Hola, las respuestas son las siguientes:
1.
http://<<servidor>>/opengarden.php: ERR_LOGIN. Si abro primero la app y entro con admin y 12345 en otra pestaña, ya sale;
QUERY: SELECT node_id, node_type, max(date) as date, max(date) > (NOW() - INTERVAL 1 HOUR) as online FROM measurements GROUP BY node_id
ERROR: Expression #2 of SELECT list is not in GROUP BY clause and contains nonaggregated column 'opengarden.measurements.node_type' which is not functionally dependent on columns in GROUP BY clause; this is incompatible with sql_mode=only_full_group_by
No se si será relevante, pero para las pruebas estoy recogiendo medidas cada minuto.
2.
http://<<servidor>>/opengarden.php?node=1: ERR_LOGIN. Ídem
[{"node_id":"1","sensor_type":"Battery level","value":"3952","date":"2017-03-27 18:52:27","unit":"mV"},{"node_id":"1","sensor_type":"Soil Moisture","value":"0","date":"2017-03-27 18:54:03","unit":"%"},{"node_id":"1","sensor_type":"Air Humidity","value":"0.0","date":"2017-03-27 18:54:03","unit":"%RH"},{"node_id":"1","sensor_type":"Air Temperature ","value":"0.0","date":"2017-03-27 18:54:03","unit":"\u00baC"},{"node_id":"1","sensor_type":"Light level","value":"0","date":"2017-03-27 18:54:03","unit":"%"}]
*
http://<<servidor>>/opengarden.php?node=2: ERR_LOGIN. Ídem
[{"node_id":"2","sensor_type":"Battery level","value":"3966","date":"2017-03-27 18:52:27","unit":"mV"},{"node_id":"2","sensor_type":"Soil Moisture","value":"414","date":"2017-03-27 18:54:11","unit":"%"},{"node_id":"2","sensor_type":"Air Humidity","value":"56.5","date":"2017-03-27 18:54:11","unit":"%RH"},{"node_id":"2","sensor_type":"Air Temperature ","value":"22.3","date":"2017-03-27 18:54:11","unit":"\u00baC"},{"node_id":"2","sensor_type":"Light level","value":"0","date":"2017-03-27 18:54:11","unit":"%"}]
*
http://<<servidor>>/opengarden.php?node=0: ERR_LOGIN. Ídem
[{"node_id":"0","sensor_type":"Air Humidity","value":"40.9","date":"2017-03-25 12:50:57","unit":"%RH"},{"node_id":"0","sensor_type":"Air Temperature ","value":"21.6","date":"2017-03-25 12:50:57","unit":"\u00baC"},{"node_id":"0","sensor_type":"Light level","value":"17","date":"2017-03-25 12:50:57","unit":"%"},{"node_id":"0","sensor_type":"Soil Moisture","value":"876","date":"2017-03-25 12:50:57","unit":"%"}][{"node_id":"0","sensor_type":"Light level","value":"10","date":"2017-03-27 17:47:52","unit":"%"},{"node_id":"0","sensor_type":"Soil Moisture","value":"0","date":"2017-03-27 18:53:55","unit":"%"},{"node_id":"0","sensor_type":"Soil temperature","value":"-127.0","date":"2017-03-27 18:53:55","unit":"\u00baC"},{"node_id":"0","sensor_type":"Air Humidity","value":"52.6","date":"2017-03-27 18:53:55","unit":"%RH"},{"node_id":"0","sensor_type":"Air Temperature ","value":"23.2","date":"2017-03-27 18:53:55","unit":"\u00baC"}]
Lo datos obtenidos son correctos, ya que el gateway lleva acoplados un sensor de humedad del suelo y uno de temperatura y humedad del aire. El nodo 1 tiene acoplado un sensor de humedad del suelo y el nodo 2 uno de temperatura y humedad del aire.
Ya me decís. Gracias.