added auto gain

src/dodal/devices/current_amplifiers/femto.py

@@ -1,3 +1,4 @@
+import asyncio
 from enum import Enum
 
 from bluesky.protocols import Movable, Reading
@@ -14,7 +15,7 @@
 from dodal.log import LOGGER
 
 
-class Fmeto100(str, Enum):
+class Femto100(str, Enum):
     sen_1 = "10^4"
     sen_2 = "10^5"
     sen_3 = "10^6"
@@ -33,8 +34,8 @@ class Fmeto100(str, Enum):
 class Femto(StandardReadable, Movable):
     def __init__(self, prefix: str, name: str = "") -> None:
         with self.add_children_as_readables(HintedSignal):
-            self.gain = epics_signal_rw(Fmeto100, prefix + "GAIN")
-            self.current = soft_signal_r_and_setter(
+            self.gain = epics_signal_rw(Femto100, prefix + "GAIN")
+            self.current, self._current_set = soft_signal_r_and_setter(
                 float, initial_value=None, units="Amp"
             )
         with self.add_children_as_readables(ConfigSignal):
@@ -44,29 +45,35 @@ def __init__(self, prefix: str, name: str = "") -> None:
 
     @AsyncStatus.wrap
     async def set(self, value) -> None:
-        if self.auto_mode.get_value is True:
-            LOGGER.info(f"{self.name}-Attempting auto-gain")
-            await self.auto_gain()
-
-        self._set(value=value, timeout=TIMEOUT)
-
-    @AsyncStatus.wrap
-    async def _set(self, value, timeout=TIMEOUT) -> None:
-        self.gain.set(value=value, timeout=timeout)
+        self.gain.set(value=value, timeout=TIMEOUT)
 
     async def read(self) -> dict[str, Reading]:
-        self.current = await self.analogue_readout.get_value() * float(
-            await self.gain.get_value()
-        )
+        if await self.auto_mode.get_value() is True:
+            LOGGER.info(f"{self.name}-Attempting auto-gain")
+            await self.auto_gain()
+        gain_value = 10 ** float((await self.gain.get_value()).value.split("^")[1])
+        self._current_set(await self.analogue_readout.get_value() / gain_value)
         return await super().read()
 
     async def auto_gain(self) -> bool:
+        cnt = 0
+        success = True
+        while success and cnt < len(Femto100):
+            reading = await self.analogue_readout.get_value(cached=False)
+            if reading > 9.8:
+                current_gain = int((await self.gain.get_value()).name.split("_")[1])
+                current_gain -= 1
+                if current_gain < 1:
+                    return False
+                self.set(value=Femto100[f"sen_{current_gain}"])
+            elif reading < 0.8:
+                current_gain = int((await self.gain.get_value()).name.split("_")[1])
+                current_gain += 1
+                if current_gain > len(Femto100):
+                    return False
+                self.set(value=Femto100[f"sen_{current_gain}"])
+            else:
+                return True
+            await asyncio.sleep(0.5)
+            cnt += 1
         return True
-        # check if analogure readout is within range
-        # if so done
-        # else
-        #    change gain until it is within range
-        #    or
-        #    when it hit the edge of the range
-        #    or
-        #    when it tried the entire range.