Re: [RoboBricks2] Re: Interfacing WireHost to 3.3 LVTTL serial
>The pins on the WRTSL54GS are 1 through 5 with pin 4
>being a no-connection. In addition, pin 1 is 3.3V
>which is not needed. Thus, only three wires are used:
>
>Router Pin2 => Max232 Pin 9 (TX)
>Router Pin3 => Max232 Pin 7 (RX)
>Router Pin5 => Max232 pin 11 (Ground)
>
>In addition, there is a voltage divider. I have a
>330 Ohm resistor between Max232 Pins 7 and 10.
>I have a 470 Ohm resistor between Max232 Pins 2 and 7.
>This provides a voltage divider of .5875=(470/(470+33)).
>The signal from the router comes out of router-pin3
>at between 0 and 3.3V and lands on max232-pin9 which
>is forwared to the TTL compliant input of the WireHost.
>The WireHost response comes in on Max232-pin10 a 0 to 5V
>is divided down to 0-2.93V and sent on to the router-pin2.
Hi Wayne,
Thanks for the additional information. I still have not got this
working yet.
One thing that is a little confusing to me is that above you say
>Router Pin2 => Max232 Pin 9 (TX)
and then later
>The signal from the router comes out of router-pin3
>at between 0 and 3.3V and lands on max232-pin9
I think it should say "The signal from the router comes out of
router-pin*2* ..."
Anyway, I found that I had "router pin3 -> max232 pin 9" and "router
pin2 => max232 Pin 7", so I swapped them but still no joy. I have also
built the voltage divider as you have specified.
One thing that seems a little odd to me is Ground. I've verified that
>Router Pin5 => Max232 pin 11 (Ground)
But Max232 pin 11 is not connected to Max232 pin 15. It appears it
should be in the schematic.
... http://www.hbrobotics.org/wiki/index.php5/WRTSL54GS#Using_on_board_serial_port ... Brandon: I have not posted a circuit the WireHost conversion. The longer...
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... Hi Wayne, Thanks for the additional information. I still have not got this working yet. One thing that is a little confusing to me is that above you say ...
... You are correct, that is a typo on my part. ... For revision C of WireHost, pin 11 and pin 15 are connected to ground. Other things to check are whether...
... That is interesting. I have rev C but no connectivity between pin 11 and pin 15. I've jumped the two together now. ... Changing the baud rate in microcom...
... Perhaps a manufacturing defect? It is not something that I would easily detect, since that buffer of the Max232 is not used (i.e. pin 14 is NC.) ... ...
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