AXE401 and 100K resistor

vk6bgn

New Member
Hello All,

Just received my AXE401 project board from a local supplier here in Australia. Looks really awesome! Looking at the AXE401 manual tonight, I noticed there is a 100K resistor from RXD, physical pin #6 to earth. I've not seen this or used this in any projects I've built. Is this to keep RXD from "floating" if the links for "H2" RXD and "H3" TXD are moved to S.0(C.7) and S.1(C.6)? Just curious.


"HamRadioAddict"
 

nick12ab

Senior Member
Is this to keep RXD from "floating" if the links for "H2" RXD and "H3" TXD are moved to S.0(C.7) and S.1(C.6)? Just curious.
Yes, because when H2 is removed the pull-down resistor in the download circuit is no longer connected to the pin so a pull-down is needed to prevent unreliable operation.

The value is high so that it does not interfere with proper operation of the download circuit.
 

westaust55

Moderator
@HRA,
Are you still using PE version 5.2.9 as per your current "signature"
As the PE is now up to version 5.5.6 resolving a few bugs and some add-ins
 
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