Pitch CV to Frequency Conversion with Offset Opamp and ADC

As a follow on from the previous post, another (related) way of converting a pitch CV signal to a frequency value is to offset any negative voltages, and then divide the pitch CV signal and then measure the voltage. In this case, a Teensy LC is used.

This method makes a few assumptions:
• That pitch CV signals may be unipolar, with negative voltages and positive voltages
• A user can set the offset via a pot, thereby having a variable range in terms of negative and positive voltages
• The pitch CV signal will be 1 volt per octave
• The pitch CV signal will be roughly a 10v range

12V and -12V power supply rails are required. In this case, the Digilent PowerBrick supplies both from USB 5V. A Eurorack power supply could also deliver 12V and -12V.

The pitch CV signal is summed with an offset voltage. The offset voltage is derived by dividing +12v to -12v with a 10k potentiometer. The sum of both signals is fed into an inverting opamp with unity gain, whose output is fed into a second inverting opamp. The resulting signal is a phase-correct unipolar pitch CV signal (assuming the 10k potentiometer is set correctly) in the range of perhaps 0V to 10V.

This signal is then divided by 3 by using a resistor voltage divider, where 20k is on the input side and 10k goes to ground – this will then equate to 1/3V per octave. The output of this voltage divider is then fed through some clamping diodes (such as 1n4148), to limit the range to 0V – 3.3V. The voltage is then read as a 12-bit analog to digital value.

The value range of the ADC conversion is 0 – 4095, and this represents a voltage range of 0V – 3.3V, which in turn represents a pitch range of 0 to 9.9 octaves (at 1/3V per octave) with a resolution of about 2.9 cents.

The ADC conversion value is mapped to MIDI pitch, giving a range of 120 – 132 semitones. This MIDI note value is then converted to frequency using my Arduino mtof library, which can be downloaded here.

The frequency value could be used to control another synthesiser or oscillator, or used for analysis and further conversion.

In this particular example, the resulting frequency value is sent via two MIDI pitch messages – one for the integer portion and one for the floating portion – and then reconstructed as a frequency value for a sine wave in a Max patch. A comparison can then be made to the analog output of a VCO to see how accurate the pitch conversion is. Note that a scaler value of 1.03 corrects for tuning issues – this value may change depending on setup.

#include <mtof.h>
#include <math.h>

float data;
float pitch;
float pitch_offset = 0;
float freq;

float max_voltage_of_adc = 3.3;
float voltage_division_ratio = 0.3333333333333;
float notes_per_octave = 12;
float volts_per_octave = 1;
float scaler = 1.03;

float mapping_upper_limit = (max_voltage_of_adc / voltage_division_ratio) * notes_per_octave * volts_per_octave * scaler;

void setup() {
analogReadResolution(12); // 12-bit ADC resolution
}

void loop() {
data = analogRead(0); // read pitch CV as data value using ADC
pitch = pitch_offset + map(data, 0.0, 4095.0, 0.0, mapping_upper_limit); // convert pitch CV data value to a MIDI note number
freq = mtof.toFrequency(pitch); // convert MIDI note number to frequency

/* To test out the frequency values that are being generated from pitch cv conversion, the frequency value is sent over MIDI pitch bend.
   * Pitch bend channel 1 is used for the integer component, and pitch bend channel 2 is used for the float component
   * The pitch bend messages are re-constituted in a Max patch for testing.
   * The pitch bend messages are not intended for use with a 'normal' MIDI synth
   * This is because they used as a way of conveying the data and not as a regular pitch bend message.
  */

usbMIDI.sendPitchBend(freq, 1); // split up integer part of the frequency and send as a pitch bend value
usbMIDI.sendPitchBend(fmod(freq, 1.0) * 10000.0, 2);

delay(1);
}

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Pitch CV to Frequency Conversion via Voltage Division and ADC

One simple way of converting a pitch CV signal to a frequency value is to divide the pitch CV signal and then measure the voltage. In this case, a Teensy LC is used.

