add airspy support without soapy

not sure airspy is really a good fit but everyones needs are different

Author: wiedehopf

README.md

@@ -54,6 +54,7 @@ services:
 | `RTL_SERIAL`             | The rtlsdr device serial that identifies your dongle.                                                                                                                            | No       | Blank              |
 | `BIASTEE`                | Enable biastee when using RTL_SERIAL (doesn't work with SOAPY).                                                                                                                  | No       | Blank              |
 | `SOAPYSDR`               | The SoapySDR device string that identifies your dongle. See below for supported soapy sdr types.                                                                                 | No       | Blank              |
+| `AIRSPY_SERIAL`          | The airspy device serial that identifies your dongle (LNA recommended, really just use an rtl-sdr maybe).                                                                        | No       | Blank              |
 | `FEED_ID`                | Used by the decoder to insert a unique ID in to the output message                                                                                                               | Yes      | Blank              |
 | `FREQUENCIES`            | Semicolon-separated or space-separated list of frequencies in MHz for the decoder to listen to                                                                                   | Yes      | Blank              |
 | `PPM`                    | Parts per million correction of the decoder                                                                                                                                      | No       | 0                  |

rootfs/etc/s6-overlay/scripts/01-acarsdec

@@ -50,8 +50,8 @@ if [[ -n "${GAIN}" ]] && [[ "$(awk '{if ($1 > 0 && $1 < 100) printf "%i", $1 * 1
 	exit 1
 fi
 
-if [[ -z "${SOAPYSDR}" ]] && [[ -z "${RTL_SERIAL}" ]] && [[ -z "${SERIAL}" ]] ; then
-    "${s6wrap[@]}" echo "Either RTL_SERIAL or SOAPYSDR must be set, exiting"
+if [[ -z "${SOAPYSDR}" ]] && [[ -z "${RTL_SERIAL}" ]] && [[ -z "${SERIAL}" ]] && [[ -z "${AIRSPY_SERIAL}" ]]; then
+    "${s6wrap[@]}" echo "Either RTL_SERIAL or SOAPYSDR or AIRSPY_SERIAL must be set, exiting"
 fi
 
 mkdir -p /run/acars

rootfs/etc/s6-overlay/scripts/acarsdec

@@ -56,6 +56,15 @@ if [[ -n "${RTL_SERIAL}" ]]; then
     fi
 fi
 
+if [[ -n "${AIRSPY_SERIAL}" ]]; then
+	ACARS_CMD+=("--airspy" "${AIRSPY_SERIAL}")
+    if chk_enabled "${BIASTEE}"; then
+        ACARS_CMD+=("-B" "1")
+    else
+        ACARS_CMD+=("-B" "0")
+    fi
+fi
+
 if [ -n "${PPM}" ]; then
 	ACARS_CMD+=("-p" "$PPM")
 fi