+/* 16 channels * 32 samples */
+#define CONV_BATCH_SIZE (2*32)
+/* one packet + one partial conversion:
+ * worst case is only one active channel converted to 2 bytes per sample, with
+ * 8*16384 samples per packet
+ */
+#define CONV_BUFFER_SIZE (2*8*16384 + CONV_BATCH_SIZE)
+