diff --git a/include/sx127x.h b/include/sx127x.h
index 6b9591f..7ec9bd3 100644
--- a/include/sx127x.h
+++ b/include/sx127x.h
@@ -685,7 +685,7 @@ int sx127x_lora_tx_set_for_transmission(const uint8_t *data, uint8_t data_length
  *         - SX127X_ERR_INVALID_ARG   if parameter is invalid
  *         - SX127X_OK                on success
  */
-int sx127x_fsk_ook_tx_set_for_transmission(uint8_t *data, uint16_t data_length, sx127x *device);
+int sx127x_fsk_ook_tx_set_for_transmission(const uint8_t *data, uint16_t data_length, sx127x *device);
 
 /**
  * @brief Write packet into sx127x's FIFO for transmittion. Once packet is written, set opmod to TX.
@@ -698,7 +698,7 @@ int sx127x_fsk_ook_tx_set_for_transmission(uint8_t *data, uint16_t data_length,
  *         - SX127X_ERR_INVALID_ARG   if parameter is invalid
  *         - SX127X_OK                on success
  */
-int sx127x_fsk_ook_tx_set_for_transmission_with_address(uint8_t *data, uint16_t data_length, uint8_t address_to, sx127x *device);
+int sx127x_fsk_ook_tx_set_for_transmission_with_address(const uint8_t *data, uint16_t data_length, uint8_t address_to, sx127x *device);
 
 /**
  * @brief Start transmitting periodic beacon using FSK/OOK modulation. Packet format must be configured as SX127X_FIXED.
@@ -712,7 +712,7 @@ int sx127x_fsk_ook_tx_set_for_transmission_with_address(uint8_t *data, uint16_t
  *         - SX127X_ERR_INVALID_STATE if configured packet format is not SX127X_FIXED or selected modem is not FSK/OOK
  *         - SX127X_OK                on success
  */
-int sx127x_fsk_ook_tx_start_beacon(uint8_t *data, uint8_t data_length, uint32_t interval_ms, sx127x *device);
+int sx127x_fsk_ook_tx_start_beacon(const uint8_t *data, uint8_t data_length, uint32_t interval_ms, sx127x *device);
 
 /**
  * @brief Stop transmitting periodic beacon.
@@ -764,7 +764,7 @@ int sx127x_fsk_set_fdev(float frequency_deviation, sx127x *device);
  *         - SX127X_ERR_INVALID_ARG   if parameter is invalid
  *         - SX127X_OK                on success
  */
-int sx127x_fsk_ook_set_syncword(uint8_t *syncword, uint8_t syncword_length, sx127x *device);
+int sx127x_fsk_ook_set_syncword(const uint8_t *syncword, uint8_t syncword_length, sx127x *device);
 
 /**
  * @brief Set data whitening or scrambling is widely used for randomizing the user data before radio transmission. Scrambling can improve bit synchronizer accuracy.
diff --git a/src/sx127x.c b/src/sx127x.c
index 41e89ae..a1b6fce 100644
--- a/src/sx127x.c
+++ b/src/sx127x.c
@@ -922,7 +922,7 @@ int sx127x_fsk_ook_tx_set_for_transmission_with_remaining(uint16_t data_length,
   return sx127x_shadow_spi_write_buffer(REGFIFO, device->packet, to_send, &device->spi_device);
 }
 
-int sx127x_fsk_ook_tx_set_for_transmission(uint8_t *data, uint16_t data_length, sx127x *device) {
+int sx127x_fsk_ook_tx_set_for_transmission(const uint8_t *data, uint16_t data_length, sx127x *device) {
   CHECK_FSK_OOK_MODULATION(device);
   if (device->fsk_ook_format == SX127X_VARIABLE && data_length > MAX_PACKET_SIZE) {
     return SX127X_ERR_INVALID_ARG;
@@ -941,7 +941,7 @@ int sx127x_fsk_ook_tx_set_for_transmission(uint8_t *data, uint16_t data_length,
   return sx127x_fsk_ook_tx_set_for_transmission_with_remaining(data_length, device);
 }
 
-int sx127x_fsk_ook_tx_set_for_transmission_with_address(uint8_t *data, uint16_t data_length, uint8_t address_to, sx127x *device) {
+int sx127x_fsk_ook_tx_set_for_transmission_with_address(const uint8_t *data, uint16_t data_length, uint8_t address_to, sx127x *device) {
   CHECK_FSK_OOK_MODULATION(device);
   if (device->fsk_ook_format == SX127X_VARIABLE && data_length > (MAX_PACKET_SIZE - 1)) {
     return SX127X_ERR_INVALID_ARG;
@@ -962,7 +962,7 @@ int sx127x_fsk_ook_tx_set_for_transmission_with_address(uint8_t *data, uint16_t
   return sx127x_fsk_ook_tx_set_for_transmission_with_remaining(packet_length, device);
 }
 
-int sx127x_fsk_ook_tx_start_beacon(uint8_t *data, uint8_t data_length, uint32_t interval_ms, sx127x *device) {
+int sx127x_fsk_ook_tx_start_beacon(const uint8_t *data, uint8_t data_length, uint32_t interval_ms, sx127x *device) {
   CHECK_FSK_OOK_MODULATION(device);
   if (device->fsk_ook_format != SX127X_FIXED) {
     return SX127X_ERR_INVALID_STATE;
@@ -1161,7 +1161,7 @@ int sx127x_fsk_ook_rx_set_trigger(sx127x_rx_trigger_t trigger, sx127x *device) {
   return sx127x_append_register(REGRXCONFIG, trigger, 0b11111000, &device->spi_device);
 }
 
-int sx127x_fsk_ook_set_syncword(uint8_t *syncword, uint8_t syncword_length, sx127x *device) {
+int sx127x_fsk_ook_set_syncword(const uint8_t *syncword, uint8_t syncword_length, sx127x *device) {
   CHECK_FSK_OOK_MODULATION(device);
   if (syncword_length == 0 || syncword_length > 8) {
     return SX127X_ERR_INVALID_ARG;