Detail for my sketch remoteUnit_fasterControl_1.ino

/* remoteUnit_fasterControl_1.ino
 *
 * This sketch is to control a remote load for a Mk2 PV Router at the receiver end
 * of an RF link.  If RF transmission is lost, the load is turned off.  A repeater
 * signal is available at the 'mode' connector.  This is intended to drive an LED
 * with an appropriate series resistor, e.g. 120R. 
 *
 * The ability to measure and display the amount of energy which has been diverted 
 * via the remote load is included.  For this to happen, one of the live cores
 * needs to pass through a CT which connects to the 'CT2' connector.  
 *
 * The 'CT1' connector has been re-used in this sketch to provide a 2-colour 
 * indication of the state of the RF link.  A schematic for this circuit may be 
 * found immediately below this header.
 *
 * A persistence-based 4-digit display is supported. When the RFM12B module is 
 * in use, the display can only be used in conjunction with an extra pair of 
 * logic chips.  These are ICs 3 and 4, which reduce the number of processor pins 
 * that are needed to drive the display.
 *
 * This sketch is similar in function to RF_for_Mk2_rx.ino, as posted on the 
 * OpenEnergyMonitor forum.  That version, and other related material, can be
 * found on my Summary Page at www.openenergymonitor.org/emon/node/1757
 *
 * January 2016: renamed as remote_Mk2_receiver_1a, with a minor change in the ISR to 
 * remove a timing uncertainty.  Support for the RF69 RF module has also been included.
 *
 * January 2016: updated to remote_Mk2_receiver_1b:
 *   The variables to store the ADC results are now declared as "volatile" to remove 
 *   any possibility of incorrect operation due to optimisation by the compiler.
 *
 * February 2016: updated to remote_Mk2_receiver_2, with these changes:
 * - improvements to the start-up logic.  The start of normal operation is now 
 *    synchronised with the start of a new mains cycle.
 * - reduce the amount of feedback in the Low Pass Filter for removing the DC content
 *     from the Vsample stream. This resolves an anomaly which has been present since 
 *     the start of this project.  Although the amount of feedback has previously been 
 *     excessive, this anomaly has had minimal effect on the system's overall behaviour.
 * - change all instances of "triac" to "load"
 *
 * September 2022: updated to remoteUnit_fasterConrol_1, with this change:
 * - RF payload reduced to just one integer for the load state. For use with the transmitter
 *   sketch, Mk2_fasterControl_withRemoteLoad_n
 * - the hardware timer that controls the ADC has been increased from 200 to 250 us (just to  
 *   reduce the workload).
 * 
 *       Robin Emley
 *      www.Mk2PVrouter.co.uk
 */