diff --git a/include/firmata/firmata.h b/include/firmata/firmata.h
index 72961cb..4ef4bf0 100644
--- a/include/firmata/firmata.h
+++ b/include/firmata/firmata.h
@@ -24,6 +24,8 @@
 
 #pragma once
 
+#include <pthread.h>
+
 #include "uart.h"
 
 #define MODE_INPUT 0x00
@@ -99,6 +101,7 @@ typedef struct s_firmata {
     char firmware[140];
     uint8_t dev_count;
     struct _firmata** devs;
+    pthread_spinlock_t lock;
 } t_firmata;
 
 t_firmata* firmata_new(const char* name);
diff --git a/src/firmata/firmata.c b/src/firmata/firmata.c
index 67355b5..68068f3 100644
--- a/src/firmata/firmata.c
+++ b/src/firmata/firmata.c
@@ -39,6 +39,13 @@ firmata_new(const char* name)
         return NULL;
     }
 
+    int ret = pthread_spin_init(&res->lock, PTHREAD_PROCESS_SHARED);
+    if (ret != 0) {
+        syslog(LOG_ERR, "firmata; could not init locking");
+        free(res);
+        return NULL;
+    }
+
     res->uart = mraa_uart_init_raw(name);
     if (res->uart == NULL) {
         syslog(LOG_ERR, "firmata: UART failed to setup");
@@ -133,7 +140,9 @@ firmata_endParse(t_firmata* firmata)
         int analog_val = firmata->parse_buff[1] | (firmata->parse_buff[2] << 7);
         for (pin = 0; pin < 128; pin++) {
             if (firmata->pins[pin].analog_channel == analog_ch) {
+                if (pthread_spin_lock(&firmata->lock) != 0) return;
                 firmata->pins[pin].value = analog_val;
+                if (pthread_spin_unlock(&firmata->lock) != 0) syslog(LOG_ERR, "firmata: Fatal spinlock deadlock");
                 return;
             }
         }
@@ -147,7 +156,9 @@ firmata_endParse(t_firmata* firmata)
         for (mask = 1; mask & 0xFF; mask <<= 1, pin++) {
             if (firmata->pins[pin].mode == MODE_INPUT) {
                 uint32_t val = (port_val & mask) ? 1 : 0;
+                if (pthread_spin_lock(&firmata->lock)) return;
                 firmata->pins[pin].value = val;
+                if (pthread_spin_unlock(&firmata->lock) != 0) syslog(LOG_ERR, "firmata: Fatal spinlock deadlock");
             }
         }
         return;
@@ -240,10 +251,12 @@ firmata_endParse(t_firmata* firmata)
             int reg = (firmata->parse_buff[4] & 0x7f) | ((firmata->parse_buff[5] & 0x7f) << 7);
             int i = 6;
             int ii = 0;
+            if (pthread_spin_lock(&firmata->lock) != 0) syslog(LOG_ERR, "firmata: Fatal spinlock deadlock, skipping i2c msg");
             for (; ii < (firmata->parse_count - 7) / 2; ii++) {
                 firmata->i2cmsg[addr][reg+ii] = (firmata->parse_buff[i] & 0x7f) | ((firmata->parse_buff[i+1] & 0x7f) << 7);
                 i = i+2;
             }
+            if (pthread_spin_unlock(&firmata->lock) != 0) syslog(LOG_ERR, "firmata: Fatal spinlock deadlock");
         } else {
             if (firmata->devs != NULL) {
                 struct _firmata* devs = firmata->devs[0];
diff --git a/src/firmata/firmata_mraa.c b/src/firmata/firmata_mraa.c
index f515972..e370824 100644
--- a/src/firmata/firmata_mraa.c
+++ b/src/firmata/firmata_mraa.c
@@ -84,6 +84,7 @@ mraa_result_t
 mraa_firmata_close(mraa_firmata_context dev)
 {
     mraa_firmata_response_stop(dev);
+    pthread_spin_destroy(&firmata_dev->lock);
     free(dev);
     return MRAA_SUCCESS;
 }
@@ -182,11 +183,17 @@ static mraa_result_t
 mraa_firmata_i2c_wait(int addr, int reg)
 {
     int i = 0;
-    for (; firmata_dev->i2cmsg[addr][reg] == -1; i++) {
+    if (pthread_spin_lock(&firmata_dev->lock) != 0) return MRAA_ERROR_UNSPECIFIED;
+    int res = firmata_dev->i2cmsg[addr][reg];
+    if (pthread_spin_unlock(&firmata_dev->lock) != 0) return MRAA_ERROR_UNSPECIFIED;
+    for (; res == -1; i++) {
         if (i > 50) {
             return MRAA_ERROR_UNSPECIFIED;
         }
         usleep(500);
+        if (pthread_spin_lock(&firmata_dev->lock) != 0) return MRAA_ERROR_UNSPECIFIED;
+        res = firmata_dev->i2cmsg[addr][reg];
+        if (pthread_spin_unlock(&firmata_dev->lock) != 0) return MRAA_ERROR_UNSPECIFIED;
     }
     return MRAA_SUCCESS;
 }
@@ -345,7 +352,10 @@ mraa_firmata_aio_read(mraa_aio_context dev)
 {
     // careful, whilst you need to enable '0' for A0 you then need to read 14
     // in t_firmata because well that makes sense doesn't it...
-    return (int) firmata_dev->pins[dev->channel].value;
+    if (pthread_spin_lock(&firmata_dev->lock) != 0) return -1;
+    int ret = (int) firmata_dev->pins[dev->channel].value;
+    if (pthread_spin_unlock(&firmata_dev->lock) != 0) return -1;
+    return ret;
 }
 
 static mraa_result_t
@@ -380,7 +390,10 @@ mraa_firmata_gpio_mode_replace(mraa_gpio_context dev, mraa_gpio_mode_t mode)
 static int
 mraa_firmata_gpio_read_replace(mraa_gpio_context dev)
 {
-    return firmata_dev->pins[dev->pin].value;
+    if (pthread_spin_lock(&firmata_dev->lock) != 0) return -1;
+    int res = firmata_dev->pins[dev->pin].value;
+    if (pthread_spin_unlock(&firmata_dev->lock) != 0) return -1;
+    return res;
 }
 
 static mraa_result_t