AP_Scripting: refresh serial bindings

libraries/AP_Scripting/AP_Scripting_SerialAccess.cpp

@@ -24,9 +24,9 @@ void AP_Scripting_SerialAccess::begin(uint32_t baud)
     }
 }
 
-size_t AP_Scripting_SerialAccess::write(uint8_t c)
+bool AP_Scripting_SerialAccess::write(uint8_t c)
 {
-    return write(&c, 1);
+    return write(&c, 1) > 0;
 }
 
 size_t AP_Scripting_SerialAccess::write(const uint8_t *buffer, size_t size)
@@ -37,13 +37,9 @@ size_t AP_Scripting_SerialAccess::write(const uint8_t *buffer, size_t size)
     return ON_DEVICE_PORT(write, buffer, size);
 }
 
-int16_t AP_Scripting_SerialAccess::read(void)
+bool AP_Scripting_SerialAccess::read(uint8_t &c)
 {
-    uint8_t c;
-    if (read(&c, 1) != 1) {
-        return -1;
-    }
-    return c;
+    return read(&c, 1) > 0;
 }
 
 ssize_t AP_Scripting_SerialAccess::read(uint8_t* buffer, uint16_t count)
@@ -54,12 +50,15 @@ ssize_t AP_Scripting_SerialAccess::read(uint8_t* buffer, uint16_t count)
     return ON_DEVICE_PORT(read, buffer, count);
 }
 
-uint32_t AP_Scripting_SerialAccess::available(void)
+int32_t AP_Scripting_SerialAccess::available(void)
 {
+    uint32_t avail;
     if (!check_is_device_port()) {
-        return stream->available();
+        avail = stream->available();
+    } else {
+        avail = ON_DEVICE_PORT(available);
     }
-    return ON_DEVICE_PORT(available);
+    return MIN(avail, (uint32_t)INT32_MAX); // ensure result fits in a Lua integer
 }
 
 void AP_Scripting_SerialAccess::set_flow_control(enum AP_HAL::UARTDriver::flow_control fcs)

libraries/AP_Scripting/AP_Scripting_SerialAccess.h

@@ -14,13 +14,13 @@ class AP_Scripting_SerialAccess {
 
     void begin(uint32_t baud);
 
-    size_t write(uint8_t c);
+    bool write(uint8_t c);
     size_t write(const uint8_t *buffer, size_t size);
 
-    int16_t read(void);
+    bool read(uint8_t &c);
     ssize_t read(uint8_t *buffer, uint16_t count);
 
-    uint32_t available(void);
+    int32_t available(void);
 
     void set_flow_control(enum AP_HAL::UARTDriver::flow_control fcs);
 

libraries/AP_Scripting/docs/docs.lua

@@ -1234,12 +1234,12 @@ function AP_HAL__I2CDevice_ud:set_retries(retries) end
 local AP_Scripting_SerialAccess_ud = {}
 
 -- Start serial port with the given baud rate (no effect for device ports)
----@param baud_rate uint32_t_ud|integer|number
+---@param baud_rate integer
 function AP_Scripting_SerialAccess_ud:begin(baud_rate) end
 
 -- Writes a single byte
 ---@param value integer -- byte to write
----@return uint32_t_ud -- 1 if success else 0
+---@return boolean -- true if successfully written
 function AP_Scripting_SerialAccess_ud:write(value) end
 
 -- Writes a string. The number of bytes actually written, i.e. the length of the
@@ -1250,7 +1250,7 @@ function AP_Scripting_SerialAccess_ud:write(value) end
 function AP_Scripting_SerialAccess_ud:writestring(data) end
 
 -- Reads a single byte from the serial port
----@return integer -- byte, -1 if error or none available
+---@return integer|nil -- byte, or nil on error/none available
 function AP_Scripting_SerialAccess_ud:read() end
 
 -- Reads up to `count` bytes and returns the bytes read as a string. No bytes
@@ -1260,7 +1260,7 @@ function AP_Scripting_SerialAccess_ud:read() end
 function AP_Scripting_SerialAccess_ud:readstring(count) end
 
 -- Returns number of available bytes to read.
----@return uint32_t_ud
+---@return integer
 function AP_Scripting_SerialAccess_ud:available() end
 
