From 124e0bb43a4e45a83e5670744a652bb5cd40efcf Mon Sep 17 00:00:00 2001
From: redfast00 <redfast00@gmail.com>
Date: Sat, 31 Jul 2021 22:21:48 +0200
Subject: [PATCH] Check initialization of CAN module (untested)

---
 lib/obus_can.cpp    | 17 +++++++++++++++--
 lib/obus_can.h      |  4 +++-
 lib/obus_module.cpp | 28 ++++++++++++++--------------
 3 files changed, 32 insertions(+), 17 deletions(-)

diff --git a/lib/obus_can.cpp b/lib/obus_can.cpp
index 2e32f62..c527fd8 100644
--- a/lib/obus_can.cpp
+++ b/lib/obus_can.cpp
@@ -76,11 +76,24 @@ uint8_t payload_type(uint8_t module_type, uint8_t module_id, uint8_t msg_type) {
 }
 
 
-void init() {
+bool init() {
 	is_init = true;
 	mcp2515.reset();
 	mcp2515.setBitrate(CAN_50KBPS);
-	mcp2515.setNormalMode();
+	mcp2515.setLoopbackMode();
+	struct can_frame test_msg;
+	test_msg.can_id = 0x01;
+	test_msg.can_dlc = 1;
+	test_msg.data[0] = 0x23;
+	mcp2515.sendMessage(&test_msg);
+	struct can_frame recv_msg;
+	delay(50);
+	if (mcp2515.readMessage(&recv_msg) == MCP2515::ERROR_OK && recv_msg.can_id == 0x01 && recv_msg.can_dlc == 1 && recv_msg.data[0] == 0x23) {
+		mcp2515.setNormalMode();
+		return true;
+	} else {
+		return false;
+	}
 }
 
 
diff --git a/lib/obus_can.h b/lib/obus_can.h
index e8801a5..7f23274 100644
--- a/lib/obus_can.h
+++ b/lib/obus_can.h
@@ -91,8 +91,10 @@ uint8_t payload_type(uint8_t module_type, uint8_t message_type);
 
 /**
  * Initialize the CAN controller for OBUS messaging
+ *
+ * @return true if initialization and self-test succeeded, false otherwise
  */
-void init();
+bool init();
 /**
  * Receive a message
  *
diff --git a/lib/obus_module.cpp b/lib/obus_module.cpp
index 87f0fd8..bd758f5 100644
--- a/lib/obus_module.cpp
+++ b/lib/obus_module.cpp
@@ -76,6 +76,16 @@ void _setLedBlink(struct color color, uint16_t delay) {
 	_ledLoop();
 }
 
+void blink_error(String message) {
+	bool blink = false;
+	while (true) {
+		digitalWrite(PIN_LED_RED, blink);
+		digitalWrite(PIN_LED_GREEN, blink);
+		blink = !blink;
+		delay(blink ? BLINK_DELAY_SLOW : BLINK_DELAY_FAST);
+		Serial.println(message);
+	}
+}
 
 void _resetState() {
 	strike_count = 0;
@@ -93,10 +103,11 @@ void _resetState() {
 void setup(uint8_t type, uint8_t id) {
 	this_module.type = type;
 	this_module.id = id;
-
-	obus_can::init();
-
 	_resetState();
+
+	if (!obus_can::init()) {
+		blink_error(F("CAN init failed"));
+	}
 }
 
 void empty_callback_info(uint8_t info_id, uint8_t infomessage[7]) {
@@ -113,17 +124,6 @@ void empty_callback_state(uint32_t time_left, uint8_t strikes, uint8_t max_strik
 	(void)puzzle_modules_left;
 }
 
-void blink_error(String message) {
-	bool blink = false;
-	while (true) {
-		digitalWrite(PIN_LED_RED, blink);
-		digitalWrite(PIN_LED_GREEN, blink);
-		blink = !blink;
-		delay(blink ? BLINK_DELAY_SLOW : BLINK_DELAY_FAST);
-		Serial.println(message);
-	}
-}
-
 bool loopPuzzle(obus_can::message* message, void (*callback_game_start)(uint8_t puzzle_modules), void (*callback_game_stop)(), void (*callback_info)(uint8_t info_id, uint8_t infomessage[7]), void (*callback_state)(uint32_t time_left, uint8_t strikes, uint8_t max_strikes, uint8_t puzzle_modules_left)) {
 	// TODO this can be more efficient by only enabling error interrupts and
 	//  reacting to the interrupt instead of checking if the flag is set in a loop