Tag Archives: mcu

External RAM and lost MCUCSR

Atmega’s MCUCSR status register gives info about restart reason like regular reset-pin shorted, watchdog initiated reset, or brown-out on low voltage from power supply. Pieces of valuable information for device defect tracking. Reading MCUCSR early in test program was fine, … Continue reading

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Pimp my bus: from 8-bit AVR to 32-bit ARM

Going to newer architecture is unevitable evolution. ARM series is particularly good choice as knowledge of its core functionality is to large extent portable across manufacturers. While ARM Cortex-M chips are close to 8-bit AVRs in footprint size and price … Continue reading

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Water Level Logger – insufficient RAM

For prototype I estimated that 128kB or flash would suffice and I was right; firmware took 75kB even though fatten up by embedded strings used across the code for tracing. On the other hand 4kB RAM of Atmega128 turned to … Continue reading

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FreeRTOS tickless idle on Atmega128

Real-time operating system (RTOS) makes embedded coding more elegant and maintainable if MCU has to take care of many things at the same time. FreeRTOS also supports many platform including  8-bit AVRs. I am using it because of both reasons. … Continue reading

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FreeRTOS on Atmega8?

How to compile FreeRTOS real-time operating system on 8-bit AVR microcontroller Atmega8? It is not supported out of the box as well as google hardly helps with that issue. I did some experiments and understood why people are not doing … Continue reading

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Rainbow glowing ping-pong

While I was finalizing e-snowflake project, I imagined that single RGB 5050 LED would create nice rainbow effect if placed inside a ball like ping-pong. You can find plenty of such projects on the net, this one was heading to … Continue reading

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e-snowflake

Late in December 2011 I almost bet that I am able to design & build myself a blinking serpent of rainbow lights for Christmas tree. I did not want to spend much time on creating cables and lights themselves but … Continue reading

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The die has been cast

I remember my first digital circuit made up when I was teenager, an electronic dice, made of TTL logical gates, driving 7 LEDs formed to display any combination of dots of thrown dice. I realized it would be good microcontroller … Continue reading

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