This project shows how to build a Digital clock with 32×8 LED matrix display based on ATmega168 microcontroller. It doesn’t use a RTC timer chip but timer interrupt triggered via external crystal at 32.678kHz. It allows generating exact 1sec intervals while AVR is running with internal system clock at 8MHz.
Digital clock with 32×8 LED matrix display – [Link]
This tutorial will teach you about the 8 and 16 bit timers on an ATmega168 microcontroller. Because the ATmega168 is very similar to the ATmega48, ATmega88 and ATmega328, the examples should also work on these. For other AVR microcontrollers the general principles will apply but the specifics may vary.
Timer interrupts on an ATmega168 – [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]
In this tutorial learn how to use Maxim DS1307 Real Time Clock with an ATMega168 AVR microcontroller to build your own multi featured LCD clock.
Using Maxim DS1307 Real Time Clock with Atmel AVR – [Link]
A common challenge when working with embedded systems is keeping track of real time. Luckily, most microcontrollers have timers that can be used with a precision quartz crystal — already present for the CPU clock — to keep track of real time. In this video tutorial, we show how you can use the timer interrupts on an ATMega168 chip to make a simple timer. Building off of this, it is possible to make your own reasonably accurate alarm clock, create systems to perform timed automated tasks, or create a multitude of other projects.
Crystal Real Time Clock – [Link]
Running out of space in your big Arduino project? Good news! Finally, after months of backorders, one can now buy the latest improvement to the ‘ATmega8′ line of chips: the ATmega328’s.The ‘328 has 32K of flash, and 2K of SRAM. Basically its got the capacity of an ATmega32 but in a slimmer package. These chips are notable for their ability to drop-in replace the ATmega168. So that means if you have an Arduino or compatible clone, it is a easy 2 minute swap.
I’ve merged my previous updates to the Arduino bootloader to the most recent release and also fixed 2 annoying bugs that have prevailed this long. (1. the missing signature bytes when using the bootloader directly and 2. the broken EEPROM code). Download the ‘328-compatible bootloader files here.
There are 250 preprogrammed chips are in the Adafruit webshop or you can get blank chips from Mouser (but be warned that they’re backordered till mid-December)
Upgrade your Arduino projects – [Link]
This device monitors household power usage and logs it to an SD card. A simple analog front-end amplifies the signals from voltage and current detectors and an ATmega168 microcontroller computes the power consumption using the formula P=V*I. The voltage and current are each sampled at 9615 Hz so the integration should be fairly accurate even for highly non-sinusoidal loads such as computers or fluorescent bulbs. A graphical LCD shows the power usage as a strip chart and can also act as an oscilloscope to display the voltage and current waveforms. The current is amplified in three stages (1x, 10x, and 100x) so that different gains can be used giving accurate readings for both high and low power usage. [via]
An AVR-based power usage logger – [Link]