commit 1b6fbd08ec9a085268be1b06a95a3a6d6338b9d3
author Brian Silverman <brians> Thu Dec 12 18:08:47 2013 -0800
committer Brian Silverman <brians> Thu Dec 12 18:08:47 2013 -0800
tree 5b0ad588302ed2ce9a4dd50280823dd352b35a84
parent df49fe36f90c219979c933207fe0362c6cff73e4

(theoretically) got encoders working

Everything up to sending all 8 encoder values should work now (including
the packet format + header information, bootloader (fixed some bugs in
the UART code for that), etc).

bbb_cape/src/cape/fill_packet.c

diff --git a/bbb_cape/src/cape/fill_packet.c b/bbb_cape/src/cape/fill_packet.c
index e8516a9..537c527 100644
--- a/bbb_cape/src/cape/fill_packet.c
+++ b/bbb_cape/src/cape/fill_packet.c
@@ -7,10 +7,38 @@
 #include "cape/uart_dma.h"
 #include "cape/uart_common.h"
 #include "cape/cows.h"
+#include "cape/encoder.h"
+#include "cape/crc.h"
+#include "cape/bootloader_handoff.h"
+
+#define TIMESTAMP_TIM TIM6
+#define RCC_APB1ENR_TIMESTAMP_TIMEN RCC_APB1ENR_TIM6EN
 
 static uint8_t buffer1[DATA_STRUCT_SEND_SIZE] __attribute__((aligned(4)));
 static uint8_t buffer2[DATA_STRUCT_SEND_SIZE] __attribute__((aligned(4)));
 
+static uint32_t flash_checksum;
+// These aren't really integers; they're (4-byte) variables whose addresses mark
+// various locations.
+extern uint8_t __etext, __data_start__, __data_end__;
+
+static inline void do_fill_packet(struct DataStruct *packet) {
+  static uint64_t timestamp = 0;
+  counter_update_u64_u16(&timestamp, TIMESTAMP_TIM->CNT);
+  packet->timestamp = timestamp;
+
+  packet->flash_checksum = flash_checksum;
+
+  packet->main.encoders[0] = encoder_read(0);
+  packet->main.encoders[1] = encoder_read(1);
+  packet->main.encoders[2] = encoder_read(2);
+  packet->main.encoders[3] = encoder_read(3);
+  packet->main.encoders[4] = encoder_read(4);
+  packet->main.encoders[5] = encoder_read(5);
+  packet->main.encoders[6] = encoder_read(6);
+  packet->main.encoders[7] = encoder_read(7);
+}
+
 // Fills the new packet with data.
 void uart_dma_callback(uint8_t *buffer) {
   struct {
@@ -22,23 +50,28 @@
                 The_size_of_the_data_is_wrong);
   struct DataStruct *packet = &data.packet;
 
-  CRC->CR = 1;  // reset it
-  uint32_t *p1;
-  memcpy(&p1, &packet, sizeof(void *));
-  {
-    uint32_t *restrict p = p1;
-    for (; p < (uint32_t *)(packet + 1); ++p) {
-      CRC->DR = *p;
-    }
-  }
-  data.checksum = CRC->DR;
+  do_fill_packet(packet);
+
+  uint32_t *p;
+  memcpy(&p, &packet, sizeof(void *));
+  data.checksum = crc_calculate(p, sizeof(*packet) / 4);
 
   memset(buffer, 0, 4);
   cows_stuff(&data, sizeof(data), buffer + 4);
 }
 
 void fill_packet_start(void) {
-  RCC->AHB1ENR |= RCC_AHB1ENR_CRCEN;
+  RCC->APB1ENR |= RCC_APB1ENR_TIMESTAMP_TIMEN;
+  TIMESTAMP_TIM->CR1 = TIM_CR1_UDIS;
+  TIMESTAMP_TIM->EGR = TIM_EGR_UG;
+  TIMESTAMP_TIM->CR1 |= TIM_CR1_CEN;
+
+  crc_init();
+  encoder_init();
+
+  uint8_t *flash_end = &__etext + (&__data_start__ - &__data_end__) + 8;
+  flash_checksum = crc_calculate((void *)MAIN_FLASH_START,
+                                 (size_t)(flash_end - MAIN_FLASH_START) / 4);
 
   uart_common_configure(3000000);
   uart_dma_configure(DATA_STRUCT_SEND_SIZE, buffer1, buffer2);