Get ding working with breadboard and limit sendto() to 32 bytes.

6 files changed, 55 insertions, 37 deletions

diff --git a/Ding.Makefile b/Ding.Makefile
index 2f31bc2..6d6801a 100644
--- a/Ding.Makefile
+++ b/Ding.Makefile
@@ -2,7 +2,7 @@ CC = avr-gcc
 MCU = atmega328p
 TARGET = ding
 
-SRC = ding.c uart.c nrfm.c
+SRC = ding.c uart.c nrfm.c util.c
 OBJ = $(SRC:.c=.o)
 
 CFLAGS = -std=gnu99
diff --git a/Dong.Makefile b/Dong.Makefile
index 4dcb942..bf03e11 100644
--- a/Dong.Makefile
+++ b/Dong.Makefile
@@ -2,7 +2,7 @@ CC = avr-gcc
 MCU = atmega328p
 TARGET = dong
 
-SRC = dong.c uart.c nrfm.c
+SRC = dong.c uart.c nrfm.c util.c
 OBJ = $(SRC:.c=.o)
 
 CFLAGS = -std=gnu99
diff --git a/ding.c b/ding.c
index 5950ddc..34ff38c 100644
--- a/ding.c
+++ b/ding.c
@@ -1,9 +1,12 @@
 #include <stdint.h>
 #include <string.h>
+
+#include <avr/wdt.h>
 #include <util/delay.h>
 
 #include "nrfm.h"
 #include "uart.h"
+#include "util.h"
 
 int main(void)
 {
@@ -13,15 +16,16 @@ int main(void)
 	uint8_t rxaddr[ADDRLEN] = { 194, 178, 82 };
 	uint8_t txaddr[ADDRLEN] = { 194, 178, 83 };
 
+	wdt_init();
 	uart_init();
 	radio_init(rxaddr);
 	radio_print_config();
 
 	for (;;) {
 		radio_sendto(txaddr, s, slen);
+		wdt_reset();
 		_delay_ms(2000);
 	}
 
-
 	return 0;
 }
diff --git a/nrfm.c b/nrfm.c
index 885155a..7ec45df 100644
--- a/nrfm.c
+++ b/nrfm.c
@@ -224,12 +224,12 @@ void radio_init(const uint8_t rxaddr[ADDRLEN])
 void radio_sendto(const uint8_t addr[ADDRLEN], const char *msg, uint8_t n)
 {
 	char s[4];
-	uint8_t cfg;
-	int i, j, jmax;
-	uint8_t rv, maxrt, txds;
+	int i, imax;
+	uint8_t cfg, rv, maxrt, txds;
 
 	disable_chip();
 
+	imax = n < MAXPDLEN ? n : MAXPDLEN;
 	cfg = read_reg(0x00);
 
 	tx_mode();
@@ -246,36 +246,32 @@ void radio_sendto(const uint8_t addr[ADDRLEN], const char *msg, uint8_t n)
 	uart_write(".");
 	uart_write_line(itoa(addr[2], s, 10));
 
-	for (i = 0; i < n; i += MAXPDLEN) {
-		SPI_PORT &= ~(1 << SPI_SS);
-		SPDR = 0b10100000;
+	SPI_PORT &= ~(1 << SPI_SS);
+	SPDR = 0b10100000;
+	while (!(SPSR & (1 << SPIF)))
+		;
+	for (i = 0; i < imax; i++) {
+		SPDR = msg[i];
 		while (!(SPSR & (1 << SPIF)))
-			;
-		jmax = i + MAXPDLEN;
-		for (j = i; j < jmax; j++) {
-			SPDR = msg[j];
-			while (!(SPSR & (1 << SPIF)))
-				;
-		}
-		SPI_PORT |= (1 << SPI_SS);
-
-		enable_chip();
-		_delay_us(12);
-		disable_chip();
-
-		txds = 0, maxrt = 0;
-		do {
-			rv = read_reg(0x07);	
-			txds = rv & (1 << 5);
-			maxrt = rv & (1 << 4);
-		} while (txds == 0 && maxrt == 0);
-
-		if (txds)
-			uart_write_line("DEBUG: packet sent");
-		else if (maxrt) {
-			uart_write_line("ERROR: sendto() failed: MAX_RT");
-			break;
-		}
+		;
+	}
+	SPI_PORT |= (1 << SPI_SS);
+
+	enable_chip();
+	_delay_us(12);
+	disable_chip();
+
+	txds = 0, maxrt = 0;
+	do {
+		rv = read_reg(0x07);	
+		txds = rv & (1 << 5);
+		maxrt = rv & (1 << 4);
+	} while (txds == 0 && maxrt == 0);
+
+	if (txds)
+		uart_write_line("DEBUG: packet sent");
+	else if (maxrt) {
+		uart_write_line("ERROR: sendto() failed: MAX_RT");
 	}
 
 	write_reg(0x00, cfg);
@@ -291,7 +287,7 @@ void radio_listen(void)
 uint8_t radio_recv(char *buf, uint8_t n)
 {
 	char s[3];
-	int readlen, pdlen;
+	int readlen, pdlen, readmax;
 
 	pdlen = 0;
 	disable_chip();
@@ -315,11 +311,13 @@ uint8_t radio_recv(char *buf, uint8_t n)
 		return 0;
 	}
 
+	readmax = (n - 1) < pdlen ? (n - 1) : pdlen;
+
 	SPI_PORT &= ~(1 << SPI_SS);
 	SPDR = 0b01100001;
 	while (!(SPSR & (1 << SPIF)))
 		;
-	for (readlen = 0; readlen < pdlen; readlen++) {
+	for (readlen = 0; readlen <= readmax; readlen++) {
 		SPDR = NOP;
 		while (!(SPSR & (1 << SPIF)))
 			;
diff --git a/util.c b/util.c
new file mode 100644
index 0000000..ddfdf04
--- /dev/null
+++ b/util.c
@@ -0,0 +1,10 @@
+#include <avr/wdt.h>
+
+#include "util.h"
+
+void wdt_init(void)
+{
+	wdt_reset();
+	WDTCSR |= (1 << WDCE) | (1 << WDE);
+	WDTCSR = (1 << WDE) | (1 << WDP3) | (1 << WDP0);
+}
diff --git a/util.h b/util.h
new file mode 100644
index 0000000..75cd9ad
--- /dev/null
+++ b/util.h
@@ -0,0 +1,6 @@
+#ifndef MY_UTIL_H
+#define MY_UTIL_H
+
+void wdt_init(void);
+
+#endif