This method makes a few assumptions:
• That a voltage of 0V is equal to MIDI note 36
• That all pitch CV signals will unipolar, with negative voltages being clamped to 0V
• The pitch CV signal will be 1 volt per octave
• The pitch CV signal will be roughly in the range of 0 – 9.9V

The pitch CV signal is divided by 3 by using a resistor voltage divider, where 20k is on the input side and 10k goes to ground – this will then equate to 1/3V per octave. The output of this voltage divider is then fed through some clamping diodes (such as 1n4148), to limit the range to 0V – 3.3V. The voltage is then read as a 12-bit analog to digital value.

The value range of the ADC conversion is 0 – 4095, and this represents a voltage range of 0V – 3.3V, which in turn represents a pitch range of 0 to 9.9 octaves (at 1/3V per octave) with a resolution of about 2.9 cents.

The ADC conversion value is mapped to MIDI pitch, giving a range of 118.8 semitones. This MIDI note value is then converted to frequency using my Arduino mtof library, which can be downloaded here.

The frequency value could be used to control another synthesiser or oscillator, or used for analysis and further conversion.

In this particular example, the resulting frequency value is sent via two MIDI pitch messages – one for the integer portion and one for the floating portion – and then reconstructed as a frequency value for a sine wave in a Max patch. A comparison can then be made to the analog output of a VCO to see how accurate the pitch conversion is.

#include <mtof.h>
#include <math.h>

float data;
float pitch;
float pitch_offset = 36;
float freq;

float max_voltage_of_adc = 3.3;
float voltage_division_ratio = 0.3333333333333;
float notes_per_octave = 12;
float volts_per_octave = 1;

float mapping_upper_limit = (max_voltage_of_adc / voltage_division_ratio) * notes_per_octave * volts_per_octave;

void setup() {
analogReadResolution(12); // 12-bit ADC resolution
}

void loop() {
data = analogRead(0); // read pitch CV as data value using ADC
pitch = pitch_offset + map(data, 0.0, 4095.0, 0.0, mapping_upper_limit); // convert pitch CV data value to a MIDI note number
freq = mtof.toFrequency(pitch); // convert MIDI note number to frequency

/* To test out the frequency values that are being generated from pitch cv conversion, the frequency value is sent over MIDI pitch bend.
   * Pitch bend channel 1 is used for the integer component, and pitch bend channel 2 is used for the float component
   * The pitch bend messages are re-constituted in a Max patch for testing.
   * The pitch bend messages are not intended for use with a 'normal' MIDI synth
   * This is because they used as a way of conveying the data and not as a regular pitch bend message.
  */

usbMIDI.sendPitchBend(freq, 1); // split up integer part of the frequency and send as a pitch bend value
usbMIDI.sendPitchBend(fmod(freq, 1.0) * 10000.0, 2);

delay(1);
}

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POP TOYS 1/6th scale Saint Knight — Charge version / Triumph version / War horse Preview

The Messenger: The Story of Joan of Arc is a 1999 French epic historical drama film directed by Luc Besson. The film stars Milla Jovovich, John Malkovich, Faye Dunaway and Dustin Hoffman. The Messenger portrays the story of St. Joan of Arc, the French war heroine and religious martyr of the 15th century. The story begins with young Joan as she witnesses the atrocities of the English against her family, and she is portrayed as having visions that inspire her to lead the French in battle against the occupying English forces. Her success in routing the English allows Charles VII to take the throne. Eventually Joan is captured by the English, tried and executed for heresy.

Pop Toys has released official pictures of their 1/6th scale Saint Knight inspired by Milla Jovovich in The Messenger: The Story of Joan of Arc. They are releasing two versions – Charge version and Triumph version – to make us drool. They have even included a War horse for good measure. And these are looking real good.

