BS2p40 serin/serout problems

Archiver

Hi everybody,


Here is my problem: I have two bs2p40 and I try to make them
communicate via an I/O pin. I'm using the circuit and the source code
shown in the bs manual, so everything should work, but that's not the
case. In fact there is no communication, and yes, I'm sure I have the
right command parameters for the sender and receiver. The strange
thing is that if I'm not using a flow control pin, it works, but as
expected, the receiver misses data. If you have any ideas, solutions,
please let me know.

A desperate man.

Archiver

1. If you're using 'flow control', you must have two pins,
plus a common ground (or a ground wire).
-- do you have a common ground?

2. For flow control to work, the 'Reciever' must wait on
the SERIN at some point, setting the flow control pin
to 'go'. The SEROUT side will wait until it sees this
before it sends.

3. You probably want to put a 220 ohm resistor in both
the flow line and the data line. This prevents pin
damage in the case where you inadvertently try to drive
either pin from both sides at the same time.

4. You don't mention how far apart the two modules are.
I assume it is trivial (on the same board). If it is
a respectable distance (like 50 feet) you may need a
driver chip (like the MAX232 for 232, or a 485 driver).

--- In basicstamps@yahoogroups.com, "robot_cegepat"
<robot_cegepat@y...> wrote:
> Hi everybody,
>
>
> Here is my problem: I have two bs2p40 and I try to make them
> communicate via an I/O pin. I'm using the circuit and the source
code
> shown in the bs manual, so everything should work, but that's not
the
> case. In fact there is no communication, and yes, I'm sure I have
the
> right command parameters for the sender and receiver. The strange
> thing is that if I'm not using a flow control pin, it works, but as
> expected, the receiver misses data. If you have any ideas,
solutions,
> please let me know.
>
> A desperate man.