A little helper: decode ASCII payload

Author: gotthardp

doc/Handlers.md

@@ -25,6 +25,7 @@ To create a new handler you need to set:
  - **Application** name
  - **Uplink Fields** that will be forwarded to the backend Connector
  - **Payload** format for automatic decoding
+   - **ASCII Text**
    - [**Cayenne LPP**](https://github.com/myDevicesIoT/cayenne-docs/blob/master/docs/LORA.md)
  - **Parse Uplink** function to extract additional data fields from the uplink frame
  - **Event Fields** that will be forwarded to the backend Connector
@@ -149,6 +150,10 @@ The server can auto-parse some well-known data formats.
 To parse a custom format leave the *Payload* field undefined and write own
 *Parse Uplink* function.
 
+### ASCII Text
+
+The payload will get stored into the `text` field as ASII characters.
+
 ### Cayenne Low Power Payload (LPP)
 
 For each Data Channel *N* the server will create a `fieldN` with the parsed value.

priv/admin/admin.js

@@ -813,6 +813,7 @@ myApp.config(['NgAdminConfigurationProvider', function (nga) {
             ]),
         nga.field('payload', 'choice')
             .choices([
+                { value: 'ascii', label: 'ASCII Text' },
                 { value: 'cayenne', label: 'Cayenne LPP' }
             ]),
         nga.field('parse_uplink', 'text'),

src/lorawan_application_backend.erl

@@ -278,6 +278,8 @@ filter_group_responses(_AppID, List) ->
         end,
         ok, List).
 
+parse_payload(<<"ascii">>, Data) ->
+    #{text => Data};
 parse_payload(<<"cayenne">>, Data) ->
     cayenne_decode(Data);
 parse_payload(None, _Data) when None == <<>>; None == undefined ->