Artificial Intelligence Response
Direct answer to the question
If by “DS3231 AT24C32 IIC RTC Module footprint” you mean the common Arduino-style module board (often the blue ZS-042 type), the practical PCB footprint is usually not the bare DS3231 IC footprint. You normally treat it as a 6-pin, 2.54 mm pitch module/header, with a mechanical outline of about 38 mm × 22 mm and roughly 14 mm height including the battery holder. (stacktronics.com)
So, in most CAD designs, use:
- Electrical footprint:
PinHeader_1x06_P2.54mm
- Mechanical outline: custom courtyard / keepout for about 38 × 22 mm
- Optional 3D/mechanical model: community library model, but verify it manually before fabrication because some downloadable module footprints are community-generated rather than vendor-authoritative. (snapeda.com)
If instead you mean the DS3231 chip itself, the DS3231 is supplied as a 16-pin, 300-mil SO package. (analog.com)
Detailed problem analysis
The term “footprint” is ambiguous here, because there are two very different design cases:
- You are mounting the ready-made RTC module onto your PCB
- You are designing your own PCB using the DS3231 IC and AT24C32 EEPROM
These require different footprints.
1) Footprint for the ready-made module
For the common DS3231 + AT24C32 module, the most robust approach is to treat it as a plug-in submodule:
- The module commonly has a single 6-pin header
- The header pitch is 2.54 mm
- The board size is commonly around 38 × 22 mm
- The common exposed pins are the RTC-related signals and power pins. (stacktronics.com)
A practical footprint is therefore:
- 1 row, 6 through-hole pads
- Pitch: 2.54 mm
- Pad X coordinates: 0, 2.54, 5.08, 7.62, 10.16, 12.70 mm
- Recommended drill: about 1.0 mm
- Recommended pad diameter: about 1.7 to 1.9 mm
Those drill/pad sizes are engineering recommendations for ordinary 0.64 mm square header pins.
2) Mechanical footprint versus electrical footprint
For modules like this, the electrical footprint and mechanical footprint are different concepts:
- Electrical footprint = just the 6 holes for the header
- Mechanical footprint = board outline, battery-holder clearance, solder-joint clearance, and possible mounting hole(s)
If you only need connectivity, a standard 1x6 2.54 mm header footprint is sufficient.
If you need enclosure fit, assembly collision checks, or a professional PCB drawing, add:
- module outline on F.Fab / Dwgs.User
- courtyard or keepout around the coin-cell holder
- bottom-side copper keepout if the module sits flush over your board
This is important because the coin-cell holder and through-hole solder joints on these modules can protrude significantly.
3) Pin order
A common published pin sequence for the 6-pin header is:
However, many sellers list the same six signals in the reverse reading direction, for example:
This is not necessarily a contradiction; it is often just a matter of which end of the header you start reading from. The engineering rule is:
- Do not trust a generic internet footprint blindly
- Verify your exact module’s silkscreen and actual pin order with a meter or calipers before ordering boards
4) If you mean the bare IC footprint instead of the module
If your goal is to design a custom RTC board rather than mount the module, then the module footprint is the wrong target.
In that case:
- DS3231 IC: 16-pin, 300-mil SO package (analog.com)
- AT24C32 EEPROM: package depends on the exact suffix/vendor part you buy, so the EEPROM footprint must be taken from the exact AT24C32 datasheet for that ordering code
For a custom PCB, this is generally the better engineering solution than embedding a low-cost breakout module, because it gives:
- better BOM control
- better DFM/assembly consistency
- lower height
- cleaner EMC/layout
- clearer battery-domain control
Current information and trends
At present, there are community CAD resources for this module class:
- SnapMagic/SnapEDA lists a module entry for the DS3231 AT24C32 board and offers downloadable symbol/footprint assets, but explicitly warns that the footprint was not created by SnapMagic, so it must be checked before use. (snapeda.com)
- Flux also has a public module entry for
DS3231-Module, again useful as a starting point rather than as unquestioned production data. (flux.ai)
Current best practice in electronics CAD is:
- use community footprints only for initial placement
- always validate against:
- your exact purchased module
- caliper measurements
- a 1:1 print
- 3D collision check if height matters
That is especially important here because this module is a third-party breakout format, not a tightly standardized JEDEC package.
