This document discusses building a development board for an ATMega8 microcontroller that functions as a simple oscilloscope. It outlines meeting specifications, minimizing costs, and completing the project in the shortest time as the core engineering values. It provides the specifications for the oscilloscope, discusses using AVR microcontroller features to implement it, and lists the tools needed including an AVR compiler and programmer. Circuits for a function generator and integrating the oscilloscope with a Python console are presented. The document emphasizes applying knowledge from school to implementation and building your own tools.

1. Make Your Own
Development Board
ATMega8 series for example
StarNight @ 2014.4.21 JuluOSDev

2. After sharing
Simple Scheduler
@ OSDC.tw 2014,
it is a good chance to talk
about the hardware
implementation of
Simple Osilloscope

3. 1. 符合規格 (Highest Order)
Meet the specification.
2. 最小成本
Smallest cost.
3. 最短完成時間
Finish it in shortest time.
by 王迺慤老師
工程師的三個核心價值
Boundary
Conditions!!!

4. Lessons Learned from PMP (Partial)
● Initiating
○ Develop project charter
● Planning
○ Collect requirements
○ Define scope
○ Plan Quality
○ Estimate costs
○ Develop schedule
● Excuting
● Monitoring & controlling
● Closing
The specification going
to be met.
Find the smallest cost.
Find the shortest time.

5. The Specification of osilloscope
● Signal range: 0 ~ 5V
● Sampling frequency: 100 Hz
● Sampling channels: 6 ~ 8 channels
● Connects to computer with UART
● Communication protocal: Modbus

6. 學校作業通常是從定義域
去找值域，但工程師要做
的是從值域去找定義域。
Students’ homework is a practice which finds
the f(x) from x. However, engineers’ work is
a problem which finds the x from f(x).
by 王迺慤老師

7. The Cost and Time
● I can use:
○ The ADC channels of AVR.
○ The timer of AVR for periodic sampling.
○ The USART function of AVR.
● I can buy an AVR with the money that I can
afford.
● I am familiar with AVR, which shorts
development time.
● There are open source resource for AVR,
ex: toolchain, programmer ...

8. Read Datasheet
Reference from: ATmega328 datasheet

9. Build a development board
That will be an oscilloscope.
https://github.com/starnight/ATmega328-Board

11. Tools
● Toolchain:
avr-gcc
● Libc:
avr-libc
● Downloader/Uploader:
avrdude
● Prgrammer:
USBtinyISP, USBasp ...

12. I flashed
Simple Oscilloscope
firmware into the
development board.
https://github.com/starnight/Simple-Oscilloscope

13. Function Generator for Signals
Schmitt Trigger Integrator
Could reference: http://www.pcbheaven.com/circuitpages/Triangle_Wave_Generator/

14. Function Generator

15. Oscilloscope Console by python + pyserial + matplotlib

16. All Circuits Analysis Begins with
● On - Off
● For a resistor:
v(t) = i(t) × r(t)
● For a capacitor:
q(t) = C(t) × v(t)
● For an inductor:
v(t) = d ( L(t) × i(t) ) / dt

17. Lessons Learned from
Oscilloscope
Nyquist Frequency / Aliasing
http://en.wikipedia.org/wiki/Aliasing

18. 學校教了我們很多東西，
而我們應要知道，如何將
這些知識應用在實做，
而不只是封存在腦袋中。
We need to integrate the knowledge learned
from school and use it when implementation.

19. Build your own tools ~
That’s maker !!!!!
自己的國家自己救！
自己的工具自己做！

20. Thank you and Q & A
https://github.com/starnight/ATmega328-Board