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POPTOYS EX019-A 1/6th scale Saint Knight Charge version Parts List: Female head with rooted hair, Short hairstyle head, Female body, Hands x4 (two outstretched steel hands + two holding steel hands)

Clothes/costume: Brown cotton, Brown pants, Upper hauberk, Helmet, Gorget, Plate armor, Arm armor, Cuisse, Dark leather armed belt, Dark leather belt

Weapon: Flag, Flagpole, Cross sword, Scabbard. Other accessories: Black bracket. Note: 80 percent of metal and PVC

POPTOYS EX019-B 1/6th scale Saint Knight Triumph version Parts List: Female head with rooted hair, Short hairstyle head, Female body, Hands x4 (two outstretched steel hands + two holding steel hands)

Clothes: Blue shirt, Brown pants, Upper hauberk, Helmet, Gorget, Plate armor, Arm armor, Cuisse, Dark leather armed belt, Dark leather belt

Weapon: Flag, Flagpole, Cross sword, Scabbard. Other accessories: Black bracket. Note: 80 percent of metal and PVC

POPTOYS EX019-C 1/6th scale Saint Knight — War horse Parts List: White war horse, Silvery horse helmet, Silvery horse breastplate, Brown leather cloth, Leather saddle and harness

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Hot Toys 1/6th scale Han Solo Collectible Figure (Deluxe Version) from Solo: A Star Wars Story

“I’ve waited a long time for a shot like this.” – Han Solo

The newest chapter of the Star Wars saga is unfolding in the upcoming Solo: A Star Wars Story! Fans will finally learn the past of the galaxy’s most beloved scoundrel – Han Solo.

Times were tough under Imperial rule. Han, a street thief, worked for a notorious gang on Corellia, stealing goods and cutting deals on behalf of an ill-tempered crime boss. Through a series of daring escapades deep within a dark and dangerous criminal underworld, Han Solo meets his mighty future copilot Chewbacca and encounters the notorious gambler Lando Calrissian, in a journey that will set the course of one of the Star Wars saga’s most unlikely heroes.

In celebration of the release of Solo: A Star Wars Story, Hot Toys is very excited today to introduce the brand new Deluxe Version 1/6th scale collectible figures of young Han Solo from the new film!

The highly-accurate collectible figure is specially crafted based on the appearance of Han Solo from Solo: A Star Wars Story. It features a newly developed head sculpt with striking likeness, a meticulously tailored outfit with brown-colored suede-like jacket, the iconic blaster pistol, an assortments of accessories including the symbolic gold-colored lucky dice, a wristwatch, a communicator and a specially designed figure stand.

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Hot Toys MMS492 1/6th scale Han Solo Collectible Figure (Deluxe Version) specially features: Newly developed head sculpt with authentic and detailed likeness of Alden Ehrenreich as Han Solo in Solo: A Star Wars Story | Movie-accurate facial expression with detailed skin texture | Brown color short hair sculpture | Approximately 31 cm tall Body with over 30 points of articulations | interchangeable hair sculpture with magnetic feature for wearing snow goggles*** | Three (3) pieces of interchangeable hands including: pair of relaxed hands, right hand for holding weapon | Four (4) pieces of brown-colored interchangeable gloved hands including: pair of relaxed gloved hands, right hand for holding weapon, gesturing left hand | Three (3) pieces of dark brown-colored interchangeable gloved hands including:*** pair of relaxed hands***, right hand for holding weapon***

Costume: grayish blue and black- colored V-neck shirt, brown-colored suede-like jacket, dark brown-colored leather-like belt, brown-colored leather-like blaster holster belt, dark blue-colored pants, black-colored boots with weathering effect, dark brown-colored mink-like overcoat with brown suede-like inner-layered jacket***, beige-colored scarf***

Weapon: blaster pistol

The Deluxe Version will exclusively feature Han Solo’s outfit on the planet of Vandor including a pair of goggles, a fur overcoat, and a climbing belt!

