sendHeartbeat
Send a heartbeat packet with a monotonically-increasing nonce to keep the connection alive. Starts at HeartbeatSender.FIRST_NONCE, past the firmware's NodeInfo-ping trigger.
Send a heartbeat packet with a monotonically-increasing nonce to keep the connection alive. Starts at HeartbeatSender.FIRST_NONCE, past the firmware's NodeInfo-ping trigger.