Port heaterX code from KPF to camerad 2.0

Config/cameraserver.cfg

@@ -4,6 +4,8 @@ ARCHON_IP=192.168.1.2
 ARCHON_PORT=4242
 DEFAULT_FIRMWARE=/home/user/Software/acf/kpf-getimage-slot5.acf
 EXPOSE_PARAM=Expose               # Archon parameter which triggers exposure
+#HEATER_TARGET_MIN=-150           # heater target lower limit (C)
+#HEATER_TARGET_MAX=50             # heater target upper limit (C)
 IMDIR=/tmp                        # base directory to save images
 BASENAME=image                    # base image filename
 NBPORT=3030                       # server non-blocking port

README.md

@@ -75,6 +75,54 @@ If you encounter any problems or have questions about this project, please open
     $ ../bin/run_unit_tests
     ```
 
+## Heater & Sensor Control
+
+For Archon **Heater** and **HeaterX** modules, the server exposes commands to
+control the closed-loop heaters and read/control the on-board temperature
+sensors. These require firmware to be loaded and a sufficiently recent Archon
+backplane.
+
+### `heater`
+
+Control heater `A` or `B` on the given module: enable state and target, PID
+parameters, ramp, current limit, and input sensor.
+
+```
+heater <module> <A|B> [ <on|off> [target] | <target> | PID [<p> <i> <d>]
+                        | RAMP [<on|off> [rate]] | ILIM [val] | INPUT [A|B|C] ]
+```
+
+| Form                                   | Effect                                                  |
+|----------------------------------------|---------------------------------------------------------|
+| `heater <module> <A\|B>`                | get enable state and target                             |
+| `heater <module> <A\|B> <on\|off> [target]` | set enable state, optionally the target            |
+| `heater <module> <A\|B> <target>`       | set the target (range depends on backplane version)     |
+| `heater <module> <A\|B> PID [<p> <i> <d>]` | get/set the P, I, D parameters (`0`–`10000` each)    |
+| `heater <module> <A\|B> RAMP [<on\|off> [rate]]` | get/set ramp enable and ramprate (`1`–`32767`)  |
+| `heater <module> <A\|B> ILIM [val]`     | get/set the current limit (`0`–`10000`)                 |
+| `heater <module> <A\|B> INPUT [A\|B\|C]` | get/set the input sensor (`C` requires HeaterX)        |
+
+The target range defaults to backplane-version-dependent limits and can be
+overridden in the `.cfg` file with `HEATER_TARGET_MIN` / `HEATER_TARGET_MAX`
+(degrees C).
+
+### `sensor`
+
+Set or get a temperature sensor's RTD excitation current and digital averaging.
+
+```
+sensor <module> <A|B|C> [ <current> | AVG [ <N> ] ]
+```
+
+| Form                              | Effect                                                        |
+|-----------------------------------|--------------------------------------------------------------|
+| `sensor <module> <A\|B\|C>`        | get the excitation current (nano-amps)                       |
+| `sensor <module> <A\|B\|C> <current>` | set the excitation current, `0`–`1600000` nA             |
+| `sensor <module> <A\|B\|C> AVG`    | get the digital averaging count                              |
+| `sensor <module> <A\|B\|C> AVG <N>`| set the digital averaging count `N` ∈ {1,2,4,8,…,256}        |
+
+Sensor `C` is available only on **HeaterX** modules.
+
 ---
 
 David Hale