# HG changeset patch
# User Ethan Zonca <ez@ethanzonca.com>
# Date 2015-03-29 20:58:14
# Node ID b5b1fc08b294390d4cd0b38ba54d1d7dda9cd3d3
# Parent  cfa4fd71c861a0c5b5bc7560d49f8d42f1896e33

Added virtual serial port periodic transmission of temperature. Trying out bootloader code, but still doesn't work.

diff --git a/config.h b/config.h
--- a/config.h
+++ b/config.h
@@ -1,7 +1,7 @@
 #ifndef CONFIG_H
 #define CONFIG_H
 
-
+#define VCP_TX_FREQ 1000
 #define SSR_PERIOD 200
 
 #define LED_POWER GPIOF,GPIO_PIN_0
diff --git a/flash.sh b/flash.sh
--- a/flash.sh
+++ b/flash.sh
@@ -2,3 +2,7 @@
 cd build
 st-flash write main.bin 0x8000000
 cd ..
+
+
+# USB DFU:
+# sudo  dfu-util -a 0 -d 0483:df11 -s 0x08000000:leave -D build/main.bin
diff --git a/main.c b/main.c
--- a/main.c
+++ b/main.c
@@ -231,20 +231,6 @@ void update_temp() {
             temp = temp_pre * signint;
         }
     }
-
-    // Print temp to cdc
-/*
-    CDC_Transmit_FS("Temp: ", 6);
-    char tempstr[6];
-    zitoa(temp, tempstr);
-    CDC_Transmit_FS(tempstr, sizeof(tempstr));
-
-    CDC_Transmit_FS("\r\n", 2);
-    CDC_Transmit_FS("\r\n", 2);
-    CDC_Transmit_FS("\r\n", 2);
-    CDC_Transmit_FS("\r\n", 2);
-    CDC_Transmit_FS("\r\n", 2);
-*/
 }
 
 
@@ -301,6 +287,7 @@ int16_t update_pid(uint16_t k_p, uint16_
 
 
 uint32_t last_ssr_on = 0;
+uint32_t last_vcp_tx = 0;
 uint32_t last_led = 0;
 int32_t setpoint = 0;
 int16_t ssr_output = 0; // Duty cycle of ssr, 0 to SSR_PERIOD 
@@ -352,6 +339,18 @@ void process()
     {
         HAL_GPIO_WritePin(SSR_PIN, 0);
     }
+
+    if(ticks - last_vcp_tx > VCP_TX_FREQ)
+    {
+        // Print temp to cdc
+        char tempstr[6];
+        itoa_fp(temp, temp_frac, tempstr);
+
+        while(CDC_Transmit_FS(tempstr, sizeof(tempstr)) == USBD_BUSY);
+        while(CDC_Transmit_FS("\r\n", 2) == USBD_BUSY);
+
+        last_vcp_tx = ticks;
+    }
 }
 
 
@@ -536,7 +535,13 @@ void machine()
                         ssd1306_clearscreen();
                         ssd1306_DrawString("Entering Bootloader", 1, 0);
                         ssd1306_DrawString("(hopefully)", 2, 0);
-                        HAL_Delay(1000);
+                        //HAL_Delay(1000);
+                        HAL_RCC_DeInit();
+                        SysTick->CTRL = 0;
+                        SysTick->LOAD = 0;
+                        SysTick->VAL = 0;
+                        __set_PRIMASK(1);
+                        __set_MSP(0x200010000);
                         *((unsigned long *)0x200017F0) = 0xDEADBEEF; // 6KB STM32F042
                         NVIC_SystemReset();
 
diff --git a/startup_stm32f042x6.s b/startup_stm32f042x6.s
--- a/startup_stm32f042x6.s
+++ b/startup_stm32f042x6.s
@@ -84,15 +84,33 @@ Reset_Handler:
 
 /* Boot into bootloader */
 Reboot_Loader:
-  ldr r0, =0x1FFFF6A6 /* Address of bootloader on f042 from CD00167594 pg 15 table 3 */
-  /* This replaces ldr sp, [r0, #0] which doesn't work on m0 */
-  // Set stack pointer
-  ldr r1, [r0, #0]
-  mov sp, r1
+  LDR     R0, =0x40021018 // RCC_APB2ENR (+0x18)
+  LDR     R1, =0x00000001 // ENABLE SYSCFG CLOCK
+  STR     R1, [R0, #0]
+  LDR     R0, =0x40010000 // SYSCFG_CFGR1 (+0x00)
+  LDR     R1, =0x00000001 // MAP ROM AT ZERO
+  STR     R1, [R0, #0]
+  //                LDR     R0, =0x1FFFEC00 ; ROM BASE (STM32F03x)
+  LDR     R0, =0x1FFFC400 // ROM BASE (STM32F04x)
+  //                LDR     R0, =0x1FFFEC00 ; ROM BASE (STM32F05x)
+  //                LDR     R0, =0x1FFFC800 ; ROM BASE (STM32F07x)
+  //                LDR     R0, =0x1FFFD800 ; ROM BASE (STM32F09x)
+  LDR     R1, [R0, #0]    // SP @ +0
+  MOV     SP, R1
+  LDR     R0, [R0, #4]    // PC @ +4
+  BX      R0
+
+
+  // On reset, SP=value at address 0x0
+//  ldr r0, =0x00000000
+//  ldr r0, [r0, #0]
+//  mov sp, r0
+
+//  ldr r0, =0x1FFFC800 /* Address of bootloader on f042 from CD00167594 pg 15 table 3 */
 
   // Branch to bootloader
-  ldr r0, [r0, #4]
-  bx r0
+//  ldr r0, [r0, #4]
+//  bx r0
 
 
 CopyDataInit:
diff --git a/usbd_cdc_if.c b/usbd_cdc_if.c
--- a/usbd_cdc_if.c
+++ b/usbd_cdc_if.c
@@ -290,10 +290,13 @@ uint8_t CDC_Transmit_FS(uint8_t* Buf, ui
     /* USER CODE BEGIN 8 */
     uint16_t i;
 
+
+    // Zero out user TX buffer (EMZ FIXME: why bother?)
     for (i=0; i < sizeof(UserTxBufferFS); i++) {
 	UserTxBufferFS[i] = 0;
     }
 
+    // Copy input buff to user TX buffer
     for (i=0; i < Len; i++) {
 	UserTxBufferFS[i] = Buf[i];
     }