From 54572ac7f25abfc772a7ff3d770314f0962b8db0 Mon Sep 17 00:00:00 2001
From: Eggert Jung <eggert.s.jung@wischhof13.de>
Date: Sat, 2 Apr 2022 16:23:48 +0200
Subject: [PATCH] introduce (crude) false-reading detection

---
 kraftsensor.c | 25 ++++++++++++++++++++++++-
 1 file changed, 24 insertions(+), 1 deletion(-)

diff --git a/kraftsensor.c b/kraftsensor.c
index 066d428..7823db3 100644
--- a/kraftsensor.c
+++ b/kraftsensor.c
@@ -1,4 +1,6 @@
 #include <avr/io.h>
+#include <stdint.h>
+#include <stdlib.h>
 #include <util/delay.h>
 #include <stdio.h>
 #include <avr/interrupt.h>
@@ -25,7 +27,10 @@ void kraftsensor_init(){
 }
 
 void do_kraftsensor(){
+    static int32_t last_read;
+    static int32_t old_value;
     uint16_t m_data[4];
+    int32_t kraftsensor_read;
 
     /* read 2 16bit values and merge to 32bit signed integer */
     readReg(1,0,2);
@@ -38,8 +43,26 @@ void do_kraftsensor(){
         int32_t tmp = (uint32_t)m_data[1]<<16;
         tmp |= m_data[0];
 
+        //kraftsensor_value = tmp;
         /* conversion magic to milliNewton */
-        kraftsensor_value = ((tmp + 539363)*9.81)/177.380;
+        kraftsensor_read = ((tmp + 197700 /*539363*/)*9.81)/177.380;
+
+        if(abs(kraftsensor_read - old_value) > 10000){
+            if(abs(last_read - kraftsensor_read) > 10000){
+                kraftsensor_value = old_value;
+                printf("delta: %d\tvalue:%ld\n", kraftsensor_read - old_value, kraftsensor_read);
+                printf("spike\n");
+            }
+            else{
+                kraftsensor_value = kraftsensor_read;
+                printf("jump\n");
+            }
+        }
+        else{
+            kraftsensor_value = kraftsensor_read;
+        }
+        last_read = kraftsensor_read;
+        old_value = kraftsensor_value;
     }
 
 }