From 424310d957cb04bfacba9c711ee7f074fd41f962 Mon Sep 17 00:00:00 2001
From: jaseg <git@jaseg.de>
Date: Fri, 27 Nov 2020 13:38:56 +0100
Subject: demo fw WIP

---
 prototype/fw/src/main.c | 131 ++++++++++++++++++++++++++++++++++++++----------
 1 file changed, 105 insertions(+), 26 deletions(-)

(limited to 'prototype/fw/src/main.c')

diff --git a/prototype/fw/src/main.c b/prototype/fw/src/main.c
index de920eb..fb3c302 100644
--- a/prototype/fw/src/main.c
+++ b/prototype/fw/src/main.c
@@ -1,49 +1,128 @@
 
 #include <global.h>
 
+#include "microcobs.h"
+#include "crc32.h"
+
+struct __attribute__((packed)) ll_pkt_trailer {
+    uint32_t crc32;
+};
+
+struct __attribute__((packed)) req_pkt {
+    uint32_t req_seq;
+    struct ll_pkt_trailer trailer;
+};
+
+struct __attribute__((packed)) res_pkt {
+    uint32_t req_seq;
+    uint32_t res_seq;
+    struct ll_pkt_trailer trailer;
+};
+
+struct tx_state {
+    uint8_t *tx_char;
+    int remaining_bytes;
+};
+
+static crc32_t pkt_crc(void *pkt, struct ll_pkt_trailer *trailer);
+crc32_t pkt_crc(void *pkt, struct ll_pkt_trailer *trailer) {
+    crc32_t crc = crc32_reset();
+    for (uint8_t *in = (uint8_t *)pkt; in < (uint8_t *)trailer; in++) {
+        crc = crc32_update(crc, *in);
+    }
+    return crc32_finalize(crc);
+}
+
+static void packetize(void *pkt, struct ll_pkt_trailer *trailer);
+void packetize(void *pkt, struct ll_pkt_trailer *trailer) {
+    trailer->crc32 = pkt_crc(pkt, trailer);
+}
+
 int main(void) {
 
     RCC->AHBENR |= RCC_AHBENR_GPIOAEN;
     RCC->APB2ENR |= RCC_APB2ENR_USART1EN;
 
-    GPIOA->MODER |= (2 << GPIO_MODER_MODER9_Pos);
-    GPIOA->AFR[1] = (7 << (9-8)*4);
+    GPIOA->MODER |= (2 << GPIO_MODER_MODER9_Pos) | (2 << GPIO_MODER_MODER10_Pos);
+    GPIOA->AFR[1] = (7 << (9-8)*4) | (7 << (10-8)*4);
 
     SystemCoreClockUpdate();
     int apb2_clock = SystemCoreClock / APB2_PRESC;
     
     int baudrate = 115200;
 
-    USART1->CR1 = USART_CR1_MME | USART_CR1_TE;
+    USART1->CR1 = USART_CR1_TE | USART_CR1_RE;
     USART1->BRR = (apb2_clock + baudrate/2) / baudrate;
+    USART1->CR1 |= USART_CR2_RXINV;
     USART1->CR1 |= USART_CR1_UE;
 
-    char s[12] = {
-        '0', '0', '0', '0', '0',
-        ' ', 'T', 'E', 'S', 'T',
-        '\n', '\0'};
-    int line = 0;
-    char *c = s;
-    USART1->TDR = *(c++); /* Kick off transmission */
+    int req_seq = 0;
+    int res_seq = 0;
+    struct req_pkt req_buf = { 0 };
+    struct tx_state tx_st = { 0 };
+    struct res_pkt res_buf = { 0 };
+    uint8_t rx_buf[512];
+    uint8_t tx_buf[512];
+    size_t rx_char = 0;
+    unsigned int rx_overrun = 0;
+    unsigned int rx_cobs_error = 0;
+    unsigned int rx_framing_error = 0;
+    unsigned int rx_crc_error = 0;
+
+    USART1->TDR = 0; /* Kick off transmission */
     while (23) {
-        if (USART1->ISR & USART_ISR_TXE) {
+        if (tx_st.remaining_bytes == 0) {
+            res_buf.req_seq = req_seq;
+            res_buf.res_seq = res_seq;
+            res_seq += 1;
+            packetize(&res_buf, &res_buf.trailer);
+            tx_st.tx_char = tx_buf;
+            tx_st.remaining_bytes = cobs_encode((uint8_t *)&res_buf, sizeof(res_buf), tx_buf, sizeof(tx_buf));;
+        }
+
+        if (USART1->ISR & USART_ISR_TXE && tx_st.remaining_bytes > 0) {
             for (int i=0; i<100; i++)
                 asm volatile ("nop");
-            USART1->TDR = *(c++);
-            if (!*c) {
-                c = s;
-                line++;
-                int tmp = line;
-                tmp %= 100000;
-                s[0] = '0' + tmp/10000;
-                tmp %= 10000;
-                s[1] = '0' + tmp/1000;
-                tmp %= 1000;
-                s[2] = '0' + tmp/100;
-                tmp %= 100;
-                s[3] = '0' + tmp/10;
-                tmp %= 10;
-                s[4] = '0' + tmp;
+            USART1->TDR = *(tx_st.tx_char);
+            tx_st.tx_char += 1;
+            tx_st.remaining_bytes -= 1;
+        }
+
+        if (USART1->ISR & USART_ISR_ORE)
+            USART1->ICR = USART_ICR_ORECF;
+
+        if (USART1->ISR & USART_ISR_NE)
+            USART1->ICR = USART_ICR_NCF;
+
+        if (USART1->ISR & USART_ISR_FE)
+            USART1->ICR = USART_ICR_FECF;
+
+        if (USART1->ISR & USART_ISR_RXNE) {
+            uint8_t c = USART1->RDR;
+            if (!c) {
+                int rc = cobs_decode(rx_buf, rx_char, (uint8_t *)&req_buf, sizeof(req_buf));
+                if (rc < 0) {
+                    rx_cobs_error += 1;
+                } else {
+                    if (rc == sizeof(req_buf)) {
+                        crc32_t check_crc = pkt_crc(&req_buf, &req_buf.trailer);
+                        if (check_crc != req_buf.trailer.crc32) {
+                            rx_crc_error += 1;
+                        } else {
+                            req_seq = req_buf.req_seq;
+                        }
+                    } else {
+                        rx_framing_error += 1;
+                    }
+                }
+                rx_char = 0;
+            } else {
+                if (rx_char < sizeof(rx_buf)) {
+                    rx_buf[rx_char] = c;
+                    rx_char += 1;
+                } else {
+                    rx_overrun += 1;
+                }
             }
         }
     }
-- 
cgit