Revision 0:5965bf423184, committed 2019-09-13

Comitter:

epremeaux

Date:

Fri Sep 13 08:41:37 2019 +0000

Commit message:

initial commit. I dont trust the output values yet

Changed in this revision

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/F303_logger.h	Fri Sep 13 08:41:37 2019 +0000
@@ -0,0 +1,29 @@
+
+// Telemetry UART
+#define TELEM_TX    PA_9
+#define TELEM_RX    PA_10
+
+// Battery ADC
+#define BAT_V       PB_0
+
+// I2C
+#define I2CSDA      PB_7
+#define I2CSCL      PB_6
+
+// Strain Gauges
+#define LIFT_CLK    PB_1
+#define LIFT_DAT    PF_0
+#define DRAG_CLK    PF_1
+#define DRAG_DAT    PA_8
+
+// Buzzer
+
+// SD Card
+#define MOSI    PA_7
+#define MISO    PA_6
+#define SCLK    PA_5
+#define SSEL    PA_4 
+
+
+// Local ADC
+

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/MS4525DO/MS4525DO.cpp	Fri Sep 13 08:41:37 2019 +0000
@@ -0,0 +1,160 @@
+
+#include "mbed.h"
+#include "MS4525DO.h"
+
+
+MS4525DO::MS4525DO(PinName sda, PinName scl, char slave_adr)
+    :
+    i2c_p(new I2C(sda, scl)), 
+    i2c(*i2c_p),
+    address(slave_adr<<1)
+{
+    initialize();
+}
+
+MS4525DO::MS4525DO(I2C &i2c_obj, char slave_adr)
+    :
+    i2c_p(NULL), 
+    i2c(i2c_obj),
+    address(slave_adr<<1)
+{
+    initialize();
+}
+
+MS4525DO::~MS4525DO()
+{
+    if (NULL != i2c_p)
+        delete  i2c_p;
+}
+
+
+/* public functions
+        void initialize(void);
+        int measure(void);              // returns status of measurement
+        float getPSI(void);             // returns the PSI of last measurement
+        float getTemperature(void);     // returns temperature of last measurement
+        float getAirSpeed(void);        // calculates and returns the airspeed
+        int calibrate(void);            // attempts to calibrate and returns a status code
+        */
+
+void MS4525DO::initialize()
+{
+    // i2c writes to set up addresses, etc.
+    
+}
+
+// combine measure and collect into one function that returns the status code only, and holds the results in variables
+// other subroutines for returning clean values should be get functions
+
+
+int MS4525DO::measure()
+{
+    char ret;
+    ret = fetch_pressure(P_dat, T_dat);
+    return ret;
+}
+
+
+char MS4525DO::fetch_pressure(uint16_t &P_dat, uint16_t &T_dat)
+{
+    char _status;
+    char Press_H;
+    char Press_L;
+    char Temp_H;
+    char Temp_L;
+
+    char cmd[1];
+    cmd[0] = 0x00;
+    // So a device with a 'physical' address of 0x28, will need 'address bytes' of 0x50 for a write (R/W low), and 0x51 for a read (R/W high). 
+    //      MS4525DAddress
+    i2c.write(address, cmd, 1, true);  // select the register, no I2C Stop 
+       
+
+    char data[4];
+//    i2c.read(MS4525DAddress, static_cast<uint8_t>(4), static_cast<uint8_t>(true));  //Request 4 bytes, 2 pressure/status and 2 temperature
+    i2c.read(address, data, 4);
+    
+
+    Press_H = data[0];
+    Press_L = data[1];
+    Temp_H = data[2];
+    Temp_L = data[3];
+   
+     _status = (Press_H >> 6) & 0x03;
+    Press_H = Press_H & 0x3f;
+    P_dat = (((uint16_t)Press_H) << 8) | Press_L;
+
+    Temp_L = (Temp_L >> 5);
+    T_dat = (((uint16_t)Temp_H) << 3) | Temp_L;
+ 
+    return _status;
+}
+
+
+
+float MS4525DO::getPSI(void){             // returns the PSI of last measurement
+    // convert and store PSI
+    psi=(static_cast<float>(static_cast<int16_t>(P_dat)-MS4525ZeroCounts))/static_cast<float>(MS4525Span)*static_cast<float>(MS4525FullScaleRange);
+    // apply PSI calibration data
+    //   psi = psi + 0.007f;
+    
+    /* Below code is Pixhawk code which doesnt seem to work correctly */
+    // Calculate differential pressure. As its centered around 8000
+    // and can go positive or negative
+    /*
+    const float P_min = -1.0f;
+    const float P_max = 1.0f;
+    const float PSI_to_Pa = 6894.757f;
+    */ 
+    /*
+      this equation is an inversion of the equation in the
+      pressure transfer function figure on page 4 of the datasheet
+      We negate the result so that positive differential pressures
+      are generated when the bottom port is used as the static
+      port on the pitot and top port is used as the dynamic port
+     */
+     /*
+    float diff_press_PSI = -((T_dat - 0.1f * 16383) * (P_max - P_min) / (0.8f * 16383) + P_min);
+    float diff_press_pa_raw = diff_press_PSI * PSI_to_Pa;
+    */
+    
+    
+    return psi;
+}             
+  
+float MS4525DO::getTemperature(void){     // returns temperature of last measurement
+    // convert and store Temperature
+    temperature= (static_cast<float>(static_cast<int16_t>(T_dat)));
+    temperature = (temperature / 10);   // now in deg F
+    temperature = ((temperature -32) / 1.8f);   // now in deg C
+    
+    /* Below code is pixhawk version which DOES work correctly */
+    /*
+    PX4temperature = ((200.0f * T_dat) / 2047) - 50;
+    terminal.printf("PX4 Temperature: ");
+    terminal.printf("%0.1f\n", PX4temperature);
+    */
+    
+    return temperature;
+}
+
+float MS4525DO::getAirSpeed(void){        // calculates and returns the airspeed
+    /* Velocity calculation from a pitot tube explanation */
+    /* +/- 1PSI, approximately 100 m/s */
+    float rho = 1.225; // density of air 
+    // velocity = squareroot( (2*differential) / rho )
+    float velocity;
+    if (psi<0) {
+        velocity = -sqrt(-(2*psi) / rho);
+    }else{
+        velocity = sqrt((2*psi) / rho);
+        }
+    velocity = velocity*10;
+    
+    return velocity;
+}
+
+
+int MS4525DO::calibrate(void){            // attempts to calibrate and returns a status code
+
+}
\ No newline at end of file

