When working with microcontrollers that require a factory calibrated osccal value stored in memory, it’s very normal that once in a while this setting could be lost during an upload of a new program or when accidentally erasing the device.
I’m no exception and erased many times this value by mistake in several devices. Once this value is erased, it’s not possible to recover it unless it was written on a sheet of paper or in our own memory and use it to record it back.
This project has the ability to calculate what is the appropriate osccal value for the 12F675 microcontroller.
OSCCAL Value Finder – [Link]
IR detectors are little microchips with a photocell that are tuned to listen to infrared light. They are almost always used for remote control detection – every TV and DVD player has one of these in the front to listen for the IR signal from the clicker. Inside the remote control is a matching IR LED, which emits IR pulses to tell the TV to turn on, off or change channels. IR light is not visible to the human eye, which means it takes a little more work to test a setup.
In this tutorial we will show how to:
Test your IR sensor to make sure its working
Read raw IR codes into a microcontroller
Create a camera intervalometer
Listen for ‘commands’ from a remote control on your microcontroller
IR remote receiver-decoder tutorial - [Link]
HD44780 based character LCDs require at least 6 I/O lines from microcontroller to display data. Therefore, they are not suitable for low-pin microcontrollers like PIC12F series microchips. In this project, I am going to show how to drive an HD44780 based LCD display with only 3 pins of a microcontroller. I am going to demonstrate it with PIC12F683 microchip. The character data and command from the microcontroller is transferred serially to a shift register (74HC595), and the parallel output from the shift register is fed to LCD pins.
3-Wire Serial LCD using a Shift Register - [Link]
This project shows how to build a GPIB to USB Converter named Pic-Plot2. With this unit you are able to obtain the screen plots of a GPIB instrument to the screen of a laptop without complex software, following this low cost solution. The interface is based on a PIC16F628 microcontroller and an FT23R chip. Check schematics and software on the link below. [via]
Pic-Plot2: GPIB to USB Converter – [Link]
This project is a box that is linked to a certain coordinate on earth. The challenge is to find this coordinate, in order to access the contents of the box. The GeoCache Box is based on a PIC18F2520 microcontroller that is interfaced to GPS receiver and it has a LCD and a lock. [via] Markus at jave.de writes:
Other than with ordinary GeoCaches you do not need to find the box at the target coordinate: You will already have it when the puzzle starts. But the box is closed and it will only open when you are near the target coordinate. In order to find the coordinate, the box has a button: When you press the button, the internal GPS receiver will detect the current location and the distance to the target will be displayed. Of course the number of trials is limited. If you press the button too often, the box will be sealed forever.
Little Reverse GeoCache - [Link]
This project shows how to build a temperature controlled soldering iron based on Atmega8 microcontroller. With this soldering iron you can set the desired temperature with two push buttons. Otherwise you can use three preset temperature buttons. Check schematic on the link below.
DIY Temperature Controlled Soldering Iron – [Link]
This tutorial will teach you how to use external and pin change interrupts on an AVR microcontroller. I will be using an ATmega168. The general principles apply to other AVR microcontrollers, but the specific vary greatly.
External Interrupts on an ATmega168 – [Link]
This is a new design of a tutorial board based on the popular PIC16F84A microcontroller. It features eight single leds, a 7-segment display, an LCD display and five push buttons. It is an ideal solution for the beginner to take his/her first programming steps in the world of microcontrollers. Having an in-circuit-programming (ICP) header, it can be easily reprogrammed without unplugging the microcontroller each time, provided that the programmer also supports this feature (like OziPic’er).
PlayPIC - [Link]
This board is a small controller board on which you can build your projects. It is suited for educational use, experiments or prototyping. The board uses the AT2313 microcontroller with a 10Mhz crystal. The board contains the ISP 10-pin connector for in circuit serial programming. It has also a push button reset switch for resetting the microcontroller. The I/O pins of the microcontroller are also available on two ML10 connectors for connecting for example the LCD-Interface board.
ATTiny2313 Board RS232 - [Link]