diff --git a/boards/avsextrem/drivers/avsextrem-smb380.c b/boards/avsextrem/drivers/avsextrem-smb380.c
index 1803b8c686..2a8e20ef7e 100644
--- a/boards/avsextrem/drivers/avsextrem-smb380.c
+++ b/boards/avsextrem/drivers/avsextrem-smb380.c
@@ -794,15 +794,13 @@ int16_t SMB380_getBandWidthAbs(void)
 
 void SMB380_softReset(void)
 {
-    unsigned char ur;
     unsigned long cpsr = disableIRQ();
     SMB380_Prepare();
     SMB380_ssp_write(SMB380_CONTROL1, SMB380_CONTROL1_SOFT_RESET_MASK,
                      SMB380_WRITE_REGISTER);
-    ur = ((unsigned char)SMB380_ssp_read()) & SMB380_CONTROL1_SOFT_RESET_MASK;
+    SMB380_ssp_read();
     SMB380_Unprepare();
     restoreIRQ(cpsr);
-    ur = ur >> 1;
 }
 
 void SMB380_setCustomerReg(unsigned char data)
diff --git a/boards/redbee-econotag/tools/ftditools/bbmc.c b/boards/redbee-econotag/tools/ftditools/bbmc.c
index f0c7e0b032..55713febd4 100644
--- a/boards/redbee-econotag/tools/ftditools/bbmc.c
+++ b/boards/redbee-econotag/tools/ftditools/bbmc.c
@@ -473,6 +473,8 @@ int print_and_prompt(struct ftdi_device_list *devlist)
         size_t last = strlen(input) - 1;
 
         if (input[last] == '\n') {
+            /* cppcheck: input is accessed later via *s */
+            /* cppcheck-suppress unreadVariable */
             input[last] = '\0';
         }
 
@@ -534,7 +536,6 @@ void erase(struct ftdi_context *ftdic, const struct layout *l)
 int bb_mpsee(struct ftdi_context *ftdic, uint16_t dir, uint16_t val)
 {
     uint8_t buf[3];
-    int ret;
 
     /* command "set data bits low byte" */
     buf[0] = 0x80;
@@ -559,7 +560,7 @@ int bb_mpsee(struct ftdi_context *ftdic, uint16_t dir, uint16_t val)
     fprintf(stderr, "write %x %x %x\n", buf[0], buf[1], buf[2]);
 #endif
 
-    if ((ret = (ftdi_write_data(ftdic, buf, 3))) < 0) {
+    if ((ftdi_write_data(ftdic, buf, 3)) < 0) {
         perror("ft2232_write error");
         fprintf(stderr, "ft2232_write command %x\n", buf[0]);
         return EXIT_FAILURE;
diff --git a/cpu/atmega2560/periph/uart.c b/cpu/atmega2560/periph/uart.c
index ae08130287..d570ca8fd8 100644
--- a/cpu/atmega2560/periph/uart.c
+++ b/cpu/atmega2560/periph/uart.c
@@ -27,6 +27,7 @@
 #include "periph/uart.h"
 #include "periph_conf.h"
 
+#if UART_0_EN || UART_1_EN || UART2_EN || UART_3_EN
 
 /**
  * @brief Each UART device has to store two callbacks.
@@ -315,3 +316,4 @@ ISR(USART2_RX_vect, ISR_BLOCK)
     }
 }
 #endif /* UART_3_EN */
+#endif /* UART_0_EN || UART_1_EN |UART_2_EN| UART3 */
diff --git a/cpu/mc1322x/maca/maca.c b/cpu/mc1322x/maca/maca.c
index 5af259028a..758204a3d1 100644
--- a/cpu/mc1322x/maca/maca.c
+++ b/cpu/mc1322x/maca/maca.c
@@ -1016,7 +1016,7 @@ uint32_t _maca_init_from_flash ( uint32_t addr ) {
         length = buffer[1] & 0x0000ffff;
 
         while ( i < ( length-4 ) ) {
-            err = nvm_read ( g_nvm_internal_interface_c, type, ( uint8_t * ) buffer, addr+i, 32 );
+            nvm_read ( g_nvm_internal_interface_c, type, ( uint8_t * ) buffer, addr+i, 32 );
             i += 4 * _exec_init_entry ( buffer, _ram_values );
         }
     }
diff --git a/cpu/nrf51822/periph/uart.c b/cpu/nrf51822/periph/uart.c
index 853a4e509a..af86f7bcc6 100644
--- a/cpu/nrf51822/periph/uart.c
+++ b/cpu/nrf51822/periph/uart.c
@@ -30,7 +30,7 @@
 #include "board.h"
 
 /* guard file in case no UART device was specified */
-#if UART_NUMOF
+#if UART_0_EN
 
 /**
  * @brief Each UART device has to store two callbacks.
@@ -241,4 +241,4 @@ void isr_uart0(void)
     }
 }
 
