uart working

8 files changed, 34 insertions, 17 deletions

diff --git a/nicla/serial_test.py b/nicla/serial_test.py
index bef43a2..c8b84e5 100644
--- a/nicla/serial_test.py
+++ b/nicla/serial_test.py
@@ -1,21 +1,22 @@
-from pyb import Pin, delay
+from pyb import Pin, delay, udelay
 
 zumo_tx = Pin("PA10", Pin.IN)
 zumo_rx = Pin("PA9", Pin.OUT_PP)
 
-def uart_send(s):
+def uart_send(byte):
     zumo_rx.value(0)
-    byte = ord(s)
-    print("START BIT")
-    delay(2)
+    udelay(1000)
     for x in range(8):
         bit = (byte & (1 << 7)) >> 7
         byte <<= 1
         zumo_rx.value(bit)
-        print(f"BIT[{x}] = {bit}")
-        delay(2)
-    print("STOP BIT")
+        udelay(1000)
     zumo_rx.value(1)
 
 while True:
-    uart_send("a")
+    # uart_send("a")
+    for x in range(8):
+        n = 1 << x
+        uart_send(n)
+        print(f"0x{n:02x}")
+        delay(1000)
diff --git a/zumo/.gitignore b/zumo/.gitignore
index e45f7a2..5761abc 100644
--- a/zumo/.gitignore
+++ b/zumo/.gitignore
@@ -1,2 +1 @@
 *.o
-pidtest
diff --git a/zumo/pidtest/.gitignore b/zumo/pidtest/.gitignore
new file mode 100644
index 0000000..41dc46e
--- /dev/null
+++ b/zumo/pidtest/.gitignore
@@ -0,0 +1 @@
+pidtest
diff --git a/zumo/pidtest.mk b/zumo/pidtest/makefile
index 5ffe1e1..832d60b 100644
--- a/zumo/pidtest.mk
+++ b/zumo/pidtest/makefile
@@ -5,8 +5,8 @@ CFLAGS =
 LFLAGS =
 TARGET = pidtest
 
-SRCS := pidtest.cpp pid.cpp
-OBJS := pidtest.o pid.o
+SRCS := pidtest.cpp ../pid.cpp
+OBJS := pidtest.o ../pid.o
 
 all: pidtest
 
diff --git a/zumo/pidtest.cpp b/zumo/pidtest/pidtest.cpp
index b9ce50b..4d047fb 100644
--- a/zumo/pidtest.cpp
+++ b/zumo/pidtest/pidtest.cpp
@@ -1,7 +1,7 @@
 #include <cstdio>
 #include <random>
 
-#include "pid.h"
+#include "../pid.h"
 
 int main() {
 	float P, I, D;
diff --git a/zumo/protocol.cpp b/zumo/protocol.cpp
index fea8a00..f11827c 100644
--- a/zumo/protocol.cpp
+++ b/zumo/protocol.cpp
@@ -1,4 +1,6 @@
 #include <Zumo32U4Motors.h>
+#include <Arduino.h>
+#include <Wire.h>
 
 #include "protocol.h"
 
@@ -34,6 +36,20 @@ void apply_state(dui_state_t *state) {
 	// TODO: print sign on OLED screen
 }
 
+inline bool rx() { return !digitalRead(DUI_PINOUT_NICLA_RX); }
+
 unsigned char uart_read() {
-	return 0x00;
+	if (rx() == true) return 0x00; // return immediately if line is idle
+
+	delayMicroseconds(1500); // wait out start bit
+
+	unsigned char byte = 0x00;
+	for (unsigned int i = 0; i < 8; i++) {
+		byte = (byte << 1) | rx();
+		delayMicroseconds(1000);
+	}
+
+	delayMicroseconds(1000); // wait out stop bit
+
+	return byte;
 }
diff --git a/zumo/protocol.h b/zumo/protocol.h
index 662a5ce..9db7902 100644
--- a/zumo/protocol.h
+++ b/zumo/protocol.h
@@ -1,5 +1,8 @@
 #pragma once
 
+#define DUI_PINOUT_NICLA_TX 13
+#define DUI_PINOUT_NICLA_RX 14
+
 typedef enum {
 	DUI_CMD_NULL,
 	DUI_CMD_SIGN,
diff --git a/zumo/zumo.ino b/zumo/zumo.ino
index c65c2f9..e53513b 100644
--- a/zumo/zumo.ino
+++ b/zumo/zumo.ino
@@ -5,9 +5,6 @@
 #include "protocol.h"
 #include "pid.h"
 
-#define DUI_PINOUT_NICLA_TX 13
-#define DUI_PINOUT_NICLA_RX 14
-
 dui_state_t g_dui_target_state = {
 	.steer = 1.0f,
 	.speed = 1.0f,