From e34917da814c2cdb3710553d479df0aed3979e28 Mon Sep 17 00:00:00 2001
From: Sadeep Madurange <sadeep@asciimx.com>
Date: Sun, 6 Apr 2025 12:01:05 +0800
Subject: Recv data reliably, but PDLEN value is wrong.

---
 nrfm.c | 28 ++++++++++++++++------------
 recv.c | 16 +++++++++-------
 2 files changed, 25 insertions(+), 19 deletions(-)

diff --git a/nrfm.c b/nrfm.c
index 6f27a82..afbb1d9 100644
--- a/nrfm.c
+++ b/nrfm.c
@@ -212,7 +212,7 @@ void radio_init(const uint8_t rxaddr[ADDRLEN])
 	write_reg(0x05, 0b01110011);  /* use 2.515GHz channel */
 	write_reg(0x06, 0b00001110);  /* set data rate to 1Mbps */
 	write_reg(0x1D, 0b00000100);  /* enable dynamic payload length */
-	write_reg(0x1C, 0b00000001);  /* enable dynamic payload length for pipe 0 */
+	write_reg(0x1C, 0b00111111);  /* enable dynamic payload length for all pipes */
 
 	reset_irqs();
 	setaddr(0x0A, rxaddr);
@@ -287,24 +287,28 @@ void radio_listen(void)
 
 uint8_t radio_recv(char *buf, uint8_t n)
 {
+	char s[5];
 	uint8_t rxdr, readlen, pdlen, maxlen;
 
+	pdlen = 0;
 	disable_chip();
 
-	rxdr = read_reg(0x07) & ~(1 << 6);
-	if (!rxdr) {
-		uart_write_line("ERROR: RX_DR=0, abort read");
-		return 0;
-	}
-
 	pdlen = rx_pdlen();	
-	if (pdlen > MAXPDLEN) {
+	if (pdlen == 0) {
 		flush_rx();
 		reset_irqs();
-		uart_write_line("ERROR: PDLEN > MAXPDLEN, abort read");
+		uart_write_line("ERROR: PDLEN = 0, abort read");
 		return 0;
 	}
 
+	// for some reason, PDLEN reads as 64 causing the below check to fail
+	//if (pdlen > MAXPDLEN) {
+	//	flush_rx();
+	//	reset_irqs();
+	//	uart_write_line("ERROR: PDLEN > MAXPDLEN, abort read");
+	//	return 0;
+	//}
+
 	maxlen = pdlen < n ? pdlen : n;
 
 	SPI_PORT &= ~(1 << SPI_SS);
@@ -319,9 +323,9 @@ uint8_t radio_recv(char *buf, uint8_t n)
 	}
 	SPI_PORT |= (1 << SPI_SS);
 
-	if (pdlen != n)
-		flush_rx();
+	flush_rx();
 	reset_irqs();
-
+	enable_chip();
+	
 	return readlen;
 }
diff --git a/recv.c b/recv.c
index 7217e47..70006dc 100644
--- a/recv.c
+++ b/recv.c
@@ -1,6 +1,7 @@
 #include <stdint.h>
 #include <string.h>
 #include <avr/interrupt.h>
+#include <util/delay.h>
 
 #include "nrfm.h"
 #include "uart.h"
@@ -36,14 +37,17 @@ int main(void)
 
 	for (;;) {
 		if (rxdr) {
+			uart_write_line("IRQ recv, reading data");
 			n = radio_recv(buf, MAXPDLEN);
 			buf[n] = '\0';
 			rxdr = 0;
-			uart_write("INFO: ");
-			uart_write_line(buf);
-			
-			radio_listen();
-			sei();
+			if (n > 0) {
+				uart_write("INFO: ");
+				uart_write_line(buf);
+			}
+		} else {
+			uart_write_line("No IRQ");
+			_delay_ms(2000);
 		}
 	}
 
@@ -52,7 +56,5 @@ int main(void)
 
 ISR(RX_PCINTVEC)
 {
-	cli();
-	uart_write_line("IRQ detected");
 	rxdr = 1;
 }
-- 
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