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diff --git a/_site/archive/arduino-uno/index.html b/_site/archive/arduino-uno/index.html index 0c233c5..7509267 100644 --- a/_site/archive/arduino-uno/index.html +++ b/_site/archive/arduino-uno/index.html @@ -43,10 +43,10 @@ <h2 class="center" id="title">PROGRAMMING ATMEGA328P CHIPS</h2> <h6 class="center">10 APRIL 2025</h5> <br> - <div class="twocol justify"><p>This post is a step-by-step guide for wiring up ATmega328P ICs to run at 5 V -with a 16 MHz crystal and 3.3 V with an 8 MHz crystal. While the 5 V -configuration is common, the 3.3 V configuration can be advantageous in -low-power applications and when interfacing with parts that run at 3.3 V.</p> + <div class="twocol justify"><p>This post is a step-by-step guide for wiring up ATmega328P ICs to run at 5V +with a 16MHz crystal and 3.3V with an 8MHz crystal. While the 5V +configuration is common, the 3.3V configuration can be advantageous in +low-power applications and when interfacing with parts that run at 3.3V.</p> <h2 id="5v-16mhz-configuration">5V-16MHz configuration</h2> @@ -66,46 +66,46 @@ low-power applications and when interfacing with parts that run at 3.3 V.</p> </table> <ol> - <li>Connect pin 1 to 5 V via a 10 kΩ resistor.</li> - <li>Connect a 16 MHz crystal oscillator across pins 9 and 10.</li> - <li>Connect each pin of the crystal to ground via 22 pF capacitors.</li> - <li>Connect pins 7, 20, and 21 to 5 V.</li> + <li>Connect pin 1 to 5V via a 10kΩ resistor.</li> + <li>Connect a 16MHz crystal oscillator across pins 9 and 10.</li> + <li>Connect each pin of the crystal to ground via 22pF capacitors.</li> + <li>Connect pins 7, 20, and 21 to 5V.</li> <li>Connect pins 8 and 22 to ground.</li> </ol> -<p>In addition to the connections described above, it’s a good idea to add 0.1 μF +<p>In addition to the connections described above, it’s a good idea to add 0.1μF decoupling capacitors between pins 7, 20, and 21 and ground. <a href="Makefile">Here’s</a> a sample Makefile for avr-gcc and avrdude.</p> <h2 id="33v-8mhz-configuration">3.3V-8MHz configuration</h2> <p>The following steps use Arduino Uno as an ISP and Arduino utilities to program -ATmega328P’s bootloader and the fuses (e.g., BOD level) for a 3.3 V supply.</p> +ATmega328P’s bootloader and the fuses (e.g., BOD level) for a 3.3V supply.</p> <ol> <li>Upload the ‘ArduinoISP’ sketch to the Uno.</li> - <li>Wire up the ATmega328P as described in the previous section. Replace the 5 V -supply with a 3.3 V supply and use an 8 MHz crystal instead of the 16 MHz + <li>Wire up the ATmega328P as described in the previous section. Replace the 5V +supply with a 3.3V supply and use an 8MHz crystal instead of the 16MHz crystal.</li> <li>Connect the SPI ports (SCK, MISO, and MOSI) of the two MCUs.</li> <li>Connect Uno’s SS pin to the IC’s pin 1 (RESET).</li> - <li>The IC can be powered by the Arduino Uno’s 5 V pin.</li> + <li>The IC can be powered by the Arduino Uno’s 5V pin.</li> <li>Burn the bootloader to the ATmega328P: <ul> - <li>Select ‘ATmega328P (3.3 V, 8 MHz)’ from Tools > Processor.</li> + <li>Select ‘ATmega328P (3.3V, 8MHz)’ from Tools > Processor.</li> <li>Select ‘Arduino as ISP’ from Tools > Programmer.</li> <li>Select Tools > Burn Bootloader.</li> </ul> </li> </ol> -<p>The ATmega328P is now ready to run at 8 MHz with a 3.3 V power supply. You can +<p>The ATmega328P is now ready to run at 8MHz with a 3.3V power supply. You can upload programs to the ATmega328P as you usually would using avrdude. <a href="3v3.Makefile">Here’s</a> a sample Makefile with adjusted parameters (e.g., baud -rate) for an 8 MHz clock.</p> +rate) for an 8MHz clock.</p> <p>In both configurations, if you intend to use the ATmega328P’s analog-to-digital -converter with the internal 1.1 V or AV<sub>cc</sub> voltage as reference, do +converter with the internal 1.1V or AV<sub>cc</sub> voltage as reference, do not connect AREF (pin 21) to V<sub>cc</sub>. Refer to section 23.5.2 ADC Voltage Reference in the datasheet for more information.</p> |