- Fri Apr 11, 2008 11:44 pm
#46289
Hi All,
For my project I need to get an XBee radio talking to an RS-232 serial port, which I have done via an SN7404 Hex Inverter, but it is acting very strange. I decided to use a Texas Instruments SN7404N after a Maxim MAX232CPE decided not to work at all (I was using 1uF tantalum caps, I think I might need 10uF)
I am using a 7404 as most RS-232 transceivers only come with 2 drivers (rx, tx) but I need rts and dtr also, so a 7404 was the feasible solution.
The circuit works - I can use the X-CTU terminal to transfer text between 2 xbee's on 2 separate pc's in the X-CTU terminal, no worries at all. The issue is that the XBee responds weirdly when X-CTU sends '+++'. I can send '+++' in the terminal and I get 'OK.' when X-CTU sends it, all I get back is 'O' so I assume the transmission is being cut.
I have a USB debug board which X-CTU can use to interface with both XBee's fine, just when I use the 7404 circuit. I am using the correct baud rates.
It seems to be narrowed down to the 7404 circuit. Are there any issues with the SN7404N I should know, like connecting the unused pins to GND or VCC?
Why would it send data fine in the X-CTU terminal, and then get a weird response when I press 'Test/Query' Both modems do this. I have turned CTS flow control off.
Any suggestions would be greatly appreciated.
For my project I need to get an XBee radio talking to an RS-232 serial port, which I have done via an SN7404 Hex Inverter, but it is acting very strange. I decided to use a Texas Instruments SN7404N after a Maxim MAX232CPE decided not to work at all (I was using 1uF tantalum caps, I think I might need 10uF)
I am using a 7404 as most RS-232 transceivers only come with 2 drivers (rx, tx) but I need rts and dtr also, so a 7404 was the feasible solution.
The circuit works - I can use the X-CTU terminal to transfer text between 2 xbee's on 2 separate pc's in the X-CTU terminal, no worries at all. The issue is that the XBee responds weirdly when X-CTU sends '+++'. I can send '+++' in the terminal and I get 'OK.' when X-CTU sends it, all I get back is 'O' so I assume the transmission is being cut.
I have a USB debug board which X-CTU can use to interface with both XBee's fine, just when I use the 7404 circuit. I am using the correct baud rates.
It seems to be narrowed down to the 7404 circuit. Are there any issues with the SN7404N I should know, like connecting the unused pins to GND or VCC?
Why would it send data fine in the X-CTU terminal, and then get a weird response when I press 'Test/Query' Both modems do this. I have turned CTS flow control off.
Any suggestions would be greatly appreciated.