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/MS4525DO/MS4525DO.h	Fri Sep 13 08:41:37 2019 +0000
@@ -0,0 +1,73 @@
+
+#ifndef MS4525DO_H
+#define MS4525DO_H
+
+#include "mbed.h"
+
+#define I2C_ADDRESS_MS4525DO    0x28    /**< 7-bit address =0x28. 8-bit is 0x50. Depends on the order code (this is for code "I") */
+
+/* Register address */
+#define ADDR_READ_MR            0x00    /* write to this address to start conversion */
+
+// MS4525D sensor full scale range and units
+const int16_t MS4525FullScaleRange = 1;  // 1 psi
+
+// MS4525D Sensor type (A or B) comment out the wrong type assignments
+// Type A (10% to 90%)
+const int16_t MS4525MinScaleCounts = 1638;
+const int16_t MS4525FullScaleCounts = 14746;
+
+const int16_t MS4525Span=MS4525FullScaleCounts-MS4525MinScaleCounts;
+
+//MS4525D sensor pressure style, differential or otherwise. Comment out the wrong one.
+//Differential
+const int16_t MS4525ZeroCounts=(MS4525MinScaleCounts+MS4525FullScaleCounts)/2;
+
+
+class MS4525DO
+{
+    public:
+    // instance methods
+        // explicit I2C pin names
+        MS4525DO(PinName sda, PinName sck, char slave_adr = I2C_ADDRESS_MS4525DO);
+        
+        // pin names as an object (ideal when sharing the bus)
+        MS4525DO(I2C &i2c_obj, char slave_adr = I2C_ADDRESS_MS4525DO);
+    
+        virtual ~MS4525DO();
+    
+    // public functions
+        void initialize(void);
+        int measure(void);              // returns status of measurement
+        float getPSI(void);             // returns the PSI of last measurement
+        float getTemperature(void);     // returns temperature of last measurement
+        float getAirSpeed(void);        // calculates and returns the airspeed
+        int calibrate(void);            // attempts to calibrate and returns a status code
+         
+    
+    private:
+        I2C         *i2c_p;
+        I2C         &i2c;
+        char        address;
+        char        _status;
+        float       psi;
+        float       temperature;
+        float       airspeed;
+        uint16_t    P_dat;  // 14 bit pressure data
+        uint16_t    T_dat;  // 11 bit temperature data
+        
+    // private functions
+        int collect(void);
+        char fetch_pressure(uint16_t &P_dat, uint16_t &T_dat);
+          
+    
+};  // end of the class
+
+
+/** airspeed scaling factors; out = (in * Vscale) + offset */
+struct airspeed_scale {
+    float   offset_pa;
+    float   scale;
+};
+
+#endif 

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Fri Sep 13 08:41:37 2019 +0000
@@ -0,0 +1,46 @@
+#include "mbed.h"
+#include "F303_logger.h"
+#include "MS4525DO.h"
+
+Serial terminal(USBTX, USBRX);
+I2C i2c(I2CSDA, I2CSCL);
+
+MS4525DO Pitot(i2c); 
+
+DigitalOut myled(LED1);
+
+
+int main() {
+    terminal.baud(115200); 
+    terminal.printf("MS4525DO library test\n");
+
+    while(1) {
+        char PitotStatus;    // A two bit field indicating the status of the I2C read
+        PitotStatus = Pitot.measure();
+
+        switch (PitotStatus)
+        {
+            case 0:
+            //Serial.println("Ok ");
+            terminal.printf("PSI: %f\n", Pitot.getPSI());
+            terminal.printf("Temperature: %f\n", Pitot.getTemperature());
+            terminal.printf("Airspeed: %f\n", Pitot.getAirSpeed());
+            terminal.printf("\n");
+            break;
+            
+            case 1:
+            terminal.printf("Busy\n");
+            break;
+            
+            case 2:
+            terminal.printf("Stale\n");
+            break;
+            
+            default:
+            terminal.printf("Error\n");
+            break;
+        }
+        myled = !myled;
+        wait_ms(200);
+    }
+}

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mbed.bld	Fri Sep 13 08:41:37 2019 +0000
@@ -0,0 +1,1 @@
+https://os.mbed.com/users/mbed_official/code/mbed/builds/65be27845400
\ No newline at end of file