From e31bef31ad4ce8f97b892ccccec4947c8fc372d4 Mon Sep 17 00:00:00 2001
From: Erik van der Zalm <erik@vdzalm.eu>
Date: Wed, 16 May 2012 19:32:23 +0200
Subject: [PATCH] Limit PID autotune PWM to PID_MAX
---
Marlin/temperature.cpp | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/Marlin/temperature.cpp b/Marlin/temperature.cpp
index e21bd2598da..395061cc212 100644
--- a/Marlin/temperature.cpp
+++ b/Marlin/temperature.cpp
@@ -134,8 +134,8 @@ void PID_autotune(float temp)
long t_high;
long t_low;
- long bias=127;
- long d = 127;
+ long bias=PID_MAX/2;
+ long d = PID_MAX/2;
float Ku, Tu;
float Kp, Ki, Kd;
float max, min;
@@ -144,7 +144,7 @@ void PID_autotune(float temp)
disable_heater(); // switch off all heaters.
- soft_pwm[0] = 255>>1;
+ soft_pwm[0] = PID_MAX/2;
for(;;) {
@@ -172,8 +172,8 @@ void PID_autotune(float temp)
t_low=t2 - t1;
if(cycles > 0) {
bias += (d*(t_high - t_low))/(t_low + t_high);
- bias = constrain(bias, 20 ,235);
- if(bias > 127) d = 254 - bias;
+ bias = constrain(bias, 20 ,PID_MAX-20);
+ if(bias > PID_MAX/2) d = PID_MAX - 1 - bias;
else d = bias;
SERIAL_PROTOCOLPGM(" bias: "); SERIAL_PROTOCOL(bias);