AP_Scripting: added CANDRV to HFE EFI driver and document

libraries/AP_Scripting/drivers/EFI_HFE.lua

@@ -3,7 +3,7 @@
 --]]
 
 -- Check Script uses a miniumum firmware version
-local SCRIPT_AP_VERSION = 4.4
+local SCRIPT_AP_VERSION = 4.3
 local SCRIPT_NAME       = "EFI: HFE CAN"
 
 local VERSION = FWVersion:major() + (FWVersion:minor() * 0.1)
@@ -54,30 +54,38 @@ function constrain(v, vmin, vmax)
     return v
 end
 
--- Register for the CAN drivers
-local driver1 = CAN.get_device(25)
-
-if not driver1 then
-    gcs:send_text(0, string.format("EFI_HFE: Failed to load driver"))
-    return
-end
-
 local efi_backend = nil
 
 -- Setup EFI Parameters
-assert(param:add_table(PARAM_TABLE_KEY, PARAM_TABLE_PREFIX, 5), 'could not add EFI_HFE param table')
+assert(param:add_table(PARAM_TABLE_KEY, PARAM_TABLE_PREFIX, 6), 'could not add EFI_HFE param table')
 
 local EFI_HFE_ENABLE = bind_add_param('ENABLE',  1, 0)
 local EFI_HFE_RATE_HZ  = bind_add_param('RATE_HZ',  2, 200)    -- Script update frequency in Hz
 local EFI_HFE_ECU_IDX = bind_add_param('ECU_IDX',  3, 0)   -- ECU index on CAN bus, 0 for automatic
 local EFI_HFE_FUEL_DTY = bind_add_param('FUEL_DTY',  4, 740)   -- fuel density, g/litre
 local EFI_HFE_REL_IDX = bind_add_param('REL_IDX',  5, 0)   -- relay number for engine enable
+local EFI_HFE_CANDRV = bind_add_param('CANDRV',  6, 0)   -- CAN driver number
+
 local ICE_PWM_IGN_ON = bind_param("ICE_PWM_IGN_ON")
 
 if EFI_HFE_ENABLE:get() == 0 then
    return
 end
 
+-- Register for the CAN drivers
+local CAN_BUF_LEN = 25
+if EFI_HFE_CANDRV:get() == 1 then
+   driver1 = CAN.get_device(CAN_BUF_LEN)
+elseif EFI_HFE_CANDRV:get() == 2 then
+   driver1 = CAN.get_device2(CAN_BUF_LEN)
+end
+
+if not driver1 then
+    gcs:send_text(0, string.format("EFI_HFE: Failed to load driver"))
+    return
+end
+
+
 local now_s = get_time_sec()
 
 --[[

libraries/AP_Scripting/drivers/EFI_HFE.md

@@ -0,0 +1,65 @@
+# EFI HFE Driver
+
+This driver implements support for the HFE International range of EFI
+CAN engine control units. It supports monitoring and control of HFE
+engines on fixed wing aircraft. This driver assumes you are using the
+ICE subsystem in fixed wing aircraft for engine control.
+
+# Parameters
+
+The script used the following parameters:
+
+## EFI_HFE_ENABLE
+
+this must be set to 1 to enable the driver
+
+## EFI_HFE_CANDRV
+
+This sets the CAN scripting driver number to attach to. This is
+normally set to 1 to use a CAN driver with CAN_Dx_PROTOCOL=10. To use
+the 2nd scripting CAN driver set this to 2 and set CAN_Dx_PROTOCOL=12.
+
+## EFI_HFE_ECU_IDX
+
+This sets the ECU number on the CAN bus. A value of zero means that
+the ECU number is auto-detected based on the first ECU seen on the
+bus.
+
+## EFI_HFE_RATE_HZ
+
+This sets the update rate of the driver. A value of 200 is reasonable
+
+## EFI_HFE_FUEL_DTY
+
+This sets the fuel density in grams per litre, for fuel consumption
+calculations
+
+## EFI_HFE_REL_IDX
+
+This sets a relay number to use for the ECU enable function. if the
+ECU requires a high voltage GPIO to enable then you should set a
+RELAY_PIN that the ECU enable is attached to and set the relay number
+here.
+
+# Operation
+
+This driver should be loaded by placing the lua script in the
+APM/SCRIPTS directory on the microSD card, which can be done either
+directly or via MAVFTP. The following key parameters should be set:
+
+ - SCR_ENABLE should be set to 1
+ - EFI_TYPE should be set to 7
+ - ICE_ENABLE should be set to 1
+
+then the flight controller should rebooted and parameters should be
+refreshed.
+
+Once loaded the EFI_HFE parameters will appear and should be set
+according to the parameter list above.
+
+The ICE start channel will be monitored for starter control.
+
+The GCS will receive EFI_STATUS MAVLink messages which includes RPM,
+cylinder head temperature, injection timing, engine load, fuel
+consumption rate, throttle position atmospheric pressure and ECU
+voltage.