diff --git a/SerialPorts.c b/SerialPorts.c
index 0aa603a..789278e 100644
--- a/SerialPorts.c
+++ b/SerialPorts.c
@@ -130,7 +130,7 @@ static void vSerialPort_InitUSART2(tSerialPortFlagchip *env) {
 tSerialPorts SERIAL_PORTS;
 
 
-uint8_t buf_USART1_TRANSMITTED[256];
+uint8_t buf_USART1_TRANSMITTED[32];
 ALIGN(256) uint8_t buf_USART1_DMA[128];
 
 
@@ -227,7 +227,7 @@ static void vSerialPort_InitUSART1(tSerialPortFlagchip *env) {
             DMA6_IRQn, // IRQ_DMA_CHANNEL_PRIORITY
 
 
-            1024,
+            256,
             0,
 
             DMA_USART1_TransferCompleteCallbackRx,