From ab1d0d53f3ce88384f37ad91b9a6f731e251583e Mon Sep 17 00:00:00 2001
From: Andy Piper <github@andypiper.com>
Date: Sun, 2 Aug 2020 07:59:13 +0100
Subject: [PATCH] AP_Camera: keep trying to initialize RunCam after boot

---
 libraries/AP_Camera/AP_RunCam.cpp | 38 +++++++++++++++----------------
 libraries/AP_Camera/AP_RunCam.h   |  4 ++--
 2 files changed, 20 insertions(+), 22 deletions(-)

diff --git a/libraries/AP_Camera/AP_RunCam.cpp b/libraries/AP_Camera/AP_RunCam.cpp
index 7bc8d7ffd8..cf2c7b9cc2 100644
--- a/libraries/AP_Camera/AP_RunCam.cpp
+++ b/libraries/AP_Camera/AP_RunCam.cpp
@@ -103,7 +103,7 @@ AP_RunCam::Request::Length AP_RunCam::Request::_expected_responses_length[RUNCAM
 // the protocol for Runcam Device definition
 static const uint8_t RUNCAM_HEADER = 0xCC;
 static const uint8_t RUNCAM_OSD_MENU_DEPTH = 2;
-static const uint32_t RUNCAM_INIT_INTERVAL_MS = 500;
+static const uint32_t RUNCAM_INIT_INTERVAL_MS = 1000;
 static const uint32_t RUNCAM_OSD_UPDATE_INTERVAL_MS = 100; // 10Hz
 
 // menu structures of runcam devices
@@ -156,7 +156,7 @@ void AP_RunCam::init()
         _in_menu = -1;
     }
 
-    uart->begin(115200);
+    start_uart();
 
     // first transition is from initialized to ready
     _transition_start_ms = AP_HAL::millis();
@@ -762,11 +762,24 @@ void AP_RunCam::drain()
     uart->discard_input();
 }
 
+// start the uart if we have one
+void AP_RunCam::start_uart()
+{
+    // 8N1 communication
+    uart->configure_parity(0);
+    uart->set_stop_bits(1);
+    uart->set_flow_control(AP_HAL::UARTDriver::FLOW_CONTROL_DISABLE);
+    uart->set_blocking_writes(false);   // updates run in the main thread
+    uart->set_options(uart->get_options() | AP_HAL::UARTDriver::OPTION_NODMA_TX | AP_HAL::UARTDriver::OPTION_NODMA_RX);
+    uart->begin(115200, 10, 10);
+    uart->discard_input();
+}
+
 // get the device info (firmware version, protocol version and features)
 void AP_RunCam::get_device_info()
 {
-    send_request_and_waiting_response(Command::RCDEVICE_PROTOCOL_COMMAND_GET_DEVICE_INFO, 0, RUNCAM_INIT_INTERVAL_MS,
-        _boot_delay_ms / RUNCAM_INIT_INTERVAL_MS, FUNCTOR_BIND_MEMBER(&AP_RunCam::parse_device_info, void, const Request&));
+    send_request_and_waiting_response(Command::RCDEVICE_PROTOCOL_COMMAND_GET_DEVICE_INFO, 0, RUNCAM_INIT_INTERVAL_MS * 4,
+        -1, FUNCTOR_BIND_MEMBER(&AP_RunCam::parse_device_info, void, const Request&));
 }
 
 // map a Event to a SimulationOperation
@@ -911,22 +924,6 @@ void AP_RunCam::send_packet(Command command, uint8_t param)
     uart->flush();
 }
 
-uint8_t AP_RunCam::crc8_high_first(uint8_t *ptr, uint8_t len)
-{
-    uint8_t crc = 0x00;
-    while (len--) {
-        crc ^= *ptr++;
-        for (uint8_t i = 8; i > 0; --i) {
-            if (crc & 0x80) {
-                crc = (crc << 1) ^ 0x31;
-            } else {
-                crc = (crc << 1);
-            }
-        }
-    }
-    return (crc);
-}
-
 // handle a device info response
 void AP_RunCam::parse_device_info(const Request& request)
 {
@@ -987,6 +984,7 @@ bool AP_RunCam::request_pending(uint32_t now)
     if (_pending_request._max_retry_times > 0) {
         // request timed out, so resend
         debug("retrying[%d] command 0x%X, op 0x%X\n", int(_pending_request._max_retry_times), int(_pending_request._command), int(_pending_request._param));
+        start_uart();
         _pending_request._device->send_packet(_pending_request._command, _pending_request._param);
         _pending_request._recv_response_length = 0;
         _pending_request._request_timestamp_ms = now;
diff --git a/libraries/AP_Camera/AP_RunCam.h b/libraries/AP_Camera/AP_RunCam.h
index 56f07304e5..b3e90ca3e8 100644
--- a/libraries/AP_Camera/AP_RunCam.h
+++ b/libraries/AP_Camera/AP_RunCam.h
@@ -379,6 +379,8 @@ private:
     void receive();
     // empty the receive side of the serial port
     void drain();
+    // start the uart with appropriate settings
+    void start_uart();
 
     // get the RunCam device information
     void get_device_info();
@@ -399,8 +401,6 @@ private:
         uint16_t maxRetryTimes, parse_func_t parseFunc);
     // send a packet to the serial port
     void send_packet(Command command, uint8_t param);
-    // crc functions
-    static uint8_t crc8_high_first(uint8_t *ptr, uint8_t len);
     // handle a device info response
     void parse_device_info(const Request& request);
     // wait for the RunCam device to be fully ready