 -- Set flow control option for serial port (no effect for device ports)

libraries/AP_Scripting/drivers/EFI_DLA.lua

@@ -75,7 +75,9 @@ end
 local function read_bytes(n)
    local ret = ""
    for _ = 1, n do
-      ret = ret .. string.char(uart:read())
+      local b = uart:read()
+      assert(b)
+      ret = ret .. string.char(b)
    end
    return ret
 end
@@ -88,7 +90,7 @@ state.total_fuel_cm3 = 0.0
    check for input and parse data
 --]]
 local function check_input()
-   local n_bytes = uart:available():toint()
+   local n_bytes = uart:available()
    --gcs:send_text(MAV_SEVERITY.INFO, string.format("n_bytes=%u %.2f", n_bytes, millis():tofloat()*0.001))
    if n_bytes < 82 then
       return
@@ -108,7 +110,7 @@ local function check_input()
    state.last_read_us = micros()
 
    -- discard the rest
-   discard_bytes(uart:available():toint())
+   discard_bytes(uart:available())
 end
 
 --[[

libraries/AP_Scripting/drivers/Generator_SVFFI.lua

@@ -69,7 +69,9 @@ end
 local function read_bytes(n)
    local ret = ""
    for _ = 1, n do
-      ret = ret .. string.char(uart:read())
+      local b = uart:read()
+      assert(b)
+      ret = ret .. string.char(b)
    end
    return ret
 end
@@ -149,7 +151,7 @@ state.last_status = -1
    check for input and parse data
 --]]
 local function check_input()
-   local n_bytes = uart:available():toint()
+   local n_bytes = uart:available()
    --gcs:send_text(MAV_SEVERITY.INFO, string.format("n_bytes=%u %.2f", n_bytes, millis():tofloat()*0.001))
    if n_bytes < 31 then
       return

libraries/AP_Scripting/drivers/Hobbywing_DataLink.lua

@@ -67,7 +67,9 @@ uart:begin(115200)
 local function read_bytes(n)
    local ret = ""
    for _ = 1, n do
-      ret = ret .. string.char(uart:read())
+      local b = uart:read()
+      assert(b)
+      ret = ret .. string.char(b)
    end
    return ret
 end
@@ -76,7 +78,7 @@ end
    discard pending bytes
 --]]
 local function discard_pending()
-   local n = uart:available():toint()
+   local n = uart:available()
    for _ = 1, n do
       uart:read()
    end
@@ -168,7 +170,7 @@ local telem_data = ESCTelemetryData()
    check for input and parse data
 --]]
 local function check_input()
-   local n_bytes = uart:available():toint()
+   local n_bytes = uart:available()
    if n_bytes < 160 then
       return
    end

libraries/AP_Scripting/drivers/INF_Inject.lua

@@ -140,6 +140,7 @@ local function read_bytes(n)
    local ret = ""
    for _ = 1, n do
       local b = uart:read()
+      assert(b)
       state.chk0 = state.chk0 ~ b
       state.chk1 = state.chk1 ~ state.chk0
       ret = ret .. string.char(b)
@@ -168,7 +169,7 @@ end
 --]]
 local function check_input()
    local packet_size = 83
-   local n_bytes = uart:available():toint()
+   local n_bytes = uart:available()
    if n_bytes < packet_size then
       return false
    end

libraries/AP_Scripting/examples/readstring_test.lua

@@ -17,6 +17,7 @@ local function get_string_44(n)
    local ret = ""
    for _ = 1, n do
       local b = port:read()
+      assert(b)
       ret = ret .. string.char(b)
    end
    return ret
@@ -32,14 +33,14 @@ end
 
 function update()
    -- test using 4.5 method
-   local n = port:available():toint()
+   local n = port:available()
    if n > 0 then
       local str = get_string_45(n)
       gcs:send_text(0, string.format("Received: '%s'", str))
    end
 
