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Topic: (1) Homebrew Steel Rider Project - All In Fun |
Bob Lawrence
From:
Beaver Bank, Nova Scotia, Canada
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Posted 15 Aug 2009 5:44 pm |
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A few years back Mike Brewer (Texas) sent me a homemade MIDI pickup. I wired it up to the regular Steelrider Pickups and got it to trigger the Steel Rider unit. (on a few very basic tests) It may not have been perfect but it basically worked and is certainly worthy of further study. This winter I will use it with a homebrew set of pre-amps(10 string) that (I made some a few years ago but will have to make more).(they work great) Once I get both working together (reasonably well) I will try the next step "Pitch to MIDI conversion" I've already been studying various options/theorys for about 5 years. I've also tried pitch detection using a variety of methods but don't have anything working that's like the steel rider (in how it works) but I'm not out of ideas yet. It's time to try a few new things and put it all toghther. I will post the various stages, results and a variety of pictures as I go , for anyone that may be interested.
All In Fun:
The Steel Rider was created by a bunch of engineers over many years.I'm a computer tech by trade (I haven't even done that in about 10 years) and not an Engineer, so don't expect too much. 
Maybe it will get Dave Beaty from Telonics fired up and he'll make us a nice replacement unit for the Steel Rider. 
Last edited by Bob Lawrence on 21 Sep 2009 8:12 pm; edited 1 time in total |
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Bob Lawrence
From:
Beaver Bank, Nova Scotia, Canada
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Posted 15 Aug 2009 5:45 pm (2)Homebrew MIDI pickup - Mike Brewer
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Mike's homebrew pickup - Wired to a guitar preamp. It (basically) worked hooked into the Steel Rider. It's only working on 5 strings at this point. It was just a quick Proof of concept test.
Spare Coils for the New pickups
Picture of a (old) pickup coil(bottom Left) and 2 magnets (bottom right)The Canadian dime and the finger pick are used to illustrate the size in reference to know objects.
Last edited by Bob Lawrence on 21 Sep 2009 8:13 pm; edited 6 times in total |
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Bob Lawrence
From:
Beaver Bank, Nova Scotia, Canada
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Posted 15 Aug 2009 5:46 pm (3)Homebrew Steel Rider Preamps - Bob Lawrence
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To be updated later
Last edited by Bob Lawrence on 21 Sep 2009 8:13 pm; edited 2 times in total |
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Bob Lawrence
From:
Beaver Bank, Nova Scotia, Canada
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Posted 15 Aug 2009 5:47 pm (4)Pitch To MIDI Converter - Bob Lawrence
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Experimental board - TriBladeProp: Uses 3 Propeller ICs for a Single Board Computer (SBC) This board is divided into blades.(Blade 1, Blade 2 , Blade 3) Each blade allows a propeller chip to be mounted( I stuck in a few 40 pin sockets to show the locations).
It also has an area for the following if required:
RAM
Xtals,
EEPROMS
Voltage regulators
Micro SD card
FT232 - USB to a computer
Flash
I'll use this as part of the development stage to get all 3 propeller chips communicating for pitch detection, pitch to MIDI, MIDI out to a sound module etc. I still need another board for the AD converters, filters etc.
One of my winter projects is to decide what I need mounted on the board and to get it mounted,soldered and working.
To be updated later
Last edited by Bob Lawrence on 21 Sep 2009 8:14 pm; edited 6 times in total |
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Bob Lawrence
From:
Beaver Bank, Nova Scotia, Canada
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Posted 15 Aug 2009 5:50 pm (5)Microcontrollers - P8031AH -Vrs the Propeller chip
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(Microcontrollers - P8031AH -150 VRS Propeller chip - 80Mhz
Processing Power
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Old Way:
- P8031AH -150 - 8 bit, 15Mhz.
- 40 pin chip
- 1 Used for a Master Microcontroller
- 6 used for Slave Microcontrollers
Total microcontroller chips used = 7 (40 pin chips)
P8031AH Data-sheet
http://www.datasheetcatalog.org/datasheets/1150/502581_DS.pdf
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Modern Way: Propeller Chip
8 each * 386 individual Processors called Cogs running in parallel at 80Mhz
Two programming languages are available:
1) A High-level language called "Spin"
2)"Propeller Assembly" which can execute at up to 160 MIPS(for all 8 cogs) (20 MIPS - Million Instructions Per Second, per cog).
