Matrix user forums

hi all,
mr ben,

please check my flowcode attached and cct diagram .
my idea is getting keypad number and unit id via rs232 later 485 previosly you adviced.
this time i added extra barcode scanner branded as"metrologic" sending scan numbers via rs 232 .
i use one wire only Txto get number to ic in scan mode activated by user using toggle switch port A0.
if port A0 deactivated it will in number tansmitting mode and i built cct and working nicely..can i recive scaner data with my flow code program do it need modifications.please advice.

best regards,
nuwan

Hello,

I'm not sure it the circuit will work as is to allow you to receive data from the scanner. The problem is that the RX pin from the scanner will be fighting with the RX pin from the MAX232 chip. What you could do is something like this which will allow you to control the source to the RX pin on the microcontroller. You could probably replace the transistors with a logic multipler IC if this would be easier.

hi ben,

ok i use 4016 ic for switching max and scanner.
scanner send string data and i can read directly via com port in pc.can we want to use voltage level matching before send data to ic pin.my scanner is metrologic model ms9540.

is the delay use in scanner mod enough to catch the scanner data and send with unit id.
i modified flowcode.plse check.