Diff: PeripheralLayer/PeMod_ZPH01.cpp

Revision:

0:3dac4f477e98

Child:

1:0c1053275589

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/PeripheralLayer/PeMod_ZPH01.cpp	Wed Jul 08 17:50:18 2015 +0000
@@ -0,0 +1,83 @@
+#include "SysConfig.h"
+
+#define ZPH01_CMD_LEN   0
+#define ZPH01_DAT_LEN   9
+#define ZPH01_GAS_ID    0x18
+
+#define uart_zph01 uart_sen
+#define uart_db uart_pc
+
+int ZPH01_Init(void)
+{    
+    return 0;    
+}
+
+float ZPH01_ReadPM25(void)
+{
+    int tmp, sum, i;
+    uint8_t data[ZPH01_DAT_LEN];
+                   
+    #if defined uart_db
+    uart_db.printf("\n\rZPH01 return ");
+    #endif
+    
+    do{
+        while(!uart_zph01.readable());
+        
+        tmp = uart_zph01.getc();
+        #if defined uart_db
+        uart_db.printf("0x%02X ", tmp);
+        #endif
+    }while(tmp != 0xFF);
+    data[0] = 0xFF;
+    
+    do{
+        while(!uart_zph01.readable());
+        tmp = uart_zph01.getc();
+        #if defined uart_db
+        uart_db.printf("0x%02X ", tmp);
+        #endif
+    }while(tmp != ZPH01_GAS_ID);
+    data[1] = ZPH01_GAS_ID;
+               
+    for(i=2; i<ZPH01_DAT_LEN; i++)
+    {        
+        data[i] = uart_zph01.getc();
+        #if defined uart_db
+        uart_db.printf("0x%02X ", data[i]);
+        #endif
+    }    
+    
+    #if defined uart_db
+    uart_db.printf(".\n\r");
+    #endif
+    
+    sum = ZPH01_CalCheckSum(data);
+    if(data[ZPH01_DAT_LEN - 1] == sum)
+    {
+        //Unit: percents(%)
+        float ratioPM25 = data[3] * 1.0 + data[3] / 255.0;
+        //Unit: ug/m^3
+        float volPM25 = ratioPM25 * 20.43;
+        return volPM25;
+    }
+    else
+    {
+        #if defined uart_db
+        uart_db.printf("Incorrect checksum 0x%02X, expect 0x%02X.\n\r", sum, data[ZPH01_DAT_LEN - 1]);
+        #endif
+        return -1;
+    }
+}
+
+uint8_t ZPH01_CalCheckSum(uint8_t *packet)
+{
+    uint8_t i, checksum = 0;
+    for( i = 1; i < 8; i++)
+    {
+        checksum += packet[i];
+    }
+    checksum = 0xff - checksum;
+    checksum += 1;
+    return checksum;
+}