Scope creep. It's the dead of every single project.

Still I let it seep into my design.

Because I received something that I enjoy spending time on.



And yes. The date is wrong in the picture above. One of my kids has already removed May 13 to read the joke on the backside..

Photo 12-05-15 16 01 49.jpg





The Digilent / Texas Instruments Analog Shield


Loads of fun to be had! This educational board has analog goodies on it.

And since my (not really mine) turntable is all analog, I feel that there's a good mix in the making.


My dream is to build something cool with this board mounted on the Atmel SAMA5D4 Xplained Ultra.

Whatever that may be.

It is possible that the end result has little relation to my submitted idea, but I'll take that as a plus .


Why this scope creep?

In my work life, I steer away from scope creep as much as I can. But this is not work.

In this design contest, I want to have plain fun. But I also want to do something relevant.

I've been struggling to find good use for the SAMA5D4. I know it's a great platform. And I had great plans for it.

But I also realize that I won't fully tame it within the timelines for this project. I won't be able to use it to its full capacity.

But I got myself to some level. I can compile my own c++ linux code.

My first idea after I realized my skill gap with the board was to replicate the light organ and servo motor part of my design on the SAMA5D4.

But that's sad, isn't it? If the only thing you can do with the Xplained Ultra is replicating something that the Arduino UNO with an ATMEL ATMega does just fine?


And that's where the Analog Shield comes in handy. It allows me to do something new.

And to learn something new, and to get a purpose for the SAMA5D4.

It's not going to be rocket science, but a part of my personal (publicly shared ) learning track.


What's on the Shield


It's a mix of Analog to Digital, Digital to Analog, and power supply circuits.

I'm going to focus on the ADC first. It's a 16 bit converter with four channels. And it supports SPI.

I'll do 'something' with my audio signal and that ADC converter.

If I have success, I'll have a look at the DAC. That one is also 16 bit with 4 channels.


At the moment I have no idea for the two power supplies. Both can go positive and negative.

One is fixed +/- 5V. The other one is variable +/-7.5V.


1. Analog to Digital Converter (ADC) Header

2. Digital to Analog Converter (DAC) Header

3. Power Header

4. Voltage Select Jumper

5. Variable Voltage Potentiometer





The only promise I make at this point is that I'll do my best to make something interesting out of it. And that I'll share success + failure on the blog.



Table of Contents
Chapter 1: Fix the turntable
1: Perpetuum Ebner Musical 1
2: A Time to Kill and a Time to Heal
3: Preparation for Motor Drive
4: Motor control with Infineon Motor Shield and Arduino UNO
5: Turntable speed sample testbed with Arduino UNO
6: Turntable Speed Sensor design
7: Control Theory - End of Chapter 1
Chapter 2: First Enchantments
8: Digital Light Organ Enchantment
9: Autonomous Servo Lift
10: SMD Time - Solder the IR Speed Sensor PCB
11: Yelp - who can Help me to Compile and Run my First SAMA5D4 C Program
12: Son et Lumiere - End of Chapter 2
Chapter 3: Taming the Board
13: Breakthrough - Run my own C++ Program on the SAMA5D4
14: Digital Light Organ Input Buffer
15: SAMA5D4 Blinky
16: Scope Creep
17: Audio Sampling with 16-bit ADC ADS8343
18: Sending Files to SAMA5D4 over USB
19: Port my Light Organ from Arduino to SAMA5D4
20: Fast Fourier Transform on the SAMA5D4 - End of Chapter 3
Epilogue: Reaching for the Clouds
21: Right-Sizing my Plans
22: My Own C++ Buffered Sampler on the SAMA5D4
23: Building In the Motorized Light Organ
24: Up to the Clouds with Yún
25: Publish or Perish
26: Turntable Finished
Stretch & Boni
Bonus 1a: Remote Light Organ with WiFI pt. 1
Bonus 1b: Remote Light Organ with WiFI pt. 2
Grande Finale: Paho MQTT Client on the SAMA5D4
Related blog
Vintage Turntable repair: Can I fix a Perpetuum Ebner from 1958
Review 1: Atmel SMART SAMA5D4 Xplained Ultra Unboxing and First Steps
Review 2: Atmel SMART SAMA5D4 Xplained Ultra - Building the Libraries from Source
Review 3: Digital Continuous Rotation (360°) Servo Part 1
Review 4: Digital Continuous Rotation (360°) Servo Part 2
Review 5: Atmel SMART SAMA5D4 Xplained Ultra - TCP/IP running
Review 6: Atmel SMART SAMA5D4 Xplained Ultra - LINUX Distro with SSH support
Enchanted Objects: Let's work together to tame the ATMEL SMART SAMA5D4 Xplained Ultra kit
17 bis: Off South...
Review 7: Atmel SMART SAMA5D4 Xplained Ultra - C++ ADC Example on Linux
Review 8: Atmel SMART SAMA5D4 Xplained Ultra - Product Review
Review 9a: Atmel SMART SAMA5D4 Xplained Ultra - Set up ADC Buffer with Hardware Trigger Part 1
Review 9b: Atmel SMART SAMA5D4 Xplained Ultra - Set up ADC Buffer with Hardware Trigger Part 2
Review 10: Atmel SMART SAMA5D4 Xplained Ultra - New Content on AT91.com
1958 Turntable from the Black Forest - Summary of the Enchanted Player Story