Does anyone have a definitive answer as to what I need to hook up an E3 to a PC serial port?
The various opinions I've seen so far are:
* If you just wire it up, it may work, but you run some risk of frying the UART in the E3.
* If you just wire it up, it won't work, because you need to invert the signal levels.
* You can wire it up to an E2 line level converter and it will work.
Which one of these, if any, is right?
On Tue, Feb 21, 2006 at 06:05:13PM +0000, David Given wrote:
Does anyone have a definitive answer as to what I need to hook up an E3 to a PC serial port?
The various opinions I've seen so far are:
- If you just wire it up, it may work, but you run some risk of frying the
UART in the E3.
True; I have mine wired up at present with no converter or level shifter.
- If you just wire it up, it won't work, because you need to invert
the signal levels.
- You can wire it up to an E2 line level converter and it will work.
True if taken together I believe; you need an E2 style converter plus an inverter.
J.
I'm using the cable from an old serial digital camera that I have. I guess I struck lucky there. I don't think it has any electronics in it, as neither end looks big enough to contain any.
On 2/21/06, Jonathan McDowell noodles@earth.li wrote:
On Tue, Feb 21, 2006 at 06:05:13PM +0000, David Given wrote:
Does anyone have a definitive answer as to what I need to hook up an E3 to a PC serial port?
The various opinions I've seen so far are:
- If you just wire it up, it may work, but you run some risk of frying the
UART in the E3.
True; I have mine wired up at present with no converter or level shifter.
- If you just wire it up, it won't work, because you need to invert
the signal levels.
- You can wire it up to an E2 line level converter and it will work.
True if taken together I believe; you need an E2 style converter plus an inverter.
J.
-- noodles is good in nagahama
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On Tuesday 21 February 2006 18:08, Jonathan McDowell wrote: [...]
- If you just wire it up, it may work, but you run some risk of frying
the UART in the E3.
True; I have mine wired up at present with no converter or level shifter.
Hmm.
[...]
- You can wire it up to an E2 line level converter and it will work.
True if taken together I believe; you need an E2 style converter plus an inverter.
If I were to wire it up to an E2 converter *backwards* --- so that logic 0 was -5V and logic 1 was 0V --- would the tolerances in the E3's UART and the converter's own chip make it work? After all, if the E3 can cope with +/- 25V for RS232, it ought to be tough enough to manage -5V...
-
David Given -
J. Snell -
Jonathan McDowell