diff --git a/prime-tx/main.c b/prime-tx/main.c
index 512688f..68ea4c1 100644
--- a/prime-tx/main.c
+++ b/prime-tx/main.c
@@ -43,7 +43,6 @@ int main(void) {
     int clock = 0;
     uint8_t primes[] = { 1, 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97, 0 };
 
-    /*
     display_t display = {
         .reg = {
             .output         = { .ddr = &DDRB, .port = &PORTB, .pin = &PINB, .addr = 7 },
@@ -51,7 +50,6 @@ int main(void) {
             .latch_clock    = { .ddr = &DDRB, .port = &PORTB, .pin = &PINB, .addr = 5 },
         },
     };
-    */
 
     rfm_t radio = (rfm_t){
         .spi    = {
@@ -64,23 +62,23 @@ int main(void) {
         .reset  = { .ddr = &DDRD, .port = &PORTD, .pin = &PIND, .addr = 4 },
     };
 
-    // _delay_ms(15);
-    // display_init(&display);
+    _delay_ms(15);
+    display_init(&display);
 
     rfm_error_e error;
 
     rfm_init(&radio, (uint8_t [4]){ 0xde, 0xca, 0xfb, 0xad }, 4, &error);
 
-    // status(&display, &radio, clock);
+    status(&display, &radio, clock);
 
     int next_transmit = 0;
     int prime = 0;
     while (1) {
         if (clock >= next_transmit) {
-            // display_clear(&display);
+            display_clear(&display);
             char msg[16];
             sprintf(msg, "sending %d", primes[prime]);
-            // display_write_message(&display, msg);
+            display_write_message(&display, msg);
             rfm_transmit(&radio, &primes[prime], 1);
             if (primes[prime] == 0) {
                 prime = 0;
@@ -90,7 +88,7 @@ int main(void) {
             next_transmit = clock + 10;
             _delay_ms(1000);
         }
-        // status(&display, &radio, clock);
+        status(&display, &radio, clock);
         interrupt_flags_t flags = rfm_interrupts(&radio);
 
         if (flags.packet_sent) {
diff --git a/rfm69hcw/rfm.c b/rfm69hcw/rfm.c
index 2d9ffe8..622ffca 100644
--- a/rfm69hcw/rfm.c
+++ b/rfm69hcw/rfm.c
@@ -122,8 +122,9 @@ void rfm_standby(rfm_t *rfm) {
     rfm_set_mode(rfm, (op_mode_t){ .listen_on = false, .mode = standby });
 }
 
-void rfm_transmit(rfm_t *rfm, uint8_t *data, size_t length) {
+void rfm_transmit(rfm_t *rfm, uint8_t *data, uint8_t length) {
     rfm_set_mode(rfm, (op_mode_t){ .listen_on = false, .mode = standby });
+    _rfm_write(rfm, REG_FIFO, &length, 1);
     _rfm_write(rfm, REG_FIFO, data, length);
     _rfm_write(rfm, REG_DIO_MAPPING1, (uint8_t [1]){ 0x00 }, 1);
     rfm_set_mode(rfm, (op_mode_t){ .listen_on = false, .mode = tx });
diff --git a/rfm69hcw/rfm.h b/rfm69hcw/rfm.h
index d3153d1..0c4e661 100644
--- a/rfm69hcw/rfm.h
+++ b/rfm69hcw/rfm.h
@@ -75,7 +75,7 @@ void rfm_packet_format(rfm_t *rfm, packet_format_e format, size_t length);
 void rfm_sleep(rfm_t *);
 void rfm_standby(rfm_t *);
 void rfm_receive_mode(rfm_t *);
-void rfm_transmit(rfm_t *rfm, uint8_t *data, size_t length);
+void rfm_transmit(rfm_t *rfm, uint8_t *data, uint8_t length);
 void rfm_receive(rfm_t *rfm, uint8_t *data, size_t length);
 
 op_mode_t rfm_mode(rfm_t *rfm);