Note: Raw Power: Remember the power you had on your old 386 computer? This has the same processing power as 8 of them but they are all a part of a 40 pin chip and can run in parallel.
I could probably do everything with one chip but it's easier to design with at least two chips or maybe 3. That would be less than half the number of 40 pin chips required for the old version.
The Number of microcontroller chips required for the planned Design (3):
- 10 String Pitch converter unit: I would like to use a processor(COG) per string That would be 8 Cogs on one 40 pin chip + 2 in another for a 10 string unit. A third chip for all other functions.(see below)
- 12 string String Pitch converter unit: Still a processor(COG) per string = 8 in one chip and 4 in the other. A third chip for all other functions.(see below)
3rd chip: MIDI USART, LCD , Touch screen , SD media storage card etc.
Last edited by Bob Lawrence on 21 Sep 2009 8:16 pm; edited 9 times in total |
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Bob Lawrence
From:
Beaver Bank, Nova Scotia, Canada
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Posted 15 Aug 2009 5:51 pm (6)Steel Rider Theory of Operation - Overview
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Disclaimer: All of the information provided in the thread is provided for experimental and educational benefits only. It is subject to change at any time. There is no known theory of operation manual, guide etc available(to my knowledge) for the Steel rider. The information provided is based on a variety of sources such as schematics, manufacture data sheets, etc and observations. In some cases the specs can be confirmed from the part manufactures data.In other cases it's just an observation, educated guess or even a guess  . You may use the info provided at your own risk and verify it using your own methods.
10 String pre-amp output voltages:
1 and 6 = .3 Vpp
2 and 7 = .6 Vpp
3 and 8 = .7 Vpp
5 and 9 = 1.4 Vpp
6 and 10 = 1.5 Vpp
LOW PASS FILTERS (LPF):
- Each set of strings have a LPF with a specified cutoff frequency set with resistors.
- The purpose of the LPF is to the complexity of the signal by attenuation of the harmonic frequencies and leaving the fundamental frequency in tact.
- The LPF also Removes the high frequency component and minimizes a form of distortion known as aliasing (distortion) .This improves the signal for pitch analysis
Filter Specs:
- The filter uses a LM324 Op amp
- The LPF is a 3 pole filter.
- The LPF has 40db of attenuation.
Filter - Test Cutoff Frequency and Resistor chart( by string number)
String 1 - Frequency: 723 Hz - Resistor: 22K
String 2 - Frequency: 723 Hz - Resistor: 22K
String 3 - Frequency: 723 Hz - Resistor: 22K
String 4 - Frequency: 723 Hz - Resistor: 22K
String 5 - Frequency: 600 Hz - Resistor: 27K
String 6 - Frequency: 600 Hz - Resistor: 27K
String 7 - Frequency: 408 Hz - Resistor: 39K
String 8 - Frequency: 408 Hz - Resistor: 39K
String 9 - Frequency: 338 Hz - Resistor: 47K
String 10 - Frequency: 338 Hz - Resistor: 47K
String 11 - Frequency: 159 Hz - Resistor: 100K
String 12 - Frequency: 159 Hz - Resistor: 100K
GAIN CONTROL AMP:
- Controlled by the microcontroller
- 8 steps of gain by a factor of 2 for each step.
- Gain range : 2 to 256
- At the start of analysis the gain control amp is set at the max value.
- Path overview: [Filter] ->[gain control amp] --> [ADC] --> [analyze waveform] -> Determine Pitch -> Output MIDI note/s
ADC: Analog to digital conversion - ADC8031 (Complete Spec sheel is available from National.com)
- ADC8031 - 8 pin DIP - IC
- 8-bit successive approximation A/D converters with a serial I/O and configurable input multiplexers ( 8 bit) .The signal is represented by values ranging from 0 to 256.
