ATtiny841

Watchout for duplicate pins for the same port! The ATtiny841 has TXD0 and RXD0 duplicated and the bootloader will only work for one pair! Programming Using USBasp For no crystal internal osc and 5V VCC we used these settings: Programming using USBasp and Arduino ICD “Burn bootloader” gave a confusing single message about setting SCK […]

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.Programmers General

Getting an AT / ATtiny microcontroller ready for serial port Arduino programming To be able to program using just the serial port pins you need your AT/ATtiny to first be programmed with a bootloader, as has been done on the microcontroller fitted on an Arduino manufactured PCB. Programmers There are many, we’ve used successfully USBasp […]

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Uploading never ends

Will typically be caused by something bad in your program but a way to force it to complete so you can troubleshoot what is happening is to press the Arduino reset button as soon as you see “Compiling sketch” change to “Uploading…” as you program the Arduino. Possible causes we’ve come across wdt if used, […]

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ATmega328 speed

Instruction speed Arduino uses a 16 MHz oscillator. Instruction clock is 16Mhz = 62.5nS per instruction. How long do instructions take to process? Generally instructions that operate on registers take one cycle, instructions that operate on memory take two cycles, and “special” instructions take 3 cycles. Look at the data sheet for more details

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ATmega32u4 speed

Instruction speed Arduino uses a 16 MHz oscillator. Instruction clock is 16Mhz = 62.5nS per instruction. How long do instructions take to process? Generally instructions that operate on registers take one cycle, instructions that operate on memory take two cycles, and “special” instructions take 3 cycles. Look at the data sheet for more details

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Conversion Time

ATmega32u4 A conversion takes 13 ADC clocks. The ADC clock needs to be set using a prescaller from the main OSC to give an acceptable ADC clock rate. To get the full 10 bits of resolution The successive approximation circuitry requires an input clock frequency between 50kHz to 200kHz. Faster with 10bit resolution Setting the […]

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Serial Port Programming

Programming an Arduino using the serial port Generally the Tools > Programmer selection is only used for Tools > Burn Bootloader and Sketch > Upload Using Programmer and is not used for standard uploads. “Programmer” setting For standard uploads you can set Tools > Programmer to anything you like because it will have no effect. […]

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