, compared to hotels which can be very expensive, especially around San Juan.

I booked via Expedia.  It was $500 for 7 nights, i.e $70/night for a 2 bedroom house with Kitchen, etc. The place is OK for staying, but it's cheap and right in the center of San Juan. The host "Angel" lives on ground floor with his family and is very nice guy, who will accommodate your needs. Link => https://www.expedia.com/San-Juan-Hotels-Tidy-And-Cozy-Place-To-Stay

You can similar houses for similar price. Hotels may also be had for cheap, especially if you start moving away from central San Juan. Since driving to San Juan is so easy from anywhere in PR, I would advise to find some property really nice far away from SJ. It will cost you < $100/night for a big property.

Transportation: Rent your own car from the airport. My rental car was via Hertz, which had it's rental fleet right at the airport (walking distance, as it's right across the street). It cost $350 for a week during July. Having a car will allow you to drive anywhere. You don't need 4 Wheel drive, as I was able to drive almost everywhere with a 2 Wheel drive. But very few places might have a requirement for 4 wheel. Taking Uber, etc is just wastage of money.

For some reason, gas is cheap in PR ($0.75/Litre which is ~$3/gal, same price as in USA as of July 2025)

 


 

Top attractions:

A week of trip to PR will allow you to see almost everything. Beaches are the main attraction. Downtown old San Juan is also beautiful to just walk around. Below are top attractions:

  • Beaches: If you love beaches, PR is the place to go. There are 100's of world class beaches. Literally you could park your car anywhere on the shoreline, and you will most likely have a beach within walking distance. Each beach is different, and depending on your taste, one may be better than other. Best to explore as many beaches as you can.
  • Bio Luminescent bay:
  • Old San juan

 


 

UART

UART => Universal Asynchronous Receiver Transmitter

UART is widely used in microcontrollers, and other slow speed devices. It's as simple as it can get, as it's just 1 data line with no clk line. This is called half duplex, as only 1 side can send data. In full duplex, we have 2 data lines, one for transmitting and other for receiving.

 

Link => https://www.foxipex.com/2024/11/28/understanding-the-uart-protocol-a-comprehensive-overview/

 

 

Roofing repair: DIY

Roofing Repair : DIY

Roofing just like AC is one of the other dreaded DIY job. It's very expensive to repair (roofs costing > $20K to replace, usually $50K or so to get a good roof). Again you are dependent on the contractor to do a good job, and it's big money. A lot of companies may charge you less, but do shabby work with low quality material. You can never go just based on price. Also, there is no way to know the kind of work that the Roofing Company did.  Just like a AC repair, you will come to know about the quality of their work few years down the line.

There are lot of scalpers who will go home to home advertising "free roof inspections", and will immediately point to a lot of hail damage and other damages to the roof. Even for newly built houses, they will find "roof damage" and insist on fling a claim with your insurance. They will also say that they will cover your deductible, so that your out of pocket cost for replacing the roof is going to be $0. I never believe these guys. Most of the times, insurance won't even approve the replacement of roof. May be these scalpers are able to have a 10% success rate, but that's good enough for their business. Also, since they aren't charging you any money,  they will have to resort lowest quality material and shabby workmanship to still make a profit. Roof is an expensive repair, and if you aren't careful, ou might end up with a roof, which is worse than what was there before :(

Repairing a singlr damaged shingle: Remeber that shingles are put in overlapping layers, where one 3 ft shingle has 2 shingles on top in a layerd fashion. We have 4-6 nails on our damaged shingle right under the first shingle on top of it, and then another 4-6 nails on our damaged shingle right under the second shingle on top of it. Only when we remove both layers of nails (Total 8-12 nails), we can remove the damaged shingle.

Vid on replacing single architectural shingle => https://www.youtube.com/watch?v=O1lXsXM2E4c

 

San Antonio, TX

San Antonio, TX

Below is the map for various attractions in San Antonio TX, USA:

Dallas, TX (FIXME)

San Antonio is the 2nd most populous city in TX right behind Houston, with population of 1.5M as of 2024. It's bigger than Dallas and  Austin, which is surprising, since San Antonio never gets any mention.

There are few attractions in Dallas that warrant a trip.

  • Six flags and Hurricane Harbor => It's a big theme park with both regular park and water park combined in one. Season pass can be had for cheap ($60-$70) during labor day sale. See under "shopping" section (Kids activities sub section) for deals.
  • River walk => Other big attraction right in downtown

 


 

Restaurants: I'll mostly be listing Indian restaurants. As always, restaurants food quality changes from time to time, so be sure to check out latest reviews. What I list below as a good quality restaurant may not be so anymore.

  • Lion Indian Cuisine => Limited menu for vegetarian items, but very delicious food. Tried "paneer butter masala", "Malai Kofta" and Naan. All were very good. They have a $15 off of $45+ purchase certificate on restaurant.com (as of June, 2025).
  •   abc

 


 
 
 
 

Calculus

Calculus:

We'll start with limits and then move to differentials and integrals.

Limits:

Limits are one of the easiest to master. They form the basis of calculus. When we say limit, we are trying to find the value of a function, as it approaches a particular value of a variable.

ex; Y= 2*x+5.