Skip to content

Commit

Permalink
Fixed "Flappy DAC" bug in rev.2.x.x firmware
Browse files Browse the repository at this point in the history
 - Fixed #26
  - Changed adjustment logic to be calculated based on Vcc rather than ADC reference, which was causing issues in the mathematical functions, resulting in negative number outputs
 - Migrated to internal vRef, fixed #23
 - Eliminated floats, fixing #31
  - This required addition of long, however
 - Fixed #20
  • Loading branch information
pyr0ball committed Jun 27, 2019
1 parent 1d098f1 commit f745940
Show file tree
Hide file tree
Showing 6 changed files with 578 additions and 310 deletions.
322 changes: 156 additions & 166 deletions firmware/AVR-Source/Pyr0_Piezo_Sensor_v2.x.x/Pyr0_Piezo_Sensor_v2.x.x.ino
Original file line number Diff line number Diff line change
@@ -1,166 +1,156 @@
/*
Piezoelectric Z-Axis sensor using AtMega88/168/328 (AtMega 48 doesnt have enough memory for this version)
This sketch reads a piezo element to detect a touch of the printer's nozzle to the bed.
The sense pin is tied to an interrupt, which is pulled high by internal pullup resistor.
When the piezo touches the bed, the amplification circuit will draw the interrupt pin low
and the atmega will output a pulse based on the programmed trigger duration
* PD2 INT0 (Piezo In 'D2')
* D7 PCINT23 (Trigger OUT 'D7')
* PC0 ADC0 (Voltage Reference Check 'A0')
* PC1 ADC1 (Sensitivity Adjustment Check 'A1')
* PD4 PCINT20 (Error feedback LED 'D4')
* PB6 PCINT6 (Voltage Adjustment Resistor 0 'D20')
* PB7 PCINT7 (Voltage Adjustment Resistor 1 'D21')
* PD5 T1 (Voltage Adjustment Resistor 2 'D5')
* PD6 PCINT22 (Voltage Adjustment Resistor 3 'D6')
* PB1 OC1A (Comparator VRef PWM Out 'D9')
* PD3 OC2B (Voltage Follower VRef PWM Out 'D3')
Schematics for this project can be found here: https://github.com/pyr0ball/pyr0piezo/tree/master/docs/Schematics
For Arduino IDE use MCUdude MiniCore: https://mcudude.github.io/MiniCore/package_MCUdude_MiniCore_index.json
created 2/18/2019
by Alan "pyr0ball" Weinstock
This code is in the public domain.
*/

/* To set the below parameters using serial input, use the following:
To change trigger active duration: TRG_D [integer for milliseconds]
To change gain factor: GAIN_F [integer for gain state - see note*]
To change ADC hysteresis value: HYST [integer]
To change sensor input pullup vRef low threshold: VADJ [float value]
To change comparator trigger high threshold: VCOMP [float value]
These commands should be wrapped in this format:
<CMD, INT, FLOAT>
You must include the unused variable for each instance.
Examples:
<GAIN_F, 3, 0.00>
<VADJ, 0, 2.35>
*Note for Gain Factor:
The gain STATE is representative of these values:
0 = 3x
1 = 3.5x
2 = 4.33x
3 = 6x
4 = 11x
*/

// Configurable settings:
int GAIN_FACTOR = 2; // Gain adjustment factor. 0=3x, 1=3.5x, 2=4.33x, 3=6x, 4=11x
#define InitCount 6 // Number of times to blink the LED on start
int LOOP_DUR = 50; // duration of time between ADC checks and other loop functions
int TRG_DUR = 20; // duration of the Z-axis pulse sent, in ms
#define senseThrs 1.85
#define compThrs 2.54

int Hyst = 20; // Hysteresis value for ADC measurements
#define Vin 5 // input reference voltage

/*------------------------------------------------------------*/

// Debug output toggle. Uncomment to enable
#define DEBUG true

// Headers, variables, and functions
#include "pP_pins.h"
#include "pP_volatile.h"
#include "pP_functions.h"
#include "pP_serial.h"