Supporting explanations and details
Recommended footprint strategy in KiCad / Altium / Eagle
Option A — simplest and recommended
Use only a standard header footprint:
PinHeader_1x06_P2.54mm_Vertical- or matching female socket footprint if the module plugs in
This is the best choice when:
- you want easy replacement
- you may buy modules from different sellers
- you do not need tight mechanical registration
Option B — full custom module footprint
Create a custom footprint containing:
- 6 plated through-holes at 2.54 mm pitch
- board outline about 38 × 22 mm
- silkscreen reference for pin 1
- top/bottom keepout under the module body
- optional 3D STEP model association
This is useful when:
- you need exact board placement
- you are stacking several modules
- enclosure clearance is tight
Example pad layout for a custom PCB footprint
You can start with this electrical pattern:
- Pad 1: \(x=0.00\), \(y=0.00\)
- Pad 2: \(x=2.54\), \(y=0.00\)
- Pad 3: \(x=5.08\), \(y=0.00\)
- Pad 4: \(x=7.62\), \(y=0.00\)
- Pad 5: \(x=10.16\), \(y=0.00\)
- Pad 6: \(x=12.70\), \(y=0.00\)
Recommended fabrication parameters:
- Drill: \(1.0\text{ mm}\)
- Pad diameter: \(1.7\text{ to }1.9\text{ mm}\)
- Pin 1 shape: rectangular
- Others: circular
This is a good footprint for normal 0.1-inch header pins.
Why a generic 1x6 header is often better than a “module footprint”
Because the module is already a PCB assembly, your main board usually only needs a mating interface. Using a generic header/socket gives you:
- replacement flexibility
- tolerance to seller-to-seller dimension variation
- lower risk if the module revision changes
Ethical and legal aspects
There are no major legal constraints in using this module in a hobby or prototype design, but there are practical safety issues:
- Some common DS3231 module variants include a charge path intended for rechargeable LIR2032 cells; if your board is populated with a primary CR2032 and powered from 5 V, inspect that board revision carefully before use. (hackaday.io)
- For professional products, using anonymous clone modules can create:
- traceability issues
- inconsistent mechanical dimensions
- uncertain long-term sourcing
- uncertain battery-domain implementation
For commercial hardware, designing around the bare DS3231 IC is usually the safer engineering route.
Practical guidelines
Best implementation method
If you are making a carrier PCB:
- Use standard 1x6 2.54 mm female header footprint
- Add a mechanical keepout of at least the module body area
- Do a 1:1 paper print test before manufacturing
Best practices
- Measure the actual module with calipers
- Check the pin order from the silkscreen, not from memory
- Leave clearance under the battery holder and solder joints
- If using community CAD files, compare them against the physical module
Potential challenges
- Seller-to-seller module differences
- reversed pin numbering conventions in online drawings
- battery holder interference
- hidden underside protrusions
- non-authoritative third-party footprints
How to verify before fabrication
- Print the PCB 1:1 on paper
- Place the real module on the print
- Confirm all six pins align
- Confirm no battery holder or solder joint collides with nearby parts
- If possible, import a STEP model and inspect height/clearance
Possible disclaimers or additional notes
- The module footprint is not a formal industry-standard package in the way SOIC, QFN, or TSSOP are.
- Online module CAD libraries are useful, but several are clearly community-generated and should be treated as draft references, not production truth. (snapeda.com)
- If you are designing for production, the better solution is usually to place:
- the DS3231 IC directly
- the exact EEPROM package you selected
- your own battery holder and backup-power network
Suggestions for further research
You may want to confirm one of these next:
- Exact CAD software: KiCad, Altium, Eagle, EasyEDA, etc.
- Exact module revision: ZS-042 or another clone
- Whether you want a plug-in footprint or a full mechanical footprint
- Whether you actually need the bare DS3231 IC package footprint instead
If you tell me your CAD tool, I can generate:
- a KiCad footprint
- an EasyEDA footprint
- an Altium land pattern
- or a complete symbol + footprint pin mapping
Brief summary
- For the common DS3231 AT24C32 RTC module, the practical PCB footprint is usually a 1x6, 2.54 mm through-hole header, not the bare IC footprint. (stacktronics.com)
- The common module body is about 38 × 22 × 14 mm, so add a mechanical outline/keepout if physical fit matters. (stacktronics.com)
- If you mean the RTC chip itself, the DS3231 is a 16-pin 300-mil SO package. (analog.com)
- Downloadable module footprints exist, but because they are often community-generated, they must be verified against the physical part before fabrication. (snapeda.com)
If you want, I can provide the exact KiCad .kicad_mod footprint for the common 6-pin DS3231 module next.
