diff --git a/consumerir/consumerir.c b/consumerir/consumerir.c
index a4bfed7..5192462 100644
--- a/consumerir/consumerir.c
+++ b/consumerir/consumerir.c
@@ -15,6 +15,9 @@
  */
 #define LOG_TAG "ConsumerIrHal"
 
+#include <stdlib.h>
+#include <malloc.h>
+#include <stdbool.h>
 #include <errno.h>
 #include <string.h>
 #include <unistd.h>
@@ -34,18 +37,62 @@ static const consumerir_freq_range_t consumerir_freqs[] = {
     {.min = 56000, .max = 56000},
 };
 
+static bool
+try_append_number(char *buffer, int *len, int size, int number)
+{
+    int stored;
+
+    stored = snprintf(&buffer[*len], size - *len, "%d,", number);
+
+    if (stored < 0 || stored >= size - *len) {
+        return false;
+    }
+
+    *len += stored;
+    return true;
+}
+
+static bool
+grow_buffer(char **buffer, int *size)
+{
+    char *new_buffer;
+
+    *size *= 2;
+    if ((new_buffer = realloc(*buffer, *size)) == NULL) {
+        return false;
+    }
+    *buffer = new_buffer;
+    return true;
+}
+
+static bool
+append_number(char **buffer, int *len, int *size, int number)
+{
+    if (! try_append_number(*buffer, len, *size, number)) {
+        if (! grow_buffer(buffer, size)) return false;
+        return try_append_number(*buffer, len, *size, number);
+    } else {
+        return true;
+    }
+}
+
 int fd = 0;
 static int consumerir_transmit(struct consumerir_device *dev,
    int carrier_freq, int pattern[], int pattern_len)
 {
-    int strlen;
+    int buffer_len = 0;
+    int buffer_size = 128;
     int i;
-    char buffer[2048];
+    char *buffer;
 
-    memset(buffer, 0, 2048);
+    if ((buffer = malloc(buffer_size)) == NULL) {
+        return -ENOMEM;
+    }
 
     /* write the header */
-    strlen = sprintf(buffer, "%d,", carrier_freq);
+    if (! append_number(&buffer, &buffer_len, &buffer_size, carrier_freq)) {
+        goto error;
+    }
 
     /* calculate factor of conversion from microseconds to pulses */
     float factor = 1000000 / carrier_freq;
@@ -53,14 +100,21 @@ static int consumerir_transmit(struct consumerir_device *dev,
     /* write out the timing pattern */
     for (i = 0; i < pattern_len; i++)
     {
-        strlen += sprintf(buffer + strlen, "%d,", (int) (pattern[i]/factor));
+        if (! append_number(&buffer, &buffer_len, &buffer_size, (int) (pattern[i]/factor))) {
+            goto error;
+        }
     }
 
-    buffer[strlen - 1] = 0;
+    buffer[buffer_len - 1] = 0;
+    write(fd, buffer, buffer_len - 1);
 
-    write(fd, buffer, strlen - 1);
+    free(buffer);
 
     return 0;
+
+error:
+    free(buffer);
+    return -ENOMEM;
 }
 
 static int consumerir_get_num_carrier_freqs(struct consumerir_device *dev)