Embedded Systems on PCB Isolation

Waterproof, Sound Proof Generator Enclosure

Sat, 14 Aug 2021 00:00:00 +0000

For RVs and vans, generators are very useful but very loud. I wanted an enclosure that is both waterproof and noise dampening. It’s hard to find something like this, because it’s not easy to encase an engine and keep it cool.

In the end, I failed to keep the generator cool enough to for more than 2 hours.

I used a Wen 56235i generator. It is a cheaper variant of the Honda EU2200 series.

How To Spot a Counterfeit or Refurbished Motorola Razr V3

Thu, 04 Apr 2019 00:00:00 +0000

Note - There are many versions of the Motorola Razr, each with subtle differences. Even similar version have differences between countries. Not all of the differences of this counterfeit/refurbished Razr will apply to your Razr!

This applies specifically to the Motorola Razr V3, but you can find similar discrepancies on a Razr V2 or V3i.

If you have a feeling the phone is fake, that’s a good indicator that it is.

Motorola Razr V3: Real vs Counterfeit Teardown

Sun, 31 Mar 2019 00:00:00 +0000

Left- Authentic Razr V3, Right - Counterfeit Razr V3

I recently bought a Razr V3 on eBay. The listing below shows that it is made by Motorola. The pictures are of an authentic Razr. However I received a counterfeit Razr.

PS - I wrote a quick guide on spotting counterfeit Motorola Razr V3’s (without disassembly).

If the phone would have worked, I wouldn’t have cared. But it wouldn’t get a signal with my SIM, so I complained and got a refund.

Why Typedef Is Used For Structs In C

Tue, 18 Oct 2016 00:00:00 +0000

At first glance, adding a typedef to a struct in C seems to complicate the definition. However, it simplifies the declaration of the structure. This is not always recommend, as it can add a layer of obfuscation.

Structures

Here is how a normal structure is defined in C.

#include <stdio.h>
#include <string.h>

struct Cat { // defining Cat structure
 char name[20]; // members of Cat structure
 int age;
 int weight;
};

int main() {
 struct Cat myCat; // declaring Cat structure, myCat

 strcpy( myCat.name, "Cleopatra"); // setting member values
 myCat.age = 4;
 myCat.weight = 10;

 return 0;

}

In the example above, notice declaring myCat on Line 11 is “struct Cats myCat”. We are about to see how typedef will shorten this.

Atmel ATtiny ATmega AVR Quick Code Reference

Wed, 28 Sep 2016 00:00:00 +0000

I usually forget bitwise operators, basic variables, and functions when coding in Atmel Studio for an ATtiny or ATmega project.

Normally, I look at some of my old code for reference. This is my focused and consolidated version of the important building blocks.

I/O Registers
Bitwise Operators
Delays
Interrupts
Program Memory
PWM

I/O Registers

DDRx - Data Direction Register - Configures each pin as an input or output. The 0th bit refers to the 0th pin of the port and the 7th bit refers to the 7th bit of the port.
PORTx - Data Register - The value of the pin, used for reading input or writing output
Pxn - The nth bit of port x. PB0 refers to the 0th bit of port B and PE7 refers to the 7th bit of port E.
x - letter (e.g. B, D, E, F, G)
n - number (0, 1, 2, … 7)

Note that you still should refer to the datasheet for the specifics on these registers and how to set their values.