Add support for read PIO-A of DS2406 (#2174)

* Add support for read PIO-A of DS2406

* Verify reset() reseult

code/espurna/sensors/DallasSensor.h

@@ -16,6 +16,7 @@
 #include "BaseSensor.h"
 
 #define DS_CHIP_DS18S20             0x10
+#define DS_CHIP_DS2406              0x12
 #define DS_CHIP_DS1822              0x22
 #define DS_CHIP_DS18B20             0x28
 #define DS_CHIP_DS1825              0x3B
@@ -27,6 +28,40 @@
 #define DS_CMD_START_CONVERSION     0x44
 #define DS_CMD_READ_SCRATCHPAD      0xBE
 
+// ====== DS2406 specific constants =======
+
+#define DS2406_CHANNEL_ACCESS 0xF5;
+
+// CHANNEL CONTROL BYTE
+// 7    6    5    4    3    2    1    0 
+// ALR  IM   TOG  IC   CHS1 CHS0 CRC1 CRC0
+// 0    1    0    0    0    1    0    1        0x45
+
+// CHS1 CHS0 Description         
+// 0    0    (not allowed)                 
+// 0    1    channel A only 
+// 1    0    channel B only 
+// 1    1    both channels interleaved 
+
+// TOG  IM   CHANNELS       EFFECT
+// 0    0    one channel    Write all bits to the selected channel 
+// 0    1    one channel    Read all bits from the selected channel 
+// 1    0    one channel    Write 8 bits, read 8 bits, write, read, etc. to/from the selected channel 
+// 1    1    one channel    Read 8 bits, write 8 bits, read, write, etc. from/to the selected channel 
+// 0    0    two channels   Repeat: four times (write A, write B) 
+// 0    1    two channels   Repeat: four times (read A, read B) 
+// 1    0    two channels   Four times: (write A, write B), four times: (readA, read B), write, read, etc. 
+// 1    1    two channels   Four times: (read A, read B), four times: (write A, write B), read, write, etc.
+
+// CRC1 CRC0 Description
+// 0    0    CRC disabled (no CRC at all)
+// 0    1    CRC after every byte
+// 1    0    CRC after 8 bytes
+// 1    1    CRC after 32 bytes 
+#define DS2406_CHANNEL_CONTROL_BYTE 0x45;
+
+#define DS2406_STATE_BUF_LEN 7
+
 class DallasSensor : public BaseSensor {
 
     public:
@@ -120,37 +155,68 @@ class DallasSensor : public BaseSensor {
                 // Read scratchpads
                 for (unsigned char index=0; index<_devices.size(); index++) {
 
-                    // Read scratchpad
-                    if (_wire->reset() == 0) {
-                        // Force a CRC check error
-                        _devices[index].data[0] = _devices[index].data[0] + 1;
-                        return;
-                    }
+                    if (_devices[index].address[0] == DS_CHIP_DS2406) {
 
-                    _wire->select(_devices[index].address);
-                    _wire->write(DS_CMD_READ_SCRATCHPAD);
+                        uint8_t data[DS2406_STATE_BUF_LEN];
 
-                    uint8_t data[DS_DATA_SIZE];
-                    for (unsigned char i = 0; i < DS_DATA_SIZE; i++) {
-                        data[i] = _wire->read();
-                    }
+                        // Read scratchpad
+                        if (_wire->reset() == 0) {
+                            // Force a CRC check error
+                            _devices[index].data[0] = _devices[index].data[0] + 1;
+                            return;
+                        }
+                        
+                        _wire->select(_devices[index].address);
 
-                    if (_wire->reset() != 1) {
-                        // Force a CRC check error
-                        _devices[index].data[0] = _devices[index].data[0] + 1;
-                        return;
-                    }
+                        data[0] = DS2406_CHANNEL_ACCESS;
+                        data[1] = DS2406_CHANNEL_CONTROL_BYTE;
+                        data[2] = 0xFF;
 
-                    memcpy(_devices[index].data, data, DS_DATA_SIZE);
+                        _wire->write_bytes(data,3);
 
-                }
+                        // 3 cmd bytes, 1 channel info byte, 1 0x00, 2 CRC16
+                        for(int i = 3; i<DS2406_STATE_BUF_LEN; i++) {
+                            data[i] = _wire->read();
+                        }
 
-            }
+                        // Read scratchpad
+                        if (_wire->reset() == 0) {
+                            // Force a CRC check error
+                            _devices[index].data[0] = _devices[index].data[0] + 1;
+                            return;
+                        }
 
