tmc2240: adjustable current scaler and current range

README.md

@@ -128,6 +128,8 @@ See the [Danger Features document](https://docs.kalico.gg/Danger_Features.html)
 
 - [danger_options: configurable homing constants](https://github.com/KalicoCrew/kalico/pull/378)
 
+- [tmc2240: adjustable driver_CS and current_range](https://github.com/KalicoCrew/kalico/pull/556)
+
 If you're feeling adventurous, take a peek at the extra features in the bleeding-edge-v2 branch [feature documentation](docs/Bleeding_Edge.md)
 and [feature configuration reference](docs/Config_Reference_Bleeding_Edge.md):
 

docs/Config_Reference.md

@@ -2634,11 +2634,11 @@ for more detailed information regarding symptoms, configuration and setup.
 calibrate_start_x: 20
 #   Defines the minimum X coordinate of the calibration
 #   This should be the X coordinate that positions the nozzle at the starting
-#   calibration position. 
+#   calibration position.
 calibrate_end_x: 200
 #   Defines the maximum X coordinate of the calibration
 #   This should be the X coordinate that positions the nozzle at the ending
-#   calibration position. 
+#   calibration position.
 calibrate_y: 112.5
 #   Defines the Y coordinate of the calibration
 #   This should be the Y coordinate that positions the nozzle during the
@@ -4427,6 +4427,13 @@ run_current:
 #   velocity" threshold (THIGH) to. This is typically used to disable
 #   the "CoolStep" feature at high speeds. The default is to not set a
 #   TMC "high velocity" threshold.
+#current_range:
+#   The current_range bit value for the driver. Valid values are 0 and 32-255.
+#   The defaul is to auto-calculate to match the requested run_current.
+#   For further information consult the tmc2240 datasheet and tuning table.
+#driver_CS: 31
+#   The current_scaler value for the driver. The default is 31.
+#   For further information consult the tmc2240 datasheet and tuning table.
 #driver_MSLUT0: 2863314260
 #driver_MSLUT1: 1251300522
 #driver_MSLUT2: 608774441

docs/Kalico_Additions.md

@@ -55,6 +55,11 @@
 - [`[temperature_fan] reverse: True`](./Config_Reference.md#temperature_fan) will let you control a fan in reverse to temperature control. The lower the temperature, the higher the fan runs.
 - Fans now normalize PWM power within `off_below` and `max_power`, so setting a fan to 10% will get you 10% fan speed within your configured off/max range.
 
+
+## TMC Drivers
+
+- [`[tmc2240] driver_CS and current_range`](./Config_Reference.md#tmc2240) let you tune the current scaler and current range of your tmc2240 drivers.
+
 ## Macros
 
 - The jinja `do` extension has been enabled. You can now call functions in your macros without resorting to dirty hacks: `{% do array.append(5) %}`

klippy/extras/tmc.py

@@ -773,13 +773,14 @@ def TMCStealthchopHelper(config, mcu_tmc, tmc_freq):
 
 
 class BaseTMCCurrentHelper:
-    def __init__(self, config, mcu_tmc, max_current):
+    def __init__(self, config, mcu_tmc, max_current, has_sense_resistor=True):
         self.printer = config.get_printer()
         self.name = config.get_name().split()[-1]
         self.mcu_tmc = mcu_tmc
         self.fields = mcu_tmc.get_fields()
 
-        self.sense_resistor = config.getfloat("sense_resistor", above=0.0)
+        if has_sense_resistor:
+            self.sense_resistor = config.getfloat("sense_resistor", above=0.0)
 
         # config_{run|hold|home}_current
         # represents an initial value set via config file

klippy/extras/tmc2240.py

@@ -263,37 +263,30 @@
 # TMC stepper current config helper
 ######################################################################
 
