Storage Options for ESP32
Thought for 1 min 29 sec
Yes.
- Removable storage: A microSD card socket U4 is on the schematic (Molex 0472192001). It’s wired to the ESP32 via SDIO (CLK/CMD/DAT0–3), so you can use a microSD card for files/logs.
- On‑module storage: The ESP32 module U1 is ESP32-S3-WROOM-1-N8R8; per its datasheet this variant includes 8 MB Quad SPI flash (plus 8 MB PSRAM), which can store firmware and limited data.
Do you plan to log primarily to microSD, or also use internal flash for smaller datasets?
Thought for 1 min 20 sec
Great idea—yes, you can replace the microSD socket U4 with an external SPI NAND device for solid-state storage.
First, a quick clarification
- Do you mean 8 GB (gigabytes) or 8 Gb (gigabits = 1 GB)? SPI NAND commonly tops out in the multi‑Gb range per die; true 8 GB is typically done with eMMC.
Two practical paths
- SPI NAND (data storage, 3.3V preferred)
- Interface: Use CS#, CLK, IO0–IO3 (QSPI). Avoid ESP32 boot-strap pins.
- Power: Run from 3.3V to avoid level shifting. If the part is 1.8V-only, add a 1.8V LDO and level translators.
- Termination: Add series termination resistors of 22Ω–33Ω (at minimum on CLK; also consider D0–D3 if edges are too fast).
- Decoupling: 0.1 µF at each VCC pin plus a local 4.7–10 µF bulk nearby.
- Pins to tie: WP#/HOLD# (if present) per the datasheet (pull-ups or tie-offs). Terminate all unused pins per their datasheet.
- Layout: Keep CLK and D0–D3 short and length-matched, solid ground reference, minimize vias.
- Firmware: Plan for NAND specifics (bad blocks, ECC, wear leveling). Use a driver/FTL that handles these.
- If you truly need 8 GB managed storage
- Use eMMC instead of SPI NAND. It reuses the SDMMC host you wired to [U4], provides on-die ECC/FTL/wear leveling, and is much simpler in firmware. Requires a fine‑pitch BGA footprint and typically supports 1.8V signaling.
Suggested next step
- Confirm capacity: 8 GB vs 8 Gb.
- Confirm voltage domain: stick with 3.3V only, or is a new 1.8V rail acceptable?
Once you confirm, I’ll propose specific, in-library parts (SPI NAND or eMMC) and show exactly how to rewire the nets formerly used by [U4].
