Hello all,
I'm trying to do the project of an Ultrasonic Flow Meter with TDC-GP22 using Arduino UNO. I used the library of leokoppel with a simple code to do the test:
#include "GP22.h"
#include <SPI.h>
#include <avr/io.h>
/*
*
* Test setup (Arduino Uno, through 5->3.3V level shift)
* 10 -> SS
* 11 -> MOSI
* 12 -> MISO
* 13 -> SCK
* 2 -> INT
* 5V -> VCC
* GND -> GND
* 4 -> DS18B20 temperature sensor (optional)
*/
const bool DEBUG = 1;
const int FAST_MODE = 1;
const int PIN_INT = 2;
GP22 tdc(PIN_INT, DEBUG);
float cycleFactor_ns = 0;
void setup() {
Serial.begin(115200);
Serial.println("Go !");
tdc.init();
tdc.writeRegister(0, CFG_KEEP_DEFAULT_BITMASKS[0]
| CFG0_ANZ_FIRE_START_2*1 // Fire 20 (4)+16
| CFG0_DIV_FIRE_1*1
| CFG0_DIV_FIRE_0*1 // Fire divided by 4
| CFG0_DIV_CLKHS_0*0 // Clock divided by 1
| CFG0_START_CLKHS_START_1 * 1 // Setting time 480µs
| CFG0_CALIBRATE * 1 // Calibration on
| CFG0_MESSB2 * 1 // Measurement mode 2
| CFG0_ANZ_PORT //Modification with temperature(not used yet)
| CFG0_TCYCLE
| CFG0_ANZ_FAKE
| CFG0_SEL_ECLK_TMP
| 0x00
);
tdc.writeRegister(1, CFG_KEEP_DEFAULT_BITMASKS[1]
| CFG1_HIT1_0 * 1 // Calculate 1st Stop Ch1 - Start
| CFG1_HIT2_1 * 1
| CFG1_HITIN1_2 * 1 // Wait for 4 hit on channel 1
| CFG1_HITIN2_1 * 0 // Wait for 0 hits on channel 2
| CFG1_SEL_START_FIRE * 1
| CFG1_EN_FAST_INIT * 0
| 0x00
);
tdc.writeRegister(2, CFG_KEEP_DEFAULT_BITMASKS[2]
| CFG2_RFEDGE1 * 0 // Ch 1 sensitive to one edge
| CFG2_EN_INT_ALU // Enable interrupt on ALU ready
| CFG2_EN_INT_TDC_TIMEOUT // Enable interrupt on TDC timeout
| CFG2_DELVAL1_12 // DELVAL1= 5000
| CFG2_DELVAL1_9
| CFG2_DELVAL1_8
| CFG2_DELVAL1_7
| CFG2_DELVAL1_3
| 0x00
);
tdc.writeRegister(3, CFG_KEEP_DEFAULT_BITMASKS[3]
| CFG3_EN_AUTOCALC_MB2 // Automatic calculation of all enabled hits(mode 2 only)
| CFG3_EN_FIRST_WAVE // Automatic first hit detection
| CFG3_SEL_TIMO_MB2_1 // Predivider for timeout = 1024µs
| CFG3_DELVAL2_15 // 10 periods after first hit for 3rd stop
| CFG3_DELVAL2_13
| CFG3_DELVAL2_9 // 9 periods for 2nd stop
| CFG3_DELVAL2_6
| CFG3_DELVAL2_3 // 8 periods for 1st stop
| 0x00
);
tdc.writeRegister(4, CFG_KEEP_DEFAULT_BITMASKS[4]
| CFG4_KEEP_DEFAULT_2 * 0
| CFG4_KEEP_DEFAULT_1 * 1
| CFG4_DELVAL3_8 * 0 // Enable pulse width measurement
| CFG4_DELVAL3_7 * 0 // Rising edge
| CFG4_DELVAL3_6 // Additional offset shift by +20mv
| CFG4_DELVAL3_5 * 0 // No offset -20mv
| 0x00
);
tdc.writeRegister(5, CFG_KEEP_DEFAULT_BITMASKS[5]
| CFG5_CON_FIRE_1 // Enable output fire up
);
tdc.writeRegister(6, CFG_KEEP_DEFAULT_BITMASKS[6]
| CFG6_EN_ANALOG // Enable Analog section
| CFG6_NEG_STOP_TEMP // Use internal Schmitt trigger
| CFG6_TW2_1 // 300µs to charge up the capacitor
| CFG6_TW2_0
| CFG6_FIREO_DEF // Low level by default of the inactive fire buffer
| CFG6_QUAD_RES // Enable quad resolution
| CFG6_ANZ_FIRE_END_0*1 // Fire 20 4+(16)
);
tdc.printConfigRegisters();
byte a = tdc.readRegister(READ_REG_1);
Serial.println(a,HEX);
Serial.println("Test communication: ");
Serial.print(tdc.testCommunication());
}
void loop() {
tdc.sendOpcode(OPCODE_INIT);
tdc.sendOpcode(OPCODE_START_TOF_RESTART);
tdc.waitForInterrupt(10000000);
delay(20);
Serial.println(tdc.readRegister(READ_RES_3),HEX);
}
The configurations of the registers are copied from the Application Note, from page 22 to page 25. I didn't use the temperature sensor so I jumped those steps related to that. No calibration neither. I just want to get some results of time of flight to be able to calculate the distance between two sensors for now. But the interrupt doesn't seem to work. What I got:
Go !
attached pinChangeISR_debug
Register 0: 0x430be800
Register 1: 0x21444000
Register 2: 0xa0138800
Register 3: 0xd0a24800
Register 4: 0x10004000
Register 5: 0x40000000
Register 6: 0xc0c06100
21
Test communication:
\/Test took 180 us
1
69978000
69978000
69978000
69978000
69978000
69978000
69978000
...
21 is the first byte of register 1, and 1 is the result of testcommunication(). These two means the test of communication is successful. But the results of reading RES_3 are always the same, and the waitForInterrupt() doesn't work(maybe the code shouldn't be written like this) -- Timeout all the time.
The two 1MHz ultrasonic sensors are put on the two sides of an iron panel (thickness 2.2mm), and I managed to get the signal with the help of oscilloscope (please see the attachments, the blue one is the signal of transmitter before amplification, green one is after amplification, yellow one is the signal of receiver), which seems to be correct. So I wonder how to read the measurement results correctly.
Here is the datasheet of TDC-GP22
This is my Ultrasonic Sensor
And my device of GP22 is the CJMCU-22
Any help appreciated,
Yinan
