Odd Parity for BS2?
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Posts: 46,084
Regarding my Question about the RS-232 interface:
I been reading some information on the internet and I found this:
"The EIA-232 spec provides for both sync and async but PC's use a UART
(Universal Asynchronous Receiver/Transmitter) chip such as a 16450, 16550A, or
16650 and can't deal with sync."
But I can control the video camera using software on a PC computer with a 9-pin
Com port.
Even if the specification says syncron transfer.
Could it be a typing error in the specification for the communication protocol?
I used another computer to listen to the communication between the computer
running the software and the camera. The two commands that I wish to build-in
to my controller is only 3 byte long. Can I somehow make the Basic Stamp "say"
a string of ones and zeros to control the camera (adding start/stop bit & and 1
odd parity bit manually)?
I don't need to get an answer from the camera.
Or, can I get the basic stamp to use odd parity somehow?
Can I get Odd parity with any of the basic stamps?
Please help me!
Best regards
Johan Brostrom
[noparse][[/noparse]Non-text portions of this message have been removed]
I been reading some information on the internet and I found this:
"The EIA-232 spec provides for both sync and async but PC's use a UART
(Universal Asynchronous Receiver/Transmitter) chip such as a 16450, 16550A, or
16650 and can't deal with sync."
But I can control the video camera using software on a PC computer with a 9-pin
Com port.
Even if the specification says syncron transfer.
Could it be a typing error in the specification for the communication protocol?
I used another computer to listen to the communication between the computer
running the software and the camera. The two commands that I wish to build-in
to my controller is only 3 byte long. Can I somehow make the Basic Stamp "say"
a string of ones and zeros to control the camera (adding start/stop bit & and 1
odd parity bit manually)?
I don't need to get an answer from the camera.
Or, can I get the basic stamp to use odd parity somehow?
Can I get Odd parity with any of the basic stamps?
Please help me!
Best regards
Johan Brostrom
[noparse][[/noparse]Non-text portions of this message have been removed]
Comments
> The two commands that I wish to build-in to my controller
> is only 3 byte long. Can I somehow make the Basic Stamp "say" a
> string of ones and zeros to control the camera (adding start/stop
> bit & and 1 odd parity bit manually)? I don't need to get an answer
> from the camera.
Exactly what is the stream of bytes you must send, and what is the
slowest transmission (baud) rate your camera will accept? There may
be a way to get there from here...
Regards,
Steve
> Regarding my Question about the RS-232 interface:
>
> I been reading some information on the internet and I found this:
>
> "The EIA-232 spec provides for both sync and async but PC's use a UART
> (Universal Asynchronous Receiver/Transmitter) chip such as a 16450, 16550A, or
> 16650 and can't deal with sync."
Must be an asynchronous then, the DB25 pinout had pins defined for the
Clock for synchronous devices.
> But I can control the video camera using software on a PC computer with a
9-pin
> Com port. Even if the specification says syncron transfer. Could it be a
typing
> error in the specification for the communication protocol? I used another
> computer to listen to the communication between the computer running the
> software and the camera. The two commands that I wish to build-in to my
> controller is only 3 byte long. Can I somehow make the Basic Stamp "say" a
> string of ones and zeros to control the camera (adding start/stop bit & and 1
> odd parity bit manually)? I don't need to get an answer from the camera.
Doesn't look like any do odd, even in 8 bit mode. If you could get the timing
right, you might be able do toggle the pin after the serout command.
Anoter possiblity is the Maxim SPI UART, but I don't know if it will do 8 bits
plus parity.
> Or, can I get the basic stamp to use odd parity somehow?
> Can I get Odd parity with any of the basic stamps?
>
> Please help me!
>
> Best regards
>
> Johan Brostrom
>