[Elecraft] Troubleshooting KIO2

[David Woolley]

It's going to be similar to the application circuit in section 7.1 of 
<https://ftdichip.com/wp-content/uploads/2020/08/DS_FT232R.pdf>, except 
that not all the wires may be connected, and, in particular, any that 
conflict with the K2's use of a pin on the connector for Auxbus won't be 
connected.  (The KIO2 documentation will tell you which pins are 
actually used in a standard way.)

It's just possible that they have left out the level convertors, as it 
would probably work without them.

Assuming it has the level convertors, the standard tool for looking at 
what is happening will be something like this: 
<https://czh-labs.com/products/czh-labs-rs232-led-link-tester-module-db9-male-to-db9-female> 
(picked at random from a Google search.  If it doesn't have level 
convertors, the LEDs may only light up for one state, of the nominally 
bipolar signal.  (If auxbus is on one of the monitored pins, it might be 
disrupted, but the resistor on the LED should ensure that there is no 
permanent damage.  It would be better to do it on the end of the 
official KIO2 to RS232 cable, though.

Incidentally the S in USB stands for serial, but it is different, and 
much more complex, serial protocol.

Also, I found the price eye watering, given what is probably in it; the 
problem with very low production run products.  Things like Arduino 
throw in all but the level convertors and DB9 connectors, as just part 
of something that sells for under GBP 10, although current Arduinos use 
an AtMega microcontroller chip, rather than the FTDI chip.

Before considering alternatives, do beware of the the vulnerable, 
Auxbus, signal on the non-standard K2 connector.

My PC motherboard was selected because it had a real RS232C asynchronous 
port.

-- 
David Woolley
Owner K2 06123

On 27/05/2022 20:41, Dave Sublette wrote:
> It would be nice to have a schematic of the KUSB cable.
> 
> If anyone has experience troubleshooting this sort of thing or knows where
> to get more information, please let me know.