diff --git a/v5_field_control.ino b/v5_field_control.ino
index 0286bc4..b9dd88a 100644
--- a/v5_field_control.ino
+++ b/v5_field_control.ino
@@ -7,11 +7,14 @@
 
   https://www.arduino.cc/en/Tutorial/BuiltInExamples/DigitalReadSerial
 */
-#include <SPI.h>
-#include <Wire.h>
-
 #include "CRC16.h"
 
+volatile uint8_t control_flags = 0xC9;
+volatile uint32_t timer_end = 0x00000000;
+volatile uint32_t length = 0x00000000;
+volatile uint32_t last_timer_sent = 0x00000000;
+CRC16 crc = CRC16(0x1021, 0xFFFF, 0x0000, false, false);
+
 int read_line = 22;
 
 int rx2 = 16;
@@ -65,7 +68,17 @@ typedef struct __attribute__((packed)) {
   uint16_t crc;
 } pkt_set_poll_rate_t;
 
-CRC16 crc = CRC16(0x1021, 0xFFFF, 0x0000, false, false);
+typedef struct __attribute__((packed)) {
+  uint8_t type;
+  uint8_t unknown_1;
+  uint16_t system_status;
+  uint8_t unknown_2[2];
+  uint8_t field_status;
+  uint8_t unknown_3[11];
+  uint8_t name[10];
+  uint8_t version[2];
+  uint16_t crc;
+} pkt_poll_t;
 
 void parse_discovery(uint8_t* pkt, size_t len) {
   pkt_discovery_t parsed;
@@ -142,9 +155,9 @@ void parse_get_poll_rate(uint8_t* pkt, size_t len, uint8_t poll_ms) {
   uint16_t calc_crc = crc.calc();
 
   if (parsed_crc != calc_crc) {
-    Serial.printf("Got init_3 packet with bad crc(%04x != %04x\n", calc_crc, parsed_crc);
+    Serial.printf("Got get_poll_rate packet with bad crc(%04x != %04x\n", calc_crc, parsed_crc);
   } else {
-    Serial.printf("Got init_3 packet with matching crc(%04x)\n", calc_crc);
+    Serial.printf("Got get_poll_rate packet with matching crc(%04x)\n", calc_crc);
   }
 
   pkt_set_poll_rate_t response;
@@ -190,10 +203,10 @@ void send_state(uint8_t control_flags, uint32_t timer) {
   response[1] = control_flags;
   response[2] = 0x00;
   response[3] = 0x00;
-  response[4] = (timer >> 24 & 0xFF);
-  response[5] = (timer >> 16 & 0xFF);
-  response[6] = (timer >>  8 & 0xFF);
-  response[7] = (timer >>  0 & 0xFF);
+  response[4] = ((timer >>  0) & 0xFF);
+  response[5] = ((timer >>  8) & 0xFF);
+  response[6] = ((timer >> 16) & 0xFF);
+  response[7] = ((timer >> 24) & 0xFF);
   response[8] = 0x03;
 
   crc.restart();
@@ -209,22 +222,6 @@ void send_state(uint8_t control_flags, uint32_t timer) {
   digitalWrite(read_line, LOW);
 }
 
-typedef struct __attribute__((packed)) {
-  uint8_t type;
-  uint8_t unknown_1;
-  uint16_t system_status;
-  uint8_t unknown_2[2];
-  uint8_t field_status;
-  uint8_t unknown_3[11];
-  uint8_t name[10];
-  uint8_t version[2];
-  uint16_t crc;
-} pkt_poll_t;
-
-volatile uint8_t control_flags = 0xC9;
-volatile uint32_t timer = 0x00002000;
-#define POLL_COUNT_MAX 5
-
 void parse_poll(uint8_t* pkt, size_t len) {
   pkt_poll_t* parsed = (pkt_poll_t*)pkt;
   crc.restart();
@@ -237,10 +234,22 @@ void parse_poll(uint8_t* pkt, size_t len) {
     //Serial.printf("parsed poll with valid CRC 0x%04x, system status 0x%04x, field status 0x%02x, team name %s\n", htons(parsed->crc), htons(parsed->system_status), parsed->field_status, parsed->name);
   }
 
-  if (parsed->field_status == control_flags) {
+  uint32_t now = millis();
+  uint32_t current_timer = 0;
+  if (now < timer_end) {
+    current_timer = (timer_end - millis()) & 0xFFFFFF00;
+  } else {
+    current_timer = length;
+    control_flags = 0xC9;
+  }
+
+  if ((parsed->field_status == control_flags) && (current_timer == last_timer_sent)) {
     send_ack(0xA7, 0x01);
-  } {
-    send_state(control_flags, timer);
+  } else if (control_flags == 0xC9) {
+    send_state(0xC9, length);
+  } else {
+    last_timer_sent = current_timer;
+    send_state(control_flags, current_timer);
   }
 }
 
@@ -251,8 +260,9 @@ void on_rx(void) {
     return;
   }
   int read = Serial.readBytes(pkt, n);
-  sscanf((const char*)pkt, "0x%2hhx", &control_flags);
-  Serial.printf("Parsed new control flags: 0x%02x\n",  control_flags);
+  sscanf((const char*)pkt, "0x%2hhx%8x", &control_flags, &length);
+  timer_end = millis() + length;
+  Serial.printf("Parsed new control flags: 0x%02x, length 0x%08x\n",  control_flags, length);
 }
 
 void on_rx_2(void) {
@@ -273,7 +283,7 @@ void on_rx_2(void) {
     parse_init(pkt, read);
     break;
   case 0x11:
-    parse_get_poll_rate(pkt, read, 50);
+    parse_get_poll_rate(pkt, read, 20);
     break;
   case 0x02:
     switch (pkt[1]){