// i2c input toggle. Uncomment to enable
//#define I2C true
#ifdef I2C
#include "pP_i2c.h"
#endif

void setup() {
pinMode(TRG_OUT, OUTPUT); // declare the Trigger as as OUTPUT
pinMode(ERR_LED, OUTPUT);
pinMode(Z_TRG, INPUT_PULLUP); // declare z-sense input with pullup
pinMode(V_FOLLOW_PIN, INPUT);
pinMode(VCOMP_SENSE_PIN, INPUT);
pinMode(GADJ_R0, INPUT); // declare input to break pull to ground
pinMode(GADJ_R1, INPUT); // declare input to break pull to ground
pinMode(GADJ_R2, INPUT); // declare input to break pull to ground
pinMode(GADJ_R3, INPUT); // declare input to break pull to ground
Serial.begin(9600);

// Uncomment the following lines to use PCInt pins instead of hardware interrupt
//#include <PinChangeInterrupt.h>
//attachPCINT(digitalPinToPCINT(Z_TRG), pulse, FALLING);

// Uncomment the followoing line to use hardware interrupt pin
attachInterrupt(digitalPinToInterrupt(Z_TRG), pulse, FALLING);

Serial.println("Initializing Pyr0-Piezo Sensor...");

}


/*------------------------------------------------*/

void loop() {

// Blink LED's on init
if (BlinkCount > 0) {
BlinkState = !BlinkState;
digitalWrite(ERR_LED, BlinkState);
digitalWrite(TRG_OUT, BlinkState);
delay(LOOP_DUR);
--BlinkCount;
}

// Get Serial Input
serialInput();

// Set any new parameters from serial input
updateParams();

// Check voltage of first and second stages and compare against thresholds
VComp = analogRead(VCOMP_SENSE_PIN);
diffCompL = (VComp - compInt) - Hyst;
diffCompH = (compInt - VComp) - Hyst;

VAdj = analogRead(V_FOLLOW_PIN);
diffAdjL = (VAdj - senseInt) - Hyst;
diffAdjH = (senseInt - VAdj) - Hyst;


// Set the amplification gain factor
adjustGain();

// Voltage Follower adjustment
if (diffAdjL > 0 || diffAdjH > 0) {
adjustFollow();
}

// Voltage Comparator adjustment
if (diffCompL > 0 || diffCompH > 0) {
adjustComp();
}

// Alert the user that auto-calibration is ongoing
calibrateAlert();

// Check for error state
checkError();

// Reply with status
serialReply();

// Sets trigger output state to false after completing loop
delay(LOOP_DUR);
digitalWrite(TRG_OUT, HIGH);
sensorHReading = 0;
}
/*
Piezoelectric Z-Axis sensor using AtMega88/168/328 (AtMega 48 doesnt have enough memory for this version)
This sketch reads a piezo element to detect a touch of the printer's nozzle to the bed.
The sense pin is tied to an interrupt, which is pulled high by internal pullup resistor.
When the piezo touches the bed, the amplification circuit will draw the interrupt pin low
and the atmega will output a pulse based on the programmed trigger duration
* PD2 INT0 (Piezo In 'D2')
* D7 PCINT23 (Trigger OUT 'D7')
* PC0 ADC0 (Voltage Reference Check 'A0')
* PC1 ADC1 (Sensitivity Adjustment Check 'A1')
* PD4 PCINT20 (Error feedback LED 'D4')
* PB6 PCINT6 (Voltage Adjustment Resistor 0 'D20')
* PB7 PCINT7 (Voltage Adjustment Resistor 1 'D21')
* PD5 T1 (Voltage Adjustment Resistor 2 'D5')
* PD6 PCINT22 (Voltage Adjustment Resistor 3 'D6')
* PB1 OC1A (Comparator VRef PWM Out 'D9')
* PD3 OC2B (Voltage Follower VRef PWM Out 'D3')
Schematics for this project can be found here: https://github.com/pyr0ball/pyr0piezo/tree/master/docs/Schematics
For Arduino IDE use MCUdude MiniCore: https://mcudude.github.io/MiniCore/package_MCUdude_MiniCore_index.json
created 2/18/2019
by Alan "pyr0ball" Weinstock
This code is in the public domain.
*/

