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Saturday 21 May 2016

Watchdog Resets

There are two commands which can help prevent a watchdog reset.

  1. delay()
  2. yield()

These commands allow the ESP8266 to perform internal routines while the user commands are waiting for some action. If the internal routines are not executed on time the watchdog is triggered.

Simple Ping Example

There are instances where you want to check if the ESP8266 is connected to a Wifi AP and if the AP does have internet connectivity or not. In those situations try the code below

#include <ESP8266WiFi.h>
#include <ESP8266Ping.h>

const char* ssid     = "ssid";
const char* password = "password";

void setup() {

  // We start by connecting to a WiFi network

  Serial.print("Connecting to ");
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
/* If you are here you successfully connected to your access point */

  Serial.println("WiFi connected");  
  Serial.println("IP address: ");

void loop() {
  Serial.print("Pinging ip ");

  if("")) {
    Serial.println("Success!!"); /* if the code reaches here you are good to go */
  } else {
    Serial.println("Error :(");

Stable ESP8266 experiences

After struggling to get the ESP8266 ESP-012 to work without reboots, watchdog resets and lots of unknown problems I finally seem to have successfully managed to get the ESP8266 work without reboots. The circuit uses 10K ohm resistors from VCC to Rst, En, GPIO0 and from GND to GPIO15. Also, if you plan on using the deepSleep option its best to short Rst to GPIO16 for the ESP8266 to wake up successfully. Also I used a massive 4700uF 25V capacitor as that's what I had lying around across VCC and Gnd but there have been multiple documented instances where 2200uF works fine.

I have been using a linear LM1117 3.3V regulator but plan on trying out TC1262-3.3VAB, or LF33ABV some day.

I blew a lot of these ESP8266 because I was using a 12V battery charger which was giving some fancy waveforms in the output. I opted out of this and botched a usb charger cable to hook to the LM1117's input. The power source was a 5V battery backup pack rated at 4000 mah.

Tuesday 29 July 2014

Hello World

Hello World - First entry in Gandi. Time to import all my old posts from my dead site.

Tuesday 30 September 2008

Code maintainence for SQR

In order to fix code many a times one needs to search for terms, function names, defect/case ID's etc in SQR/SQC/INC (henceforth referred to as SQR files) files.

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Sunday 28 September 2008

Java and Excel

Interfacing Java with Microsoft Excel has always been a pain for software engineers.

The Apache foundation came out wit POI a Java API To Access Microsoft Format Files

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Tuesday 23 September 2008

XAMPP a boon for PHP/MySql developers

An web development requires a server configuration.

If the configuration also involves a database server it adds up to the complexity

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Sunday 21 September 2008

Making PHP work with Lighty (LightTPD)

Yes I know there are numerous articles and forums out there which talk about this.

Why am I writing about this again?

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Friday 22 August 2008

Application Engine and Command Line

More often than not I had situations where I needed to literally step through the application engine looking at the sections

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Tuesday 22 April 2008

Object Types in PeopleSoft

If you are wondering what Object Types are they are nothing but your usual objects that you create through the application designer or the PIA.

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Monday 21 April 2008

Hello PeopleSoft

In this section I will be sharing some gyan that I have about this beautiful ERP package called PeopleSoft.

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PeopleSoft Project Secrets

I had always wondered how does peoplesoft store projects created through the application designer

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Application Engine and Run Control ID's

Many a times I have heard people new to PeopleSoft say that one cannot

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Friday 10 August 2007

Apache HTTP Server (2.2.4) + Tomcat 5.5.23 + SSL

Tomcat with Apache HTTP server is a very common configuration for getting a J2EE application up and running. Though Tomcat is not a complete J2EE server

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Thursday 9 August 2007

Database accessing local files using CLR integration

Given below is a way to access the file contents of a database server using the latest feature of SQL Server 2005 called CLR integration.

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Wednesday 4 July 2007

Split a field in an SQL table

Many a times there are situations when you want to split a string in a field based on a separator like a comma(",") or maybe

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Sunday 27 May 2007

NSE Stock Updater

Download daily (bhavcopy) NSE quotes

Here's a small program which downloads daily NSE quotes or in other words the bhavcopy

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Create An Executable JAR

All JAR files contain something called a manifest file which holds information Java wants to know. One piece of information a manifest file

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Wednesday 18 April 2007

Java and Zip files

Unzipping Files with

The Java core packages include jave.util.zi

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