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Serial communication problem

 I am trying to interface my arm9 based single board comp to the PICAXE 28X1 (starter kit board). The idea is to interface the single board computer running Linux to my PICAXE over serial and try to send commands to it over the serial line. I wrote code for my PICAXE that can listen on the serial line and transmit the same characters back. The arm board recives characters sent by the PICAXE but for some reason characters sent by the arm board are not recieved by the PICAXE.

I have tried both the programming serial port - serrxd/sertxd combination and the general i/o pins - serin/serout combination. In both cases the characters sent by PICAXE are visible at the arm9 minicom terminal but the reverse always fails. The output (serial Tx) is run through a 330 Ohms resistor on output pin 0.

I have observed that if i short the V and one of the input pins the serin is able to read some garbage character from the input pin. The program is pretty simple

using programming serial port

 ptr = 1 `Reset scratchpad pointer to 1
 `Read just 1 byte command to scatchpad address 1
 serrxd @ptr
 wait 1
 sertxd (@ptr)

using the general i/o pins

serin 7, N4800, b1
serout 0, N4800, (b1)

 

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Yes both the boards are running on different power supplies and i have connected the ground pin. I rigged up the arm9 board to get the TTL pins for serial Rx and Tx. With this i am able to see some garbage characters received at the PICAXE now. 

I think now its just a matter of configuring the serial port right to read the characters. Will update you guys soon. 

Seems like a fair indication of one of three problems: baud rate or the number of stop bits or parity is incorrectly set. One option would be to find out what the defaults are for your PICAXE and change the PC (or whatever terminal you're using) end as it's probably easier to change the settings there.
When you refer to the resistor on the output pin are you referring to the output pin on the PICAXE or the arm9?
What's the significance of the T and the N? Is that the difference in your language between parity and non-parity? If so, of course, boths ends needs to be set with the same parameters.