From 017ac159def18f9d9ec8ae7745f8cad7c9d14014 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?S=C3=B8ren=20Rasmussen?= <sr@jondahl.net>
Date: Tue, 26 Jul 2022 21:28:13 +0200
Subject: [PATCH] Check DS18B20 bulk read status before reading

---
 pkg/temperature/ds18b20.go | 54 ++++++++++++++++++++------------------
 1 file changed, 28 insertions(+), 26 deletions(-)

diff --git a/pkg/temperature/ds18b20.go b/pkg/temperature/ds18b20.go
index 1dc1903..8b8aa48 100644
--- a/pkg/temperature/ds18b20.go
+++ b/pkg/temperature/ds18b20.go
@@ -78,37 +78,13 @@ func PollSensors(ctx context.Context, wg *sync.WaitGroup, readingInterval time.D
 	work_loop:
 		select {
 		case <-ticker.C:
-			start := time.Now()
-
-			if accErrTrigger > 60 {
-				log.Fatal("Thermal bulk read failed 60 times in a row -- terminating")
-			}
-
-			// Trigger a bulk read to start conversion on all sensors.
-			if err := triggerBulkRead(); err != nil {
-				accErrTrigger++
-				hub.CaptureException(err)
-				log.Print(err)
-				break
-			}
-
-			accErrTrigger = 0
-
-			// Ensure that we wait for sensors to convert data.
-			deltaSleep := sensorConversionTime - time.Since(start)
-			if deltaSleep > 0 {
-				// Wait for sensors to convert data.
-				time.Sleep(deltaSleep)
-			}
-
-			// Poll bus state
 		poll_bus:
 			state, err := pollBusState()
 			if err != nil {
 				accErrTrigger++
 				hub.CaptureException(err)
 				log.Print(err)
-				break work_loop
+				break
 			}
 
 			switch state {
@@ -116,10 +92,36 @@ func PollSensors(ctx context.Context, wg *sync.WaitGroup, readingInterval time.D
 				time.Sleep(busPollDelay)
 				goto poll_bus
 
-			case BulkReadIdle, BulkReadReady:
+			case BulkReadIdle:
+				start := time.Now()
+
+				// Trigger a bulk read to start conversion on all sensors.
+				if err := triggerBulkRead(); err != nil {
+					accErrTrigger++
+					hub.CaptureException(err)
+					log.Print(err)
+					break work_loop
+				}
+
+				accErrTrigger = 0
+
+				// Ensure that we wait for sensors to convert data.
+				deltaSleep := sensorConversionTime - time.Since(start)
+				if deltaSleep > 0 {
+					// Wait for sensors to convert data.
+					time.Sleep(deltaSleep)
+				}
+
+				goto poll_bus
+
+			case BulkReadReady:
 				readSensors(hub)
 			}
 
+			if accErrTrigger > 60 {
+				log.Fatal("Thermal bulk read failed 60 times in a row -- terminating")
+			}
+
 		case c := <-ConfigUpdate:
 			configure(c)