- Serial I/O A/D Converters
- Sampeling Rate: must be twice (2X) the highest frequency component.
- 5 VDC voltage reference
- 0V to 5V input range with single 5V power supply
- ADC Data conversion time: 32 micro secs.
- Max Sample Rate:0.031 MSPS
- Max KSample Rate: 31 ksps
- Min Supply Voltage: 4.5 Volt
- Max Supply Voltage: 6.3 Volt
- Input Sample/Hold:No
- Temperature Min: -40 deg C
- Temperature Min: 85 deg C
- Low Power:15 mW
Last edited by Bob Lawrence on 4 Oct 2009 7:07 pm; edited 5 times in total |
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Bob Lawrence
From:
Beaver Bank, Nova Scotia, Canada
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Posted 15 Aug 2009 5:53 pm (7)EPROM 27C64A VRS EEPROM - SD Card or Memory Stick
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Both EPROM and EEPROM chips are used for storing programming code.
The Old EPROM:
- Erasable Read only memory. It wasn't electronically erasable like the one below(EEPROM). You have to use Ultraviolet light to erase it.Ultraviolet (UV) light has shorter wavelengths than visible light. Exposing the EPROM to the sun could do it over a few days.
The New EEPROM: (Electrically eraseable read only memory)
The old steel Rider used:
1 each - 27Cxx - 28 pin (Master EPROM)
6 each - 27Cxx - 28 pin (Slave EPROM's)
The Hombrew SteelRider will use:
1 EEPROM + maybe 1 SD Card for(not sure yet)
To be updated later
Last edited by Bob Lawrence on 21 Sep 2009 8:17 pm; edited 3 times in total |
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Bob Lawrence
From:
Beaver Bank, Nova Scotia, Canada
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Posted 15 Aug 2009 5:55 pm (8)ADC08031 AD Converter VRS 8 Channel modern AD
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The Old AD converter (analog to digital converter):ADC08031
- 8 bit resolution
- 2 channels per chip
- Serial I/O
ADC08031 spec sheet: http://www.national.com/ds/DC/ADC08031.pdf
These chips are obsolete so I'll look at others like such as the MCP3208 (below)
The New: Microchip MCP3208 - 2.7V 4-Channel/8-Channel 12-Bit A/D Converters with SPI™ Serial Interface. (two of these should do it for 10 and 12 channels, 1 channel per string)
- 12-bit resolution
- 8 channels per chip
- SPI serial interface
- 100 ksps max. sampling rate at VDD = 5V
- 50 ksps max. sampling rate at VDD = 2.7V
http://ww1.microchip.com/downloads/en/devicedoc/21298c.pdf
The old steel Rider used:
6 each - 2 channel - ADC's
The Hombrew SteelRider will use:
2 each - 8 channel ADC's
To be updated later
Last edited by Bob Lawrence on 21 Sep 2009 8:17 pm; edited 6 times in total |
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Bob Lawrence
From:
Beaver Bank, Nova Scotia, Canada
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Posted 15 Aug 2009 5:58 pm (9)MIDI USART 31.25 Kbps in Hardware Vrs a Software Version
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If a Microcontroller has a hardware USART it's easy to configure it 8 bits serial interface to 31250 bauds for MIDI .
The Propeller Chip doesn't have a hardware USART but you can use a cog and a serial (Spin) program to provide 31250 bauds for MIDI. I've tested this in the past and it woks well.
Last edited by Bob Lawrence on 21 Sep 2009 8:18 pm; edited 2 times in total |
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Bob Lawrence
From:
Beaver Bank, Nova Scotia, Canada
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Posted 15 Aug 2009 6:00 pm (10)Power Supply - 7805 5 volts DC vrs 3.3 volts DC
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Power adaptors:
Voltage regulators:
Current draw:
Heat:
3.3 Volt Regulator
The Propeller chip runs on 3.3 volts.
