Merge pull request #8616 from aik/development-v2

Add MAX6675 sensor (v2)
arendst · Jun 4, 2020 · 676a13f · 676a13f
2 parents a799ba3 + 5558da5
commit 676a13f
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Showing 2 changed files with 15 additions and 1 deletion.
diff --git a/tasmota/settings.h b/tasmota/settings.h
@@ -113,7 +113,7 @@ typedef union {                            // Restricted by MISRA-C Rule 18.4 bu
     uint32_t fade_at_startup : 1;          // bit 9 (v8.2.0.3)   - SetOption91 - Enable light fading at start/power on
     uint32_t pwm_ct_mode : 1;              // bit 10 (v8.2.0.4)  - SetOption92 - Set PWM Mode from regular PWM to ColorTemp control (Xiaomi Philips ...)
     uint32_t compress_rules_cpu : 1;       // bit 11 (v8.2.0.6)  - SetOption93 - Keep uncompressed rules in memory to avoid CPU load of uncompressing at each tick
-    uint32_t spare12 : 1;
+    uint32_t max6675 : 1;                  // bit 12 (v8.3.1.2)  - SetOption94 - Implement simpler MAX6675 protocol instead of MAX31855
     uint32_t spare13 : 1;
     uint32_t spare14 : 1;
     uint32_t spare15 : 1;

diff --git a/tasmota/xsns_39_max31855.ino b/tasmota/xsns_39_max31855.ino
@@ -50,6 +50,20 @@ void MAX31855_Init(void){
 *   Acquires the raw data via SPI, checks for MAX31855 errors and fills result structure
 */
 void MAX31855_GetResult(void){
+    // Controlled via SetOption94
+    if (Settings.flag4.max6675) {
+        int32_t RawData = MAX31855_ShiftIn(16);
+        int32_t temp = (RawData >> 3) & ((1 << 12) - 1);
+
+        /* Occasionally the sensor returns 0xfff, consider it an error */
+        if (temp == ((1 << 12) - 1))
+            return;
+
+        MAX31855_Result.ErrorCode = 0;
+        MAX31855_Result.ReferenceTemperature = NAN;
+        MAX31855_Result.ProbeTemperature = ConvertTemp(0.25 * temp);
+        return;
+    }
     int32_t RawData = MAX31855_ShiftIn(32);
     uint8_t probeerror = RawData & 0x7;