-            conversion = !conversion;
+                        memcpy(_devices[index].data, data, DS2406_STATE_BUF_LEN);
 
-        }
+                    } else {
+
+                        // Read scratchpad
+                        if (_wire->reset() == 0) {
+                            // Force a CRC check error
+                            _devices[index].data[0] = _devices[index].data[0] + 1;
+                            return;
+                        }
 
+                        _wire->select(_devices[index].address);
+                        _wire->write(DS_CMD_READ_SCRATCHPAD);
+
+                        uint8_t data[DS_DATA_SIZE];
+                        for (unsigned char i = 0; i < DS_DATA_SIZE; i++) {
+                            data[i] = _wire->read();
+                        }
+
+                        if (_wire->reset() != 1) {
+                            // Force a CRC check error
+                            _devices[index].data[0] = _devices[index].data[0] + 1;
+                            return;
+                        }
+
+                        memcpy(_devices[index].data, data, DS_DATA_SIZE);
+                    }
+                }
+            }
+            conversion = !conversion;
+        }
 
         // Descriptive name of the sensor
         String description() {
@@ -190,14 +256,20 @@ class DallasSensor : public BaseSensor {
 
         // Type for slot # index
         unsigned char type(unsigned char index) {
-            if (index < _count) return MAGNITUDE_TEMPERATURE;
+            if (index < _count) {
+                if (chip(index) == DS_CHIP_DS2406) {
+                    return MAGNITUDE_DIGITAL;
+                } else {
+                    return MAGNITUDE_TEMPERATURE;
+                }   
+            } 
             return MAGNITUDE_NONE;
         }
 
-	// Number of decimals for a magnitude (or -1 for default)
-	signed char decimals(unsigned char type) { 
-	  return 2; // smallest increment is 0.0625 C, so 2 decimals
-	}
+        // Number of decimals for a magnitude (or -1 for default)
+        signed char decimals(unsigned char type) { 
+        return 2; // smallest increment is 0.0625 C, so 2 decimals
+        }
 
         // Pre-read hook (usually to populate registers with up-to-date data)
         void pre() {
@@ -211,6 +283,26 @@ class DallasSensor : public BaseSensor {
 
             uint8_t * data = _devices[index].data;
 
+            if (chip(index) == DS_CHIP_DS2406) {
+
+                if (!OneWire::check_crc16(data, 5, &data[5])) {
+                    _error = SENSOR_ERROR_CRC;
+                    return 0;
+                }
+
+                // 3 cmd bytes, 1 channel info byte, 1 0x00, 2 CRC16
+                // CHANNEL INFO BYTE
+                // Bit 7 : Supply Indication 0 = no supply
+                // Bit 6 : Number of Channels 0 = channel A only
+                // Bit 5 : PIO-B Activity Latch
+                // Bit 4 : PIO-A Activity Latch
+                // Bit 3 : PIO B Sensed Level
+                // Bit 2 : PIO A Sensed Level
+                // Bit 1 : PIO-B Channel Flip-Flop Q
+                // Bit 0 : PIO-A Channel Flip-Flop Q
+                return (data[3] & 0x04) !=  0;
+            }
+
             if (OneWire::crc8(data, DS_DATA_SIZE-1) != data[DS_DATA_SIZE-1]) {
                 _error = SENSOR_ERROR_CRC;
                 return 0;
@@ -261,7 +353,7 @@ class DallasSensor : public BaseSensor {
         // ---------------------------------------------------------------------
 
         bool validateID(unsigned char id) {
-            return (id == DS_CHIP_DS18S20) || (id == DS_CHIP_DS18B20) || (id == DS_CHIP_DS1822) || (id == DS_CHIP_DS1825);
+            return (id == DS_CHIP_DS18S20) || (id == DS_CHIP_DS18B20) || (id == DS_CHIP_DS1822) || (id == DS_CHIP_DS1825) || (id == DS_CHIP_DS2406) ;
         }
 
         unsigned char chip(unsigned char index) {
@@ -275,6 +367,7 @@ class DallasSensor : public BaseSensor {
             if (chip_id == DS_CHIP_DS18B20) return String("DS18B20");
             if (chip_id == DS_CHIP_DS1822) return String("DS1822");
             if (chip_id == DS_CHIP_DS1825) return String("DS1825");
+            if (chip_id == DS_CHIP_DS2406) return String("DS2406");
             return String("Unknown");
         }