To be updated later
Last edited by Bob Lawrence on 21 Sep 2009 8:18 pm; edited 2 times in total |
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Bob Lawrence
From:
Beaver Bank, Nova Scotia, Canada
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Posted 15 Aug 2009 6:02 pm Physical size - Old VRS Modern technology
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| To be updated later |
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Bob Lawrence
From:
Beaver Bank, Nova Scotia, Canada
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Posted 15 Aug 2009 6:03 pm Speed - Old Vrs New Technology
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Xtal's - Clocking
Pushing the Propeller Chip to 100Mhz (80Mhz is recommended) with a 6.25Mhz external Xtal(overclocking)and a internal 16 X PLL (phase lock loop, built inside the chip)
16 * 6.25 = 100
Last edited by Bob Lawrence on 17 Aug 2009 8:53 pm; edited 4 times in total |
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Bob Lawrence
From:
Beaver Bank, Nova Scotia, Canada
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Posted 15 Aug 2009 6:05 pm Multiple gain amp - Old Vrs New
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| To be updated later. |
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Bob Lawrence
From:
Beaver Bank, Nova Scotia, Canada
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Posted 15 Aug 2009 6:07 pm LED's - LCD's
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| To Be updated later. |
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Bob Lawrence
From:
Beaver Bank, Nova Scotia, Canada
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Posted 15 Aug 2009 6:07 pm Buttons VRS Touch Screen
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| To be updated later |
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Bob Lawrence
From:
Beaver Bank, Nova Scotia, Canada
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Posted 15 Aug 2009 6:09 pm Design Log
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Just a quick log for updates as I go.
Last edited by Bob Lawrence on 13 Sep 2009 6:16 am; edited 2 times in total |
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Bob Lawrence
From:
Beaver Bank, Nova Scotia, Canada
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Posted 15 Aug 2009 6:10 pm YouTube - Video Demos
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Various demo videos to be added later to youtube
There no videos available at this time.
Last edited by Bob Lawrence on 13 Sep 2009 1:02 pm; edited 2 times in total |
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Bob Lawrence
From:
Beaver Bank, Nova Scotia, Canada
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Bob Lawrence
From:
Beaver Bank, Nova Scotia, Canada
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Posted 15 Aug 2009 6:40 pm Propeller Chip Based MIDI Sound Module
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Propeller Music Synthesizer:
Use a separate Propeller chip as a stand alone MIDI sound module. All done in software. Feed it with a Pitch to midi converter. It won't sound as good as a Roland XV2020 Sound Module but it will be acceptable sound for fun stuff.It will be modified version of a Propeller music synthesizer - written by Andy Schenk.
I will have to build a MIDI interface to hook to the pitch rider as well.
Propeller MIDI Player:
The same software core works as a standalone MIDI player that can play type 0 MIDI files from a SD card. I've played around with a version is this and it works great!
To be updated later.
Last edited by Bob Lawrence on 19 Aug 2009 4:51 pm; edited 3 times in total |
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Bob Lawrence
From:
Beaver Bank, Nova Scotia, Canada
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Posted 15 Aug 2009 6:55 pm
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Duplicate post removed
Last edited by Bob Lawrence on 25 Sep 2009 10:10 pm; edited 3 times in total |
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Bob Lawrence
From:
Beaver Bank, Nova Scotia, Canada
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Posted 19 Aug 2009 3:38 pm Re: Reference Material
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[quote="Bob Lawrence"]Book List
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Just a list of reference material that I found helpful in understanding the various modern technologies available (but the info may not be necessarily used) to design a complete unit.
Reference Books:
Musical Applications of Microprocessors - Hal Chamberlin
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The Scientist and Engineers Guide to Digital Signal Processing by Steven W. Smith
Free on-line Version: http://www.dspguide.com/
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Digital Signal Processing and the Microcontroller - Motorola University
Understanding Digital Signal Processing - Richard Lyons
Programming the 16-bit Microcontroller in C - Learning to Fly the PIC24 - Lucio Di Jasio
Embedded Design with the PIC18F452 Microcontroller
Maxium MIDI - Music Applications in C++ - Paul Messick
Active Filter Cookbook - Don Lancaster
The Active Filter Handbook - Frank P. Tedeschi
Practical Electronics Handbook - Ian Sinclair
The Circuit Designer's Companion - Tim Williams
Op Amps for Everyone - Texas Instruments - Ron Mancini.
