Problem interfacing ADXL202 and Accustar Clinometer with 16F876A

[mister_e]

You're right. With a resistor in serie that will work.

[Beatrix]

You're right. With a resistor in serie that will work.

Hmm..that might be part of my problem. Right now I have pin C6 connected to pin 3 of the RS232 connector and pin C7 connected to pin 2 directly (no resistor in series). What resistor would you recomend? That and would I need to use any of the other pins on the RS232 connector (request to send, etc) if just reading trhe data via HyperTerminal or Microsode Studio?

[NavMicroSystems]

Hmm..that might be part of my problem. Right now I have
pin C6 connected to pin 3 of the RS232 connector and
pin C7 connected to pin 2 directly (no resistor in series). What resistor would you recomend?
That and would I need to use any of the other pins on the RS232 connector (request to send, etc) if just reading trhe data via HyperTerminal or Microsode Studio?

Beatrix,

On the second PIC (I guess that's the one to transfer data to the PC) you are using PortB.0 with SERIN
I assume that's the incomming Data from the first PIC.

And you are using PortC.7 with SEROUT
I assume that's the outgoing Data to the PC.
A series resistor is not really required on the PC's RX-Pin.
(But 1k wouldn't hinder either)

Since the PIC does not receive any Data from the PC
you don't need a connection between PortC.6 and Pin3 on the RS232.
If you want to connect it you should have a series resistor (say 22k).

All you actually need are two wires:
PortC.7 to RS232 Pin 2
and
PIC GND (Vss) to RS232 Pin 5

Is it probably the missing GND that is causing the Problem?

Set the Handshake in Hyperterm to "NONE"

Simple test of your PCs serial Port:
With nothing connected to the RS232
In Hyperterm set "Local Echo" to "OFF"
when type on your keyboard there should nothing appear on your screen.

Now connect Pin 2 and Pin 3 on the RS232
every character typed should be echoed back on the screen.

[Beatrix]

Regarding the connection to ground: currently I have both of the Vss pins connected to board ground. For this connection to RS232 ground, should I simply solder in a wire, thereby having Vss connected to board ground and RS232 ground, or should I disconnect it from board ground and only connect it to RS232 ground?

[NavMicroSystems]

...having Vss connected to board ground and RS232 ground...

That's the way it should be.

[Beatrix]

I tried it again with the ground wire in place and no more receive wire using both Microcode Studio and HyperTerminal, and it still doesn't work. Is there anything I should be doing with the other pins on the RS232 connector? Any ideas?

[NavMicroSystems]

Beatrix,

have you tried the simple test described here

Have you set the Baudrate on the PC-side correctly
and is "Handshake" set to none?

Could you post a schematic and your code (cut down to the RS232 part)

For a one-way communication (PIC --> PC) you definitely need only two wires:
PIC-GND to PC-GND and PTC-TX to PC-RX

Probably your PCs COM-Port doesn't work with TTL-Levels.
If so you would need to add a MAX232-type of Level shifter.