From c0a84367dec88719bbe7d969cc75acd41b8fc64e Mon Sep 17 00:00:00 2001
From: Oskar Weigl <oskar.weigl@gmail.com>
Date: Mon, 10 Jul 2017 19:20:47 -0700
Subject: [PATCH] null terminate usb string before parse

---
 Inc/main.h        | 3 +++
 Src/usbd_cdc_if.c | 4 ++++
 2 files changed, 7 insertions(+)

diff --git a/Inc/main.h b/Inc/main.h
index 811dbfb4..c8d127cb 100644
--- a/Inc/main.h
+++ b/Inc/main.h
@@ -146,6 +146,9 @@
 #define CURRENT_MEAS_PERIOD ((float)(2*TIM_1_8_PERIOD_CLOCKS)/(float)TIM_1_8_CLOCK_HZ)
 #define CURRENT_MEAS_HZ (TIM_1_8_CLOCK_HZ/(2*TIM_1_8_PERIOD_CLOCKS))
 
+#define MACRO_MAX(x, y) (((x) > (y)) ? (x) : (y))
+#define MACRO_MIN(x, y) (((x) < (y)) ? (x) : (y))
+
 /* USER CODE END Private defines */
 
 /**
diff --git a/Src/usbd_cdc_if.c b/Src/usbd_cdc_if.c
index 6b0d57c4..4f06cc58 100644
--- a/Src/usbd_cdc_if.c
+++ b/Src/usbd_cdc_if.c
@@ -265,6 +265,10 @@ static int8_t CDC_Receive_FS (uint8_t* Buf, uint32_t *Len)
   USBD_CDC_SetRxBuffer(&hUsbDeviceFS, &Buf[0]);
   USBD_CDC_ReceivePacket(&hUsbDeviceFS);
 
+  //Append null termination at end of string
+  int null_idx = MACRO_MIN(*Len, APP_RX_DATA_SIZE-1);
+  Buf[null_idx] = 0;
+
   motor_parse_cmd(Buf, *Len);
 
   return (USBD_OK);