Accessory: pair of metallic gold-colored lucky dice, watch, communicator, wearable snow goggles***, climbing belt***, Interchangeable graphic cards for figure stand***, Specially designed figure stand with Star Wars logo and character nameplate

*** Exclusive to Deluxe Version

Release date: Approximately Q2 – Q3, 2019

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Mezco Toyz One:12 Collective 1/12th scale Logan 16cm tall action figure Preview Pics

Soldier • Weapon • Mutant

The One:12 Collective Logan figure invokes his rugged and feral nature. He features three head portraits, a cowboy hat, a dog tag, a fitted tank-top with jeans, a belt with a western-style buckle, a leather-like jacket with a functional zipper, and cowboy boots. Logan comes with six interchangeable hands – both with and without his trademark claws extended.

Born James Howlett, Logan was one of the most prolific X-Men before his tenure as Wolverine came to an end. Now in search of a quieter life, Logan must face the limited nature of his regenerative abilities while also coming to the aid of those who need his help.

Mezco Toyz One:12 Collective 1/12th scale Logan features: Three (3) head portraits, Approximately 16cm tall One:12 Collective body with over 30 points of articulation, Six (6) interchangeable hands: pair of fists, pair of clawed fists, pair of posing hands, Hand painted authentic detailing

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Costume: Tailored tank-top, Belt with western-style buckle, Jeans, Leather-like jacket, Cowboy boots

Accessories: dog tag, One:12 Collective display base with logo, One:12 Collective adjustable display post

Related posts:
Hot Toys 1/6th scale Hugh Jackman as Logan / Wolverine 12-inch action figure review on my toy blog HERE, HERE and HERE
Review of Hot Toys MMS264 “X-Men: Days of Future Past” 1/6th Wolverine 12-inch Figure posted HERE and HERE
Comparison pictures of various 1:6 scale Wolverine figures from the different X-Men films (pics HERE)

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Good Smile Company Figma Batman Ninja: DX Sengoku Edition 6.3-inch action figure Preview

“No Batmobile or Batwing… but I still have this body.”

From the anime film “Batman Ninja” comes a figma of Batman Ninja himself!

Good Smile Company Figma Batman Ninja: DX Sengoku Edition action figure is 6.3-inch (16cm) tall. The smooth yet posable figma joints allow you to act out a variety of action scenes. His cape is made from fabric and also features bendable parts allowing for various situations. He comes with two face plates including a glaring expression and a powerful shouting expression. Optional parts include two swords, a bat kunai and throwing effect parts for the bat kunai.

The DX Sengoku Edition also includes the armor parts to recreate Sengoku Batman as well as crossed arm parts. An articulated figma stand is included to facilitate various poses.

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TBLeague (formerly Phicen Ltd) 1/6th scale Cowgirl 12" Action Figure (Chloë Grace Moretz)

“Yeehaw Cowgirl!”

Chloë Grace Moretz was Hit Girl in Kick-Ass 1 & 2 but I certainly don’t remember seeing her in WestWorld or any other Western films. But still, TBLeague (formerly Phicen Ltd) has managed to come up with a 1/6th scale Chloë Grace Moretz as a Wild West CowGirl figure sans (without) her clothes since that’s how fantasy female figures should look like – totally unrealistic and implausible!

TBLeague (formerly Phicen Ltd) PL2018-103 1/6th scale Cowgirl 12-inch Action Figure Packing list: head sculpt, TBLeague female seamless body with metal skeleton, 3 pairs interchangeable hands with half-fingered gloves, Chest guard, belt with bullet decoration, necklace, armlet for right arm, knee armors, boots with feet, 2 × revolvers with holsters, dagger with sheath, shotgun, hat, rope, bottom, 2 × trouser legs, sleeves

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And in a related post, check out Kumik 1/6th scale Chloë Grace Moretz head sculpt Review posted on my toy blog HERE

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