Diff: mcp342x.cpp

Revision:

4:9480edf3926d

Parent:

3:03911aa07029

Child:

5:0ca445d2d2bc

--- a/mcp342x.cpp	Tue Jul 18 09:43:27 2017 +0000
+++ b/mcp342x.cpp	Mon Sep 10 17:02:22 2018 +0000
@@ -1,6 +1,7 @@
 #include "mcp342x.h"
 
 #define LEN_ONE_BYTE 1
+extern Serial pc;
 
 MCP342x::MCP342x(I2C *i2c, uint8_t device_address)
 {
@@ -14,7 +15,7 @@
     // Initialise to default settings: channel 1, gain 1x, 12 bits.
     // It is necessary to do this to ensure that the variables
     // _resolution and _pga are properly set.
-    _configuration = 0x10;
+    _configuration = 0x10;      // Continuous mode
     set_channel(CHANNEL_1);
     set_resolution(RESOLUTION_12);
     set_pga(PGA_1);
@@ -50,7 +51,7 @@
     //
     // _max_code is the maximum output code, and it is equal to
     // 2^(N-1) - 1 (datasheet Table 4-3).
-    switch(_resolution){
+    switch(_resolution) {
         case RESOLUTION_12:
             _lsb = 2 * 2.048 / 4096;
             _max_code = 2047;
@@ -103,14 +104,47 @@
 
 void MCP342x::_write_configuration()
 {
+//    pc.printf("MCP3424 config %0X\r\n", _configuration );
     _i2c_command[0] = _configuration;
     _i2c->write(_address, _i2c_command, LEN_ONE_BYTE);
 }
 
+uint8_t MCP342x::read_configuration()
+{
+//    pc.printf("MCP3424 config %0X\r\n", _configuration );
+    _i2c_command[0] = _configuration;
+    _i2c->read(_address, _i2c_command, LEN_ONE_BYTE);
+    return _i2c_command[0];
+}
+
+void MCP342x::_startRead()
+{
+    _i2c_command[0] = _configuration | 0x80;
+    _i2c->write(_address, _i2c_command, LEN_ONE_BYTE);
+}
+
 uint32_t MCP342x::read()
 {
     uint32_t adc_value = 0;
-    _i2c->read(_address, _i2c_command, COMMAND_N_BYTES);
+    uint8_t readConfig = 0;
+    int byteNum = 3;
+    
+    if( (_configuration & 0x10) == 0 )
+        _startRead();
+
+    // Read config register
+    if (_resolution == RESOLUTION_18 ) {
+        byteNum = 4;
+    }
+
+    _i2c->read(_address, _i2c_command, byteNum);
+
+    while( (_i2c_command[byteNum-1] & 0x80) == 0x80 ) {
+       wait_ms(10);
+       // pc.printf("MCP3424 config %0X %0X %0X %0X\r\n", _i2c_command[0],_i2c_command[1],_i2c_command[2],_i2c_command[3] );
+        _i2c->read(_address, _i2c_command, byteNum);
+    }
+
 
     switch (_resolution) {
         case RESOLUTION_12:
@@ -130,14 +164,15 @@
 
         case RESOLUTION_18:
             adc_value = (_i2c_command[0] << 16) |
-                (_i2c_command[1] << 8) | _i2c_command[2];
+                        (_i2c_command[1] << 8) | _i2c_command[2];
             adc_value &= 0x3ffff;
             break;
     }
     return adc_value;
 }
 
-float MCP342x::read_volts(){
+float MCP342x::read_volts()
+{
     float volts = 0.0;
     uint32_t adc_value = read();