Having sorted (to a degree) I have now problem with “connection error” in the Electrical Rules Checker.
I have the output from a BCD-Decimal converter with “open collector” outputs connected to the Nixie cathode marked as “input” and the ERC comes back with “Error: input pin not driven by any output pins”. I have 6 Nixie tubes with 10 inputs each so I am getting 60 errors
Surely an “open collector” is an output and the cathode of the Nixie is and “input”?
Do have marked the “open collector” with a “power flag” or what I need to do?
Thank you for the constant inputs from the forum members. TIA
These “Input” and “Output” types are meant for digital logic. An “open collector” is no “proper” output because it can not generate an active high output. Neither is a Nixie tube pin an “input” in terms of digital logic.
ERC has limited use, and it does not work very well with analog electronics, and the usual approach is to not even try. For the majority of transistors (both BJT and FET) for example have all their pins set to “passive” even though they are active elements.
While browsing through KiCad’s libraries I find there are quite a lot of FET’s that have their gate set to “input”. (maybe 30% or so of them?) I’m not really sure if that is correct. I guess it mostly leads to nuisances to fix DRC while it has little benefit. ERC is a bit of a simple minded tool, and it’s a bit of a balance to make it useful without having it generate too many senseless warnings and errors.
