Diff: LTC2487/LTC2487.cpp

Revision:

0:a28a1035c31b

Child:

1:0182b86f9bd4

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/LTC2487/LTC2487.cpp	Mon Jan 22 20:11:52 2018 +0000
@@ -0,0 +1,68 @@
+#include "mbed.h"
+#include "LTC2487.h"
+#include "MODSERIAL.h"
+
+namespace {
+    const uint8_t I2C_WRITE  = 0x00;
+    const uint8_t I2C_READ   = 0x01;
+    
+    //Channel addresses
+    //0b10110000 ch0 --> 0xb0
+    //0b10111000 ch1 --> 0xb8
+    //0b10110001 ch2 --> 0xb1
+    //0b10111001 ch3 --> 0xb9
+    const uint8_t CHNL_0     = 0xb0;
+    const uint8_t CHNL_1     = 0xb8;
+    const uint8_t CHNL_2     = 0xb1;
+    const uint8_t CHNL_3     = 0xb9;
+};
+
+LTC2487::LTC2487 (PinName sda, PinName scl, uint8_t address, int freq): i2c( sda, scl ){
+    addrI2C = address;
+    i2c.frequency(freq);
+}
+
+void LTC2487::setAddress(int address){
+    addrI2C = address;
+}
+
+float LTC2487::readOutput(int chnl){
+    char ADC_channel[1];
+    char ADC_data_rx[3];
+    char ADC_config[1];
+    ADC_config[0] = 0x82;
+        
+    //select channel to read
+    switch (chnl){
+        case 0:
+            ADC_channel[0] = CHNL_0;
+            break;
+        case 1:
+            ADC_channel[0] = CHNL_1;
+            break;
+        case 2:
+            ADC_channel[0] = CHNL_2;
+            break;
+        case 3:
+            ADC_channel[0] = CHNL_3;
+            break;
+    } 
+    
+    //send message to select channel
+    i2c.write((addrI2C<<1)|(I2C_WRITE), ADC_channel, 1);
+    //must wait, otherwise breaks...
+    wait(0.3);
+    //send configuration (1 gain, autocalibration
+    i2c.write((addrI2C<<1)|(I2C_WRITE), ADC_config, 1);
+    //must wait, otherwise breaks...
+    wait(0.3);
+    //Read data from selected channel --> 24bits --> 23bit=SIGN 22bit=MSB 21-7bits=DATA 5-0bits=JUNK
+    i2c.read((addrI2C<<1)|(I2C_READ), ADC_data_rx, 3); 
+    //Stich togethor the bytes into a 24bit value
+    unsigned long data = (ADC_data_rx[0] << 16) | (ADC_data_rx[1] << 8)| ADC_data_rx[2];
+    //Delete SIGN bit and MSB bit and remove 6 JUNK bits
+    unsigned long ADC_Result = (data&0x3fffff)>>6;    
+    
+    return float(float(ADC_Result));
+
+}