Updating android widgets every 1 minute

Register an AlarmManager service for every 1 min call.

final Intent intent = new Intent(context, UpdateService.class);
final PendingIntent pending = PendingIntent.getService(context, 0, intent, 0);
final AlarmManager alarm = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE);
alarm.cancel(pending);
long interval = 1000*60;
alarm.setRepeating(AlarmManager.ELAPSED_REALTIME, SystemClock.elapsedRealtime(),interval, pending);

However, pushing updates to app widgets is an expensive operation. Updating every 1 min would force your "update an app widget" code to be resident in memory which keeps running all of the time, and this will also eat up battery pretty significantly.