Just realized that my error checking might not have been working while I was troubleshooting for first lua application using the "luars232" library. Firstly, a snippet in question, which is pretty much lifted from the sample available as part of library, with just 1 variable-name changed ('rs232' changed to 'serial').
[code]
local e, p = serial.open(port)
if e ~= serial.RS232_ERR_NOERR then
-- handle error (TODO: change to logging)
out:write(string.format("Can't open serial port '%s', error: '%s'\n",
port, serial.error_tostring(e)))
return
end
assert(p:set_baud_rate(serial.RS232_BAUD_115200) == serial.RS232_ERR_NOERROR
assert(p:set_data_bits(serial.RS232_DATA_8) == serial.RS232_ERR_NOERROR)
assert(p:set_parity(serial.RS232_PARITY_NONE) == serial.RS232_ERR_NOERROR)
assert(p:set_stop_bits(serial.RS232_STOP_1) == serial.RS232_ERR_NOERROR)
assert(p:set_flow_control(serial.RS232_FLOW_OFF) == serial.RS232_ERR_NOERROR)
-- handle error (TODO: change to logging)
out:write(string.format("OK, port open with values '%s'\n", tostring(p)))
-- read with timeout
local read_len = 1 -- read one byte
local timeout = 100 -- in miliseconds
local err, data_read, size = p:read(read_len, timeout)
assert(e == serial.RS232_ERR_NOERROR)