Joseph Ellsworth / Mbed 2 deprecated xj-Nucleo-F303K8-SHT75-TEST

Testing SHT75 humidity sensor on STM F303K8 board.

Dependencies:   SHT75 mbed

Fork of Nucleo-F303K8-SSD1306_OLED by Joseph Ellsworth

Sample code to test SHT75 humidity sensor using STM F303K8 board. Uses a 3.3V from board to power sensor. 10K resistor Pull-up on data. Must not be on same pins as I2C. Uses D0 for Clk and D1 for Data.

I had to modify sample code supplied by https://developer.mbed.org/users/nimbusgb/code/SHT75/ because the sensor failed to read without the softReset() and readStatus() at beginning of measurement loop. I think this is caused by the 72Mhtz speed of the F303K8 but did not attempt to fully diagnose.

The readStatus() method from library seems to malfunction and always return a -1 which never changes even when sensor is unplugged.

See https://www.sensirion.com/fileadmin/user_upload/customers/sensirion/Dokumente/Humidity_Sensors/Sensirion_Humidity_Sensors_SHT7x_Datasheet_V5.pdf section 2.1 for wiring.

Diff: main.cpp

Revision:
1:90d213185462
Parent:
0:fa185766e039
Child:
2:dc3e84d595c3
--- a/main.cpp	Sat Mar 19 02:18:42 2016 +0000
+++ b/main.cpp	Mon Mar 21 00:11:05 2016 +0000
@@ -1,23 +1,46 @@
-/* Example of Reading all the ADC pins available on the Nucleo_F303K8. 
- by Joseph Ellsworth CTO A2WH -  Free for all but no warranty, no promises */
+/* Example of Reading all the ADC pins PIN and display ot OLED display using
+ Nucleo_F303K8 by Joseph Ellsworth CTO A2WH -  Free for all but no warranty, no promises 
+ Attempt to drive:  
+   ebay part http://www.ebay.com/itm/152000005331?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT
+  0-96-I2C-IIC-SPI-Serial-White-OLED-LCD-LED-Display-Module-128X64
+  The Datasheet.  https://www.adafruit.com/datasheets/SSD1306.pdf
+  
+  Unfortunately this part never turns on using the SSD1308 library.
+  Not sure why and don't have time to finish tracking it down at this 
+  time. 
+  
+  Using my I2C address scanner I found that it responds on Added 120 (x78) ,121 (x79)
+  and when the part was unsoldered nothing responded on 120 or 121. According to 
+  to the page #19 (8.1.5) of the data sheet the I2C address should be 011110
+  which seems to map correctly to dec=120 hex=79 so I think the chip is responsive
+  and the library must be sending incorrect commands.
+  
+ */
 
 #include "mbed.h"
+#include "SSD1308.h"
 
-// Initialize a pins to perform analog input and digital output fucntions
-AnalogIn   aA7(PA_2);
-AnalogIn   aA6(PA_7);
-AnalogIn   aA5(PA_6);
-AnalogIn   aA4(PA_5);
-AnalogIn   aA3(PA_4);
-AnalogIn   aA2(PA_3);
-AnalogIn   aA1(PA_1); 
-AnalogIn   aA0(PA_0); 
-AnalogIn   aB0(PB_0); 
-AnalogIn   aB1(PB_1); 
+//#include "mbed_logo.h"
+ 
+ //Pin Defines for I2C Bus
+ #define D_SDA                  PB_7 // specific for Nucleo-F303K8
+ #define D_SCL                  PB_6 // specific for Nucleo-F303K8
+ I2C i2c(D_SDA, D_SCL);
+ 
+ // Host PC Communication channels
+ Serial pc(USBTX, USBRX); // tx, rx
+ 
+ // Instantiate OLED
+ //SSD1308 oled = SSD1308(i2c, SSD1308_SA0);
+ SSD1308 oled = SSD1308(i2c, SSD1308_SA1);
+ //SSD1308 oled = SSD1308(i2c, 120);
+ 
+AnalogIn   pa0(PA_0); 
  
 DigitalOut myled(LED1);
 const float voltMeterARef = 3.3;
 
+char buff[100];
 float readPrint(AnalogIn ain, char *label) {
   float tval = ain.read();
   float volts = tval * voltMeterARef;
@@ -25,28 +48,33 @@
   unsigned short  tvalu16 = ain.read_u16 ();
 
   printf("adc %s R=%3.3f V=%3.3f%% U16=%u\r\n",label, tval, volts, tvalu16);
-  
+  sprintf(buff, "V=%3.3f%",volts);
+  oled.printf(buff);
   return tval;
 }
     
 
 int main() {
+    pc.printf("OLED test start\r");  
+    oled.writeString(0, 0, "Hello World !");
+    oled.printf("Hello World !");
+  
+    oled.fillDisplay(0xAA);
+    oled.setDisplayOff();
+    wait(1);   
+    oled.setDisplayOn();
+    oled.clearDisplay();
+    oled.setDisplayInverse();
+    wait(0.5);
+    oled.setDisplayNormal();                                         
+    //oled.writeBitmap((uint8_t*) mbed_logo);
+    pc.printf("OLED test done\r\n");  
+  
+
 
     while(1) {
         myled = !myled; // toggle led 
-        readPrint(aA7, "PA_7");
-        readPrint(aA6, "PA_6");
-        readPrint(aA5, "PA_5");
-        readPrint(aA4, "PA_4");
-        readPrint(aA3, "PA_3");
-        readPrint(aA2, "PA_2");
-        readPrint(aA1, "PA_1");
-        readPrint(aA0, "PA_0");
-        
-        readPrint(aB0, "PB_0");
-        readPrint(aB1, "PB_1");
-        printf("\r\n\r\n");
-        wait(7.0);
-        
+        readPrint(pa0, "PA_0");                
+        wait(7.0);        
     }
 }