    -- test using 4.4 method (just so we don't have an unused function in lua check)
-   n = port:available():toint()
+   n = port:available()
    if n > 0 then
       local str = get_string_44(n)
       gcs:send_text(0, string.format("Received: '%s'", str))

libraries/AP_Scripting/generator/description/bindings.desc

@@ -395,12 +395,12 @@ singleton RC_Channels method get_aux_cached boolean RC_Channel::AUX_FUNC'enum 0
 include AP_Scripting/AP_Scripting_SerialAccess.h
 -- don't let user create access objects
 userdata AP_Scripting_SerialAccess creation null -1
-userdata AP_Scripting_SerialAccess method begin void uint32_t 1U UINT32_MAX
-userdata AP_Scripting_SerialAccess method write uint32_t uint8_t'skip_check
+userdata AP_Scripting_SerialAccess method begin void int32_t 1 INT32_MAX
+userdata AP_Scripting_SerialAccess method write boolean uint8_t'skip_check
 userdata AP_Scripting_SerialAccess manual writestring lua_serial_writestring 1 1
-userdata AP_Scripting_SerialAccess method read int16_t
+userdata AP_Scripting_SerialAccess manual read lua_serial_read 0 1
 userdata AP_Scripting_SerialAccess manual readstring lua_serial_readstring 1 1
-userdata AP_Scripting_SerialAccess method available uint32_t
+userdata AP_Scripting_SerialAccess method available int32_t
 userdata AP_Scripting_SerialAccess method set_flow_control void AP_HAL::UARTDriver::flow_control'enum AP_HAL::UARTDriver::FLOW_CONTROL_DISABLE AP_HAL::UARTDriver::FLOW_CONTROL_RTS_DE
 
 -- serial is not a real C++ type here, but its name never gets used in C++ as we only have manual methods

libraries/AP_Scripting/lua_bindings.cpp

@@ -792,6 +792,7 @@ int lua_serial_writestring(lua_State *L)
     // get the bytes the user wants to write, along with their length
     size_t req_bytes;
     const char *data = lua_tolstring(L, 2, &req_bytes);
+    req_bytes = MIN(req_bytes, (size_t)INT32_MAX); // ensure result fits in a Lua integer
 
     // write up to that number of bytes
     const uint32_t written_bytes = port->write((const uint8_t*)data, req_bytes);
@@ -802,6 +803,21 @@ int lua_serial_writestring(lua_State *L)
     return 1;
 }
 
+int lua_serial_read(lua_State *L) {
+    binding_argcheck(L, 1);
+
+    AP_Scripting_SerialAccess * port = check_AP_Scripting_SerialAccess(L, 1);
+
+    uint8_t c;
+    if (port->read(c)) {
+        lua_pushinteger(L, c);
+    } else {
+        lua_pushnil(L); // error, return nil
+    }
+
+    return 1;
+}
+
 int lua_serial_readstring(lua_State *L) {
     binding_argcheck(L, 2);
 
@@ -814,13 +830,13 @@ int lua_serial_readstring(lua_State *L) {
 
     // read up to that number of bytes
     const ssize_t read_bytes = port->read(data, req_bytes);
-    if (read_bytes < 0) {
-        return 0; // error, return nil
+    if (read_bytes >= 0) {
+        // push the buffer as a string, truncated to the number of bytes actually read
+        luaL_pushresultsize(&b, read_bytes);
+    } else {
+        lua_pushnil(L); // error, return nil
     }
 
-    // push the buffer as a string, truncated to the number of bytes actually read
-    luaL_pushresultsize(&b, read_bytes);
-
     return 1;
 }
 

libraries/AP_Scripting/lua_bindings.h

@@ -13,6 +13,7 @@ int lua_get_CAN_device2(lua_State *L);
 int lua_serial_find_serial(lua_State *L);
 int lua_serial_find_simulated_device(lua_State *L);
 int lua_serial_writestring(lua_State *L);
+int lua_serial_read(lua_State *L);
 int lua_serial_readstring(lua_State *L);
 int lua_dirlist(lua_State *L);
 int lua_removefile(lua_State *L);

libraries/AP_Scripting/tests/serial_loopback.lua

@@ -11,7 +11,7 @@ function test_driver_to_device()
   local msg_send = "hello device"
   local num_sent = 0
   for ci = 1,#msg_send do
-    num_sent = num_sent + ser_driver:write(msg_send:byte(ci, ci)):toint()
+    num_sent = num_sent + (ser_driver:write(msg_send:byte(ci, ci)) and 1 or 0)
   end
   local msg_recv = ser_device:readstring(#msg_send)
   if msg_send == msg_recv and num_sent == #msg_send then