diff options
| author | Sadeep Madurange <sadeep@asciimx.com> | 2025-10-25 18:19:48 +0800 |
|---|---|---|
| committer | Sadeep Madurange <sadeep@asciimx.com> | 2025-10-25 19:07:22 +0800 |
| commit | 8cd867cd53794386cb9443bfc023fe97c5c5fa47 (patch) | |
| tree | 0f3f076e8b7f542b511d737eaaf3f3ec1cef457d /_site/archive/arduino-uno/index.html | |
| parent | 210a4c8671b368a3a240f9cb7a0bd1718a301523 (diff) | |
| download | www-8cd867cd53794386cb9443bfc023fe97c5c5fa47.tar.gz | |
Render posts.
Diffstat (limited to '_site/archive/arduino-uno/index.html')
| -rw-r--r-- | _site/archive/arduino-uno/index.html | 117 |
1 files changed, 117 insertions, 0 deletions
diff --git a/_site/archive/arduino-uno/index.html b/_site/archive/arduino-uno/index.html new file mode 100644 index 0000000..ff3ca44 --- /dev/null +++ b/_site/archive/arduino-uno/index.html @@ -0,0 +1,117 @@ +<!DOCTYPE html> +<html> + <head> + <meta charset="utf-8"> + <title>Notes on programming ATmega328P chips</title> + <head> +<meta charset="utf-8"> + <title>Notes on programming ATmega328P chips</title> + <link rel="stylesheet" href="/assets/css/main.css"> + <link rel="stylesheet" href="/assets/css/normalize.css"> + <link rel="stylesheet" href="/assets/css/skeleton.css"> +</head> + + + </head> + <body> + + <div class="container"> + <ul id="navlist" class="left"> + + <li > + <a href="/">hme</a> + </li> + <li > + <a href="/projects/">proj</a> + </li> + <li > + <a href="/about/">abt</a> + </li> + <li><a href="/feed.xml">rss</a></li> + </ul> +</div> + + + + <main> + <div class="container"> + <h2 class="brand center" id="title">NOTES ON PROGRAMMING ATMEGA328P CHIPS</h2> + + <h6 class="center">10 APRIL 2025</h5> + + <br> + + <div class="threecol 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> + +<h2 id="5-v---16-mhz-configuration">5 V - 16 MHz configuration</h2> + +<p>The steps that follow refer to the following pinout.</p> + +<table style="border: none; width: 100%;"> + <tr style="border: none;"> + <td style="border: none; width: 50%; vertical-align: top;"> + <img src="pinout.png" alt="Pinout" style="width: 100%" /> + <p style="text-align: center;">Pinout</p> + </td> + <td style="border: none; width: 50%; vertical-align: top;"> + <img src="breadboard.jpeg" alt="Circuit" style="width: 100%" /> + <p style="text-align: center;">Breadboard</p> + </td> + </tr> +</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 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 +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="33-v---8-mhz-configuration">3.3 V - 8 MHz 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> + +<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 +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>Burn the bootloader to the ATmega328P: + <ul> + <li>Select ‘ATmega328P (3.3 V, 8 MHz)’ 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 +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> + +<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 +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> + +</div> + + <p class="right italics">by W. D. Sadeep Madurange</p> + </div> + </main> + + </body> +</html> |