Prevent current step-down going negative

Addressing #11348
2018-11-05 02:48:43 -06:00 · 2018-11-05 02:48:43 -06:00 · b779b42ffd
commit b779b42ffd
parent 427bc64ba1
1 changed files with 1 additions and 1 deletions
--- a/Marlin/src/feature/tmc_util.cpp
+++ b/Marlin/src/feature/tmc_util.cpp
@ -153,7 +153,7 @@
    #if CURRENT_STEP_DOWN > 0
      // Decrease current if is_otpw is true and driver is enabled and there's been more than 4 warnings
      if (data.is_otpw && st.isEnabled() && st.otpw_count > 4) {
-        st.rms_current(st.getMilliamps() - (CURRENT_STEP_DOWN));
+        st.rms_current(MAX(int16_t(st.getMilliamps() - (CURRENT_STEP_DOWN)), 0));
        #if ENABLED(REPORT_CURRENT_CHANGE)
          st.printLabel();
          SERIAL_ECHOLNPAIR(" current decreased to ", st.getMilliamps());