+KIFS = [11750.0, 24000.0, 36000.0, 36000.0]
+GLOBALSCALER_ERROR = (
+    "[tmc2240 %s]\n"
+    "GLOBALSCALER(%d) calculation out of bounds.\n"
+    "The target current can't be achieved with the given RREF(%f) "
+    "and CS(%d). Please adjust your configuration.\n"
+    "Calculated current_range bit: %s\n"
+    "Calculated KIFS: %s"
+)
+
 
 class TMC2240CurrentHelper(tmc.BaseTMCCurrentHelper):
     def __init__(self, config, mcu_tmc):
-        self.printer = config.get_printer()
-        self.name = config.get_name().split()[-1]
-        self.mcu_tmc = mcu_tmc
-        self.fields = mcu_tmc.get_fields()
         self.Rref = config.getfloat("rref", minval=12000.0, maxval=60000.0)
-        self.max_current = self._get_ifs_rms(3)
-        self.config_run_current = config.getfloat(
-            "run_current", above=0.0, maxval=self.max_current
-        )
-        self.config_hold_current = config.getfloat(
-            "hold_current", self.max_current, above=0.0, maxval=self.max_current
-        )
-        self.config_home_current = config.getfloat(
-            "home_current",
-            self.config_run_current,
-            above=0.0,
-            maxval=self.max_current,
+        super().__init__(
+            config, mcu_tmc, self._get_ifs_rms(3), has_sense_resistor=False
         )
-        self.current_change_dwell_time = config.getfloat(
-            "current_change_dwell_time", 0.5, above=0.0
-        )
-        self.req_run_current = self.config_run_current
-        self.req_hold_current = self.config_hold_current
-        self.req_home_current = self.config_home_current
 
-        self.actual_current = self.req_run_current
         current_range = self._calc_current_range(self.actual_current)
-        self.fields.set_field("current_range", current_range)
+        self.current_range = config.getint(
+            "current_range", current_range, minval=current_range, maxval=3
+        )
+        self.fields.set_field("current_range", self.current_range)
+        self.cs = config.getint("driver_CS", 31, minval=0, maxval=31)
         gscaler, irun, ihold = self._calc_current(
             self.req_run_current, self.req_hold_current
         )
@@ -304,7 +297,6 @@ def __init__(self, config, mcu_tmc):
     def _get_ifs_rms(self, current_range=None):
         if current_range is None:
             current_range = self.fields.get_field("current_range")
-        KIFS = [11750.0, 24000.0, 36000.0, 36000.0]
         return (KIFS[current_range] / self.Rref) / math.sqrt(2.0)
 
     def _calc_current_range(self, current):
@@ -315,25 +307,30 @@ def _calc_current_range(self, current):
 
     def _calc_globalscaler(self, current):
         ifs_rms = self._get_ifs_rms()
-        globalscaler = int(((current * 256.0) / ifs_rms) + 0.5)
-        globalscaler = max(32, globalscaler)
-        if globalscaler >= 256:
-            globalscaler = 0
-        return globalscaler
-
-    def _calc_current_bits(self, current, globalscaler):
-        ifs_rms = self._get_ifs_rms()
-        if not globalscaler:
-            globalscaler = 256
-        cs = int(
-            (current * 256.0 * 32.0) / (globalscaler * ifs_rms) - 1.0 + 0.5
+        globalscaler = math.floor(
+            (current * 256.0 * 32) / (ifs_rms * (self.cs + 1))
         )
-        return max(0, min(31, cs))
+        if globalscaler == 256:
+            return 0
+        if 1 <= globalscaler <= 31 or globalscaler > 256:
+            current_range = self.fields.get_field("current_range")
+            self.printer.invoke_shutdown(
+                GLOBALSCALER_ERROR
+                % (
+                    self.name,
+                    globalscaler,
+                    self.Rref,
+                    self.cs,
+                    f"{current_range:02b}",
+                    f"{(KIFS[current_range] / 1000):.2f}",
+                )
+            )
+        return globalscaler
 
     def _calc_current(self, run_current, hold_current):
         gscaler = self._calc_globalscaler(run_current)
-        irun = self._calc_current_bits(run_current, gscaler)
-        ihold = self._calc_current_bits(min(hold_current, run_current), gscaler)
+        irun = self.cs
+        ihold = math.floor((min((hold_current / run_current) * irun, irun)))
         return gscaler, irun, ihold
 
     def _calc_current_from_field(self, field_name):

test/klippy/tmc.cfg

@@ -98,6 +98,8 @@ rotation_distance: 8
 cs_pin: PK3
 run_current: .5
 rref: 12000
+driver_CS: 30
+current_range: 0
 
 [mcu]
 serial: /dev/ttyACM0