MODBUS: Debugging and hooks

diff --git a/lib/modbus.c b/lib/modbus.c
index c6336460d307d1a8fe814e77b3159409ddaeb113..41757d310e66af3e2d56db061213fa3d4587caa9 100644 (file)
--- a/lib/modbus.c
+++ b/lib/modbus.c
@@ -66,6 +66,14 @@
 #endif
 #endif
 
+// Debugging
+// #define MODBUS_DEBUG
+
+#ifdef MODBUS_DEBUG
+#define DEBUG debug_printf
+#else
+#define DEBUG(xxx, ...) do { } while (0)
+#endif
 /*** State ***/
 
 enum mb_state {
@@ -101,6 +109,7 @@ static void rx_init(void)
        rx_bad = 0;
        usart_set_mode(MODBUS_USART, USART_MODE_RX);
        usart_enable_rx_interrupt(MODBUS_USART);
+       modbus_ready_hook();
 }
 
 static void rx_done(void)
@@ -127,6 +136,8 @@ static void tx_done(void)
 
 void modbus_init(void)
 {
+       DEBUG("MODBUS: Init\n");
+
        timer_set_prescaler(MODBUS_TIMER, CPU_CLOCK_MHZ-1);     // 1 tick = 1 μs
        timer_set_mode(MODBUS_TIMER, TIM_CR1_CKD_CK_INT, TIM_CR1_CMS_EDGE, TIM_CR1_DIR_DOWN);
        timer_update_on_overflow(MODBUS_TIMER);
@@ -159,6 +170,8 @@ void MODBUS_USART_ISR(void)
                        if (status & (USART_SR_FE | USART_SR_ORE | USART_SR_NE)) {
                                rx_bad = 1;
                        } else if (rx_size < MODBUS_RX_BUFSIZE) {
+                               if (!rx_size)
+                                       modbus_frame_start_hook();
                                rx_buf[rx_size++] = ch;
                        } else {
                                // Frame too long
@@ -212,9 +225,12 @@ void modbus_loop(void)
                return;
        }
 
+       DEBUG("MODBUS: < dest=%02x func=%02x len=%u\n", rx_buf[0], rx_buf[1], rx_size);
+
        if (rx_buf[0] == MODBUS_OUR_ADDRESS) {
                // Frame addressed to us: process and reply
                process_frame();
+               DEBUG("MODBUS: > status=%02x len=%u\n", tx_buf[1], tx_size);
                tx_init();
        } else if (rx_buf[0] == 0x00) {
                // Broadcast frame: process, but do not reply
@@ -305,11 +321,13 @@ static bool check_frame(void)
 {
        if (rx_bad) {
                // FIXME: Error counters?
+               DEBUG("MODBUS: RX bad\n");
                return false;
        }
        
        if (rx_size < 4) {
                // FIXME: Error counters?
+               DEBUG("MODBUS: RX undersize\n");
                return false;
        }
 
@@ -317,6 +335,7 @@ static bool check_frame(void)
        u16 rx_crc = (rx_buf[rx_size-2] << 8) | rx_buf[rx_size-1];
        if (crc != rx_crc) {
                // FIXME: Error counters?
+               DEBUG("MODBUS: Bad CRC\n");
                return false;
        }
 

diff --git a/lib/modbus.h b/lib/modbus.h
index 913a149c350ae62f1d67167150388708f71dbe8f..cb926e39fc23134544bf7030fa9d11346255ab93 100644 (file)
--- a/lib/modbus.h
+++ b/lib/modbus.h
@@ -26,6 +26,9 @@ bool modbus_check_holding_register(u16 addr);
 u16 modbus_get_holding_register(u16 addr);
 void modbus_set_holding_register(u16 addr, u16 value);
 
+void modbus_ready_hook(void);
+void modbus_frame_start_hook(void);
+
 enum modbus_id_object {
        MODBUS_ID_VENDOR_NAME,          // first three must be always defined
        MODBUS_ID_PRODUCT_CODE,