-#endif /* UART_NUMOF */
+#endif /* UART_0_EN */
diff --git a/cpu/stm32f1/periph/uart.c b/cpu/stm32f1/periph/uart.c
index a63ab8d65f..e995af6242 100644
--- a/cpu/stm32f1/periph/uart.c
+++ b/cpu/stm32f1/periph/uart.c
@@ -305,3 +305,4 @@ static inline void irq_handler(uint8_t uartnum, USART_TypeDef *dev)
         thread_yield();
     }
 }
+#endif /* UART_0_EN || UART_1_EN */
diff --git a/examples/rpl_udp/helper.c b/examples/rpl_udp/helper.c
index 475932a019..87d867b002 100644
--- a/examples/rpl_udp/helper.c
+++ b/examples/rpl_udp/helper.c
@@ -136,6 +136,8 @@ void rpl_udp_ignore(int argc, char **argv)
     tcmd.data = &a;
 
     if (argc == 2) {
+        /* cppcheck: a is actually read via tcmd.data */
+        /* cppcheck-suppress unreadVariable */
         a = atoi(argv[1]);
         printf("sending to transceiver (%" PRIkernel_pid "): %u\n", transceiver_pid, (*(uint8_t *)tcmd.data));
         msg_send(&mesg, transceiver_pid);
diff --git a/sys/net/network_layer/sixlowpan/icmp.c b/sys/net/network_layer/sixlowpan/icmp.c
index 5889d8045f..1490f35cb9 100644
--- a/sys/net/network_layer/sixlowpan/icmp.c
+++ b/sys/net/network_layer/sixlowpan/icmp.c
@@ -1518,10 +1518,9 @@ ndp_neighbor_cache_t *ndp_get_ll_address(ipv6_addr_t *ipaddr)
 
 int ndp_addr_is_on_link(ipv6_addr_t *dest_addr)
 {
-    ndp_neighbor_cache_t *nce;
     int if_id = -1;
 
-    if ((nce = ndp_neighbor_cache_search(dest_addr))) {
+    if ((ndp_neighbor_cache_search(dest_addr))) {
 #ifdef DEBUG_ENABLED
         char addr_str[IPV6_MAX_ADDR_STR_LEN];
         DEBUG("INFO: %s is in nbr cache\n", ipv6_addr_to_str(addr_str, IPV6_MAX_ADDR_STR_LEN, dest_addr));
diff --git a/sys/net/network_layer/sixlowpan/ip.c b/sys/net/network_layer/sixlowpan/ip.c
index a61a1d1d5f..060b19462c 100644
--- a/sys/net/network_layer/sixlowpan/ip.c
+++ b/sys/net/network_layer/sixlowpan/ip.c
@@ -680,7 +680,6 @@ void ipv6_net_if_get_best_src_addr(ipv6_addr_t *src, const ipv6_addr_t *dest)
                     uint8_t bmatch = 0;
                     uint8_t tmp = ipv6_get_addr_match(dest, addr->addr_data);
                     if (tmp >= bmatch) {
-                        bmatch = tmp;
                         tmp_addr = addr;
                     }
                 }
diff --git a/sys/net/transport_layer/tcp/tcp.c b/sys/net/transport_layer/tcp/tcp.c
index 65b0bc2e3f..e5b8c38aaa 100644
--- a/sys/net/transport_layer/tcp/tcp.c
+++ b/sys/net/transport_layer/tcp/tcp.c
@@ -683,9 +683,7 @@ void *tcp_packet_handler(void *arg)
             update_tcp_hc_context(true, tcp_socket, tcp_header);
 #endif
             /* Remove reserved bits from tcp flags field */
-            uint8_t tcp_flags = tcp_header->reserved_flags;
-
-            switch (tcp_flags) {
+            switch (tcp_header->reserved_flags) {
                 case TCP_ACK: {
                     /* only ACK Bit set */
                     uint8_t tcp_payload_len = NTOHS(ipv6_header->length) - TCP_HDR_LEN;
diff --git a/sys/transceiver/transceiver.c b/sys/transceiver/transceiver.c
index 1c80dd761c..38bede760c 100644
--- a/sys/transceiver/transceiver.c
+++ b/sys/transceiver/transceiver.c
@@ -811,6 +811,8 @@ static int8_t send_packet(transceiver_type_t t, void *pkt)
  */
 static int32_t set_channel(transceiver_type_t t, void *channel)
 {
+    /* cppcheck: c is read depending on enabled modules */
+    /* cppcheck-suppress unreadVariable */
     uint8_t c = *((uint8_t *)channel);
 
     switch (t) {
@@ -1030,6 +1032,8 @@ static radio_address_t get_address(transceiver_type_t t)
  */
 static radio_address_t set_address(transceiver_type_t t, void *address)
 {
+    /* cppcheck: addr is read depending on enabled modules */
+    /* cppcheck-suppress unreadVariable */
     radio_address_t addr = *((radio_address_t *)address);
 
     switch (t) {