I have created a schematic and finished the pcb layout - and now I need to renumber the components to match the original schematic so my client can keep track of things. In the kicad documentation it says;
“In KiCad, reference designators consist of a letter indicating the type of component (R for resistor, C for capacitor, U for IC, etc.) followed by a number. If the symbol has multiple units then the reference designator will also have a trailing letter indicating the unit.”
If I add a letter to the end of any component number - I get a “Schematic must be fully annotated” message when trying to update the PCB, and can no longer properly update the schematic, but if I use a letter and then number it works? What am I missing here - is the documentation just wrong or am I doing something wrong?
Using a letter at the end of a symbol denotes that symbol is part of a footprint. Eg a LM324 is a five part symbol (4 op amps and the power) with one footprint.
Updating the Schematic with a footprint finishing with a letter is trying to tell the symbol that it has more than one part. This is not allowed.
In KiCad, single components are given a reference designator of the form letter-number.
A letter-number-letter reference designator, like “U1A”, indicates that the symbol is part of a multi-part component. For example, a TTL 7400 quad two-input NAND gate has four independent NAND gates with suffixes A, B, C, and D (and maybe E for the power connections). All of the parts of a symbol should (must?) be represented somewhere on the schematic and annotated appropriately.
If you explain what designators the original schematic uses, we’ll be better able to suggest solutions to your problem.
OK, now I understand - yes I am renumbering it to match a schematic created in another program, the original had one coupling cap on each ic and the new one we want two, so I numbered them C1a, C1b - and that is causing the error.
Other problem seems to be when I renumber them I have to place them back into position, which is a huge hassle since the layout has already been done…seems there is nothing I can do but redo a lot of the layout again, or is there some option to keep them in the same position I am missing?
I do not understand what you wanted to express.
I have never treat references as having to have one letter + number but as having a letter sequence + number.
From your example it looks that numbers(or digits) inside letter sequence are also allowed.
It sounds to me like multiple leading letters are allowed. (many schematics label diodes “CR” for example.) Maybe it is allowed to have letters in some midpoint in the reference designation. But except for units within one footprint, letters are not allowed at the end. Do I get it correctly?
Piotr doesn’t understand and it’s exacerbated by his use of a translator.
Of course multiple letters at the beginning are allowed. I use JP all the time for example. If you tack 1B after it it becomes unit B of JP1. But if you tack on 1B02 then it becomes instance 1B02 of type JP. That’s the surprising bit.
Generally I use 201 and 301 for the channels of stereo amps for example, rather than use a suffix. But OP is constrained by an existing circuit.
Edit: Other multiple letter symbols I use include: Capacitor Polarized, Resistor Network, Resistor Variable, and Test Point. Not much use for LoudSpeaker on PCBs, but I might get to use BuZzer one day. So it’s not just Resistors, Capacitors, Linductors, Quansistors, and Untegrated circults in my schematics.
A fun fact is that units can be displayed as .2 or _2 instead of B, selected in schematic setup. Obviously the separator between the numbers is needed.
Sorry once again for the late reply…forum requiring me to wait one hour before reposting still - @retiredfeline had replied so quickly that I had the problem solved, was finished working on the pcb and had already moved onto something else before the hour was up!
Really appreciate the quick replies and help - have figured out what I was doing wrong and how things work with the numbering now. Hopefully soon I can reply a bit quicker…have another issue I will create a new post on.
