Category: Informational

Pulse Width Modulation

MicroControllers are digital devices and usually do not have built in digital to analog converters (or DACs) to output an analog signal. Some, however, do have analog input. For digital output, the voltage is one of two values. Output voltage is either 0 volts or near equal to the voltage source (‘off’ or ‘on’). Using a technique …

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PIC Timer0 Code Generator and Calculator

PicKit2 PIC12F675

I needed an easy way to calculate Microchip PIC timer 0 values, so I created the PIC Timer0 Code Generator and Calculator.  If you are not familiar with PIC timers, there is a handy tutorial HERE. The calculator part, is a spreadsheet which calculates the timings and timer 0 frequency counter needed, given the  required …

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Controlling Things Based on Light Intensity

PIC12F683 with LDR

A PhotoCell or LDR (Light Dependent Resistor), used in a circuit, allows controlling things based on light intensity. Here is a circuit showing how to wire an LDR and demonstrates how controlling things based on light intensity is possible with a little help from a microcontroller. The thing being controlled in this circuit is simply an …

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How to keep an ENC28J60 Module from Freezing

ENC28J60 LAN Module

The ENC28J60 module is good for attaching an Arduino to a LAN or the Internet. The one real problem in doing so is how to keep an ENC28J60 module from freezing. No, not temperature wise ! 🙄  (‘Freezing’ in the sense of locking up, stop working, etc.) There are many Ethernet  arduino libraries for the …

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Switching 12V from a 5V Arduino

Switch 12V

I built a circuit to allow switching 12V from a 5V Arduino. Here is the wiring diagram and a picture of the actual circuit:         Get the Fritzing source HERE.  The side with two connections attaches to the 12V device being switched ON/OFF. The side with three  connectors,  connects to the 12V …

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Decoding an ESP8266 Firmware Image

ESP8266 Flash Tool on Windows

I recently coded a Python script for Decoding an ESP8266 Firmware Image. It’s the first part of my quest to create a Linux tool for creating a single flash image. More specifically, the script will decode a single binary image or a ‘combined’ image. A combined image (single flash image) can be created with the …

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12V to 5V Sensor Circuit

12V to 5V Sensor Circuit with DHT11

A number of sensors are powered via 12 Volts. Some, however, need 5 Volts.  To power a remote DHT11 temperature sensor, I created a 12V to 5V sensor circuit. This is the wiring diagram: Get the Fritzing code for it HERE.       The DHT11 needs 5 volts,  ground and data. It plugs into …

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4 Character 7 Segment Display

4 Character 7 Segment Display

I built another handy circuit to ‘house’ a 4 character 7 segment display. It looks like this: Basically it just ‘breaks out’ the 16 pins of the display with two 8 pin female headers. Pins 1-8 are connected to the header at the bottom and pins 9-16 are connected to the header at the top. …

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ESP8266 DIY Programmer Cradle

ESP8266 In Cradle

If you have been reading my posts lately, you will notice that I have been working a lot with the ESP8266 wireless module. To make it easier to work with, I made an ESP8266 DIY Programmer Cradle. Here is what it looks like (without and with the ESP8266 plugged in):           …

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MicroPython WebREPL on Android

MicroPython WebREPL on Android

I created an app (apk) to run MicroPython WebREPL on Android. Imagine you have your ESP8266 (with the MicroPython firmware) in some location where the only access to it is via a wireless connection. If you need to access and change/control it, you will need WebREPL. Of course, a wireless enabled laptop would get access …

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