Diff: main.cpp

Revision:

0:cf0be1174e43

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Mon Mar 23 05:57:30 2020 +0000
@@ -0,0 +1,152 @@
+#include "mbed.h"
+#include "Adafruit_ADS1015.h"
+#include "SDFileSystem.h"
+#define ADS1115_ADDR 0b1001000
+
+Serial pc(USBTX, USBRX, 115200);
+I2C i2c(p28, p27);
+Adafruit_ADS1115 ads1115(&i2c, ADS1115_ADDR);
+SDFileSystem sd_file_system(p5, p6, p7, p8, "sd");
+Timer sd_timer;
+
+FILE *sd;
+char file_name[64];
+char f_sd;
+int16_t val[4] = {};
+float voltage[4] = {};
+float sum[4] = {};
+float v_ave[4] = {};
+float strain_v[4] = {};
+
+int main()
+{
+    ads1115.setGain(GAIN_TWOTHIRDS);
+
+    char file_name_format[] = "/sd/IZU2020_MISSION_%d.dat";
+    int file_number = 1;
+    while(1) {
+        sprintf(file_name, file_name_format, file_number);
+        sd = fopen(file_name, "r");
+        if(sd != NULL) {
+            fclose(sd);
+            file_number++;
+        } else {
+            sprintf(file_name, "/sd/IZU2020_MISSION_%d.dat", file_number);
+            break;
+        }
+    }
+    sd = fopen(file_name, "w");
+    sd_timer.start();
+    if(sd) {
+        fprintf(sd, "f_sd, ");
+        fprintf(sd, "speed[m/s],");
+        fprintf(sd, "sigma1,");
+        fprintf(sd, "sigma2,");
+        fprintf(sd, "taumax[MPa],");
+        fprintf(sd, "\r\n");
+    }
+
+    for(int i = 0; i < 10; i ++ ) {
+        val[0] = ads1115.readADC_SingleEnded(0);
+        val[1] = ads1115.readADC_SingleEnded(1);
+        val[2] = ads1115.readADC_SingleEnded(2);
+        val[3] = ads1115.readADC_SingleEnded(3);
+        voltage[0] = val[0] / 32768.0 * 6.144;
+        voltage[1] = val[1] / 32768.0 * 6.144;
+        voltage[2] = val[2] / 32768.0 * 6.144;
+        voltage[3] = val[3] / 32768.0 * 6.144;
+        sum[0] += voltage[0];
+        sum[1] += voltage[1];
+        sum[2] += voltage[2];
+        sum[3] += voltage[3];
+    }
+    v_ave[0] = sum[0] / 10.0;
+    v_ave[1] = sum[1] / 10.0;
+    v_ave[2] = sum[2] / 10.0;
+    v_ave[3] = sum[3] / 10.0;
+
+    while(1) {
+        val[0] = ads1115.readADC_SingleEnded(0);
+        val[1] = ads1115.readADC_SingleEnded(1);
+        val[2] = ads1115.readADC_SingleEnded(2);
+        val[3] = ads1115.readADC_SingleEnded(3);
+        voltage[0] = val[0] / 32768.0 * 6.144;
+        voltage[1] = val[1] / 32768.0 * 6.144;
+        voltage[2] = val[2] / 32768.0 * 6.144;
+        voltage[3] = val[3] / 32768.0 * 6.144;
+        pc.printf("%d, r%d, g%d, w%d\r\n",  val[0], val[1], val[2], val[3]);
+        pc.printf("%f, r%f, g%f, w%f [V]\r\n",  voltage[0], voltage[1], voltage[2], voltage[3]);
+
+        /*pitot_tube
+        -------------------------------------------------*/
+        float pitot_v = voltage[0] - v_ave[0] + 1;
+        //P = ((Vout / Vs) - 0.2) / 0.2
+        float pitot_Pa = (pitot_v / 5.0 - 0.2) / 0.2;
+        printf("pressure %f[kPa]\r\n", pitot_Pa);
+        float density = 1.3;
+        //v = root(2 * P / ρ)
+        float pitot_speed = sqrt(2 * pitot_Pa * 1000 / density);
+        printf("speed %f[m/s]\r\n", pitot_speed);
+        printf("speed %f[km/h]\r\n", pitot_speed * 3600 / 1000.0);
+        
+        /*strain_gauge
+        ----------------------------------------------------*/
+        strain_v[1] = voltage[1] - v_ave[1];
+        strain_v[2] = voltage[2] - v_ave[2];
+        strain_v[3] = voltage[3] - v_ave[3];
+        //VOUT – VREF = G(VIN+ – VIN–)
+        //VREF = GND
+        //G = (49.4kΩ/RG) + 1
+        //straun = 2/3.3*V
+        float G = (49.4 * 1000 / 120.0) + 1;
+        float V1 = strain_v[1] / G;
+        float strain1 = 2 / 3.3 * V1 * 1000000.0;
+        float V2 = strain_v[2] / G;
+        float strain2 = 2 / 3.3 * V2 * 1000000.0;
+        float V3 = strain_v[3] / G;
+        float strain3 = 2 / 3.3 * V3 * 1000000.0;
+        printf("strain r %f g %f w %f [uε]\r\n", strain1, strain2, strain3);
+
+        float E = 2.5;//Al 72GPa
+        float nu = 0.3;//ポアソン比
+        float g = E / 2 / (1 + nu); //横弾性係数
+        float sigmax = E / (1 - nu * nu) * (strain1 + nu * strain3) / 1000.0;
+        float sigmay = E / (1 - nu * nu) * (nu * strain1 + strain3) / 1000.0;
+        float gammaxy = 2 * strain2 - strain1 - strain3;
+        float tauxy = g * gammaxy / 1000.0;
+        float sigma1 = (sigmax + sigmay) + sqrt((sigmax - sigmay) * (sigmax - sigmay) + 4 * tauxy * tauxy);
+        float sigma2 = (sigmax + sigmay) - sqrt((sigmax - sigmay) * (sigmax - sigmay) + 4 * tauxy * tauxy);
+        float taumax = (sigma1 - sigma2) / 2.0;
+        printf("sigmax %f sigmay %f tauxy %f [MPa]\r\n", sigmax, sigmay, tauxy);
+        printf("sigma1 %f sigma2 %f taumax %f [MPa]\r\n", sigma1, sigma2, taumax);
+        
+        /*sd
+        --------------------------------------------------------*/
+        f_sd = bool(sd);
+        if(sd) {
+            fprintf(sd, "%d,", f_sd);
+            fprintf(sd, "%f,", pitot_speed);
+            fprintf(sd, "%f,", sigma1);
+            fprintf(sd, "%f,", sigma2);
+            fprintf(sd, "%f,", taumax);
+            fprintf(sd, "\r\n");
+        }
+        if(sd_timer.read_ms() >= 60*1000) {
+            sd_timer.reset();
+            sd_timer.start();
+            if(sd) {
+                fclose(sd);
+                sd = fopen(file_name, "a");
+            }
+        }
+        
+        /*test
+        ----------------------------------------------------*/
+        float P = 5.0 * 9.8;
+        float A = 14.5 * 3.0;
+        float sigma = P / A;
+        pc.printf("test %f\r\n", sigma);
+        
+        wait(0.5);
+    }
+}