Standalone ATmega: Running without the Arduino Board
📥 RESOURCES & DOWNLOADS
• ISP Connection Slides: https://drive.google.com/file/d/1H5tZ...
• Arduino ISP: https://docs.arduino.cc/built-in-exam...
• Fuse Calculators
– AVR® Fuse Calculator: https://www.engbedded.com/fusecalc/
– AVR Fuse Calculator by Frank Zhao: http://eleccelerator.com/fusecalc/fus...
• Programming the Arduino Bootloader: https://learn.adafruit.com/ftdi-frien...
• Burning the Bootloader without external AVR-Writer: https://make.kosakalab.com/arduino/bo...
✏️ EXERCISES
• Standalone ATmega: https://drive.google.com/drive/folder...
🧠 QUIZ
https://forms.gle/GG7SQEbp5pQWrwso8
Have you ever wanted to deploy your ATmega project without the bulky Arduino board? In this comprehensive section, we explore how to extract the ATmega328P chip from the Arduino and run it standalone with minimal external components. You will learn about power supply requirements, clock options including internal oscillators, fuse programming, and In-System Programming (ISP) for programming chips outside the Arduino environment.
We begin by examining what the Arduino board provides: power supply (USB or 7-20V DC converted to 5V via 7805 regulator), USB-to-UART converter (FTDI232) for programming, 16MHz crystal oscillator with 22pF capacitors, reset button with pull-up resistor, pin headers, and status LEDs. For deployment, many of these are unnecessary - the ATmega itself is remarkably small.
Power supply requirements are covered: the ATmega328P operates from 1.8V to 5.5V (absolute maximum 6V). Battery options include 2-4 AA cells, CR2032 coin cell (3V), or LiPo (3.7V nominal). Important: clock frequency depends on voltage - 20MHz requires 4.5V+, while 3V limits operation to about 12MHz. Battery safety, especially for Lithium cells (thermal runaway risk), is emphasized.
The minimal standalone circuit requires: VCC and AVCC connected to power (with optional 10uH inductor and 100nF capacitor filter for ADC accuracy), GND connections, and a 10kOhm pull-up resistor on RESET to prevent accidental resets. A button to ground enables manual reset.
Clock options are explored in detail: the external 16MHz crystal (with 22pF capacitors) can be replaced by internal oscillators - the calibrated 8MHz RC oscillator or the ultra-low-power 128kHz oscillator. Using internal oscillators eliminates the need for external components, simplifying the design and reducing power consumption.
Fuse programming is explained: fuses are non-volatile configuration bits that cannot be changed by software during normal operation. The low fuse (LFUSE) controls clock selection (CKSEL bits), clock division (CKDIV8), clock output (CKOUT), and start-up time (SUT bits). Critical warning: incorrect fuse settings can make the ATmega unresponsive - only high-voltage programmers can recover from some mistakes.
ISP/ICSP (In-System/In-Circuit Serial Programming) enables programming without the bootloader using SPI protocol: MOSI, MISO, SCK, RESET, VCC, and GND connections. An Arduino can serve as an ISP programmer using the ArduinoISP sketch. A 10uF capacitor between RESET and GND on the programmer prevents auto-reset during programming.
Online fuse calculators simplify the confusing fuse bit notation (0=programmed, 1=unprogrammed). The avrdude command with "-U lfuse:w:0xe2:m" programs the low fuse directly. Never use "-F" flag to skip signature check - if communication fails, fuse programming will fail too.
#Arduino #ATmega #Standalone #ISP #ICSP #FuseProgramming #InternalOscillator #LowPower #BatteryPowered #EmbeddedSystems #avrdude #ArduinoISP #CKSEL #PowerSupply #MinimalCircuit
📖 CHAPTERS
0:00 Introduction
1:42 Components of an Arduino Board
6:26 The Power Supply and Batteries
10:10 Voltage and Frequency
11:13 Connecting the Power Supply and RESET
13:04 The external Clock Source
14:03 Internal Clock Sources
15:08 The Low Fuse: Clock Source Selection and Start Up Time
19:44 How to program Fuses (ISP/ICSP)?
21:59 AVRISP (Soft Programmers)
29:03 Programming Fuses with AVRDude
31:23 Calculating Fuse Values
35:17 Practical Example: Programming Fuses
38:43 Development Steps
41:44 The FTDI232RL as ISP for Self-Programming
45:30 Summary and What's next?