A pull-up resistor is a resistor connected between a signal conductor (GPIO) and a positive power supply voltage while a pull-down resistor is a resistor connected between a signal conductor and a ground. They are used on inputs to prevent floating lines, rapidly switching between high and low and a middle “undefined” region. Outputs normally do … Read more
This is a simple ATtiny13 project that controls LED RGB using Software PWM. In result It gives really nice and colourful light effect. In our circuit a LED cathodes are connected to PB0, PB1 and PB2 while common anode is connected to VCC. The code is on Github, click here. Parts Required ATtiny13 – i.e. … Read more
Yet another quick how-to guide of making a minimalist development board for AVR. The MBAVR-4 development board is designed for megaAVR MCUs like Atmega16 and Atmega32. It is a 4th and last project in series of MBAVR family home-made boards in order to create an nice environment for rapid development. I did these all things … Read more
This is another quick how-to guide of making a minimalist development board for AVR. This time is about MBAVR-3 development board designed for megaAVR MCUs like ATmega8, ATmega88, ATmega168 or ATmega328. It is a 3rd project in series of MBAVR familly home-made boards in order to create an nice environment for rapid development. I did … Read more
This is a quick how-to guide of making a minimalist development boards for MCU of tinyAVR, like ATiny2313 or ATiny4313. MBAVR-2 is a second project in series of MBAVR family home-made boards in order to create an nice environment for rapid development. All I did, I did at home. I used toner transfer technique for … Read more
Serial peripheral interface (SPI) is a hardware/software communication protocol originally developed by Motorola and widely used by others in the industry. SPI is quite straightforward – it defines how to communicate in easy way between 2 digital devices – i.e. between AVR and devices, like other AVRs, external EEPROMs, DACs, ADCs, etc. SPI is a single-master … Read more
Yet another ATtiny13 blinky project. In our circuit a LED is connected to PB0 and it is made to blink for roughly every second by using Watchdog Timer. The code is on Github, click here. Parts Required ATtiny13 – i.e. MBAVR-1 development board Resistor – 220Ω, see LED Resistor Calculator LED Circuit Diagram Firmware This … Read more
Since ATtiny13 does not have hardware USART/UART in some cases we’re forced to use Software UART. In this example project a simple bit-banging UART has been presented. Compiled for both TX and RX it uses just 248 bytes of flash. Default serial configuration is 8/N/1 format at 19200 baud (lowest error rates during tests). It … Read more
Yet another blinky project that is based on internal timer. In our circuit a LED is connected to PB0 and it is made to blink for roughly every second by using timer OVF (overflow). The code is on Github, click here. Parts Required ATtiny13 – i.e. MBAVR-1 development board Resistor – 220Ω, see LED Resistor … Read more
This Project simply flashes the LED in random manner. It uses PRNG (Pseudo Random Number Generator) based on LFSR (Linear Feedback Shift Register) to generate 16-bit (pseudo) random numbers. The less significant bit of randomly generated number is a major factor in decision to on/off the LED. The code is on Github, click here See … Read more