Free on-line Version:
http://focus.ti.com/lit/an/slod006b/slod006b.pdf
Op Amp Applications Handbook - Analog Devices - Walt Jung
Operational Amplifiers - George Clayton , Steve Winder
Practical Electronics for Inventors - Paul Scherz
*********** Online Reference Material **************
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Microchip AN699: Anti-Aliasing, Analog Filters for Data Acquisition Systems (Author: Bonnie C. Baker)
http://ww1.microchip.com/downloads/en/AppNotes/00699b.pdf
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Agilent - Impedance Measurement Handbook
http://cp.literature.agilent.com/litweb/pdf/5950-3000.pdf
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Microchip - ADC Design Guide:
http://ww1.microchip.com/downloads/en/AppNotes/21841b.pdf
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Microchip - AN540 - Implementing IIR Digital Filters
http://ww1.microchip.com/downloads/en/AppNotes/00540c.pdf |
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Bob Lawrence
From:
Beaver Bank, Nova Scotia, Canada
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Posted 13 Sep 2009 7:13 am Step 1
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In Progress: Record steel guitar tones to a CD for testing: Oscilloscope analysis, FFT analysis, pitch detection trial and error etc.
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In Progress: Build a simple circuit board to Interface the old (Steel Rider analog to digital converter (ADC) ADC08031 to the modern Propeller Chip(Microcontroller):
Note: ADC is an electronic device that converts an input analog voltage (or current) to a digital number proportional to the magnitude of the voltage or current.
1) Use the test board To study the signal that the old steel rider was able to digitize. Also, study the noise level/s in the conversion.
2) Compare the ADC08031 with several modern AD converters and/or converter types such as:
a. Delta Sigma Converter - *oversampling method*
Interface directly with the Propeller chip using passive components(resistors & capacitors). Allow the counters in the Propeller chip to do the AD conversion.
Note 2: Given a particular fabrication process, a sigma-delta ADC can give more bits of resolution than any other ADC structure, with the only exception of the integrating ADC structure. Both kinds of ADC's use analog integrating amplifier to cancel out many kinds of noise and errors.
b. Microchip MCP3208 - *successive approximation method*
External ADC chip.
Note 3: A successive approximation ADC is a type of analog-to-digital converter that converts a continuous analog waveform into a discrete digital representation via a binary search through all possible quantization levels before finally converging upon a digital output for each conversion.
To Do:
- Make a simple schematic of the ADC test circuit.
_ Convert the schematic to a JPEG and post it to the web.
- Build test ADC circuit with software. Use a 10k pot and a computer serial terminal program for monitoring the test.
- Order Microchip MCP3208 sample chips
- Build a DAC (digital to analog) test circuit with software. This will allow the ADC signal to be re-constructed and displayed on a VGA monitor for analysis.
- Use the test tones CD to generate a few FFT patterns and monitor/record them on a oscilloscope.
- Convert the FFT to images (jpg) to allow posting to the web. |
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John Billings
From:
Ohio, USA
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Posted 13 Sep 2009 11:36 am
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Very interesting Bob! BTW, I didn't get anything at the youtube link.
JB |
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Bob Lawrence
From:
Beaver Bank, Nova Scotia, Canada
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Posted 13 Sep 2009 1:07 pm
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| John Billings wrote: |
Very interesting Bob! BTW, I didn't get anything at the youtube link.
JB |
@John:
Thanks! John. It's too early to add video's at this time. It's still very early in the baby steps design stages. I took out the youtube link so people don't get confused
"Various demo videos to be added later"
I will add pictures and screen shots as I go. I made the first schematic today. It's a simple tester for the old 0831ADC chip. Next step is to post the picture of the schematic and build the tester and get the software working. Then I can post some screen shots, of the results.
Last edited by Bob Lawrence on 13 Sep 2009 1:13 pm; edited 1 time in total |
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John Billings
From:
Ohio, USA
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Posted 13 Sep 2009 1:09 pm
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| Thanks for clearing that up Bob. Can't wait to see/hear some though! |
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