/* To set the below parameters using serial input, use the following:
To change trigger active duration: TRG_D [integer for milliseconds]
To change gain factor: GAIN_F [integer for gain state - see note*]
To change ADC hysteresis value: HYST [integer]
To change sensor input pullup vRef low threshold: VADJ [float value]
To change comparator trigger high threshold: VCOMP [float value]
These commands should be wrapped in this format:
<CMD, INT, FLOAT>
You must include the unused variable for each instance.
Examples:
<GAIN_F, 3, 0.00>
<VADJ, 0, 2.35>
*Note for Gain Factor:
The gain STATE is representative of these values:
0 = 3x
1 = 3.5x
2 = 4.33x
3 = 6x
4 = 11x
*/

// Configurable settings:
int GAIN_FACTOR = 2; // Gain adjustment factor. 0=3x, 1=3.5x, 2=4.33x, 3=6x, 4=11x
#define InitCount 6 // Number of times to blink the LED on start
int LOOP_DUR = 50; // duration of time between ADC checks and other loop functions
int TRG_DUR = 20; // duration of the Z-axis pulse sent, in ms
#define senseThrs 1450
#define compThrs 2850
int dAdjFac = 1; // adjustment divider. Higher number will cause the DAC output to adjust more slowly.
int Hyst = 20; // Hysteresis value for ADC measurements

/*------------------------------------------------------------*/

// Debug output toggle. Uncomment to enable
#define DEBUG true
//#define VERBOSE true

// Headers, variables, and functions
#include "pP_pins.h"
#include "pP_volatile.h"
#include "pP_function.h"
#include "pP_serial.h"

// i2c input toggle. Uncomment to enable
//#define I2C true
#ifdef I2C
#include "pP_i2c.h"
#endif

void setup() {
pinMode(TRG_OUT, OUTPUT); // declare the Trigger as as OUTPUT
pinMode(ERR_LED, OUTPUT);
pinMode(Z_TRG, INPUT_PULLUP); // declare z-sense input with pullup
pinMode(V_FOLLOW_PIN, INPUT);
pinMode(VCOMP_SENSE_PIN, INPUT);
pinMode(GADJ_R0, INPUT); // declare input to break pull to ground
pinMode(GADJ_R1, INPUT); // declare input to break pull to ground
pinMode(GADJ_R2, INPUT); // declare input to break pull to ground
pinMode(GADJ_R3, INPUT); // declare input to break pull to ground
Serial.begin(9600);

attachInterrupt(digitalPinToInterrupt(Z_TRG), pulse, FALLING);

Serial.println("Initializing Pyr0-Piezo Sensor...");

}


/*------------------------------------------------*/

void loop() {

// Blink LED's on init
if (BlinkCount > 0) {
BlinkState = !BlinkState;
digitalWrite(ERR_LED, BlinkState);
digitalWrite(TRG_OUT, BlinkState);
delay(LOOP_DUR);
--BlinkCount;
}

// Get Serial Input
serialInput();

// Set any new parameters from serial input
updateParams();

// Set the amplification gain factor
adjustGain();

// Check voltage of first and second stages and compare against thresholds
adjustVin();
VComp = analogRead(VCOMP_SENSE_PIN);
VAdj = analogRead(V_FOLLOW_PIN);

// Voltage Follower adjustment
if (VLast > Hyst || VLast < -Hyst) {
adjustFollow();
}

// Voltage Comparator adjustment
if (VLast > Hyst || VLast > -Hyst) {
adjustComp();
}

// Alert the user that auto-calibration is ongoing
calibrateAlert();

// Check for error state
checkError();

// Reply with status
serialReply();

// Sets trigger output state to false after completing loop
delay(LOOP_DUR);
digitalWrite(TRG_OUT, HIGH);
sensorHReading = 0;
}
Loading

0 comments on commit f745940

Please sign in to comment.