Why would I need this module?
- I want to be able to upgrade/downgrade or use another MCU later in my project.
- I want to be able to recover the MCU when my motherboard is no longer useful.
- I want to be able to debug and program, but I don't want to sacrifice board space for it.
- I don't want to design the same ESP32-peripheral circuitry over and over again.
- I want to get rid of the Chinese development boards with all their flaws. (unreadable/lacking pin numbers, doesn't fit in breadboard, no capacitor on reset pin, large sleep currents, etc...).
- I like the concept of modularity. Others can easily reuse my design.
- I want to build this in a housing an add my own proper (dipole) wifi antenna (e.g. LSR 001-0012).
ESP32 mini module
- Designed for the ESP32-WROOM-32UE (4MB) (only €2.21 on Digikey)
- on 2x 2x15p 1.27mm straight SMD headers : AliExpress (€0.22/pce).
- The ESP32-WROOM only has 28 usable non-GND pins.
- That's a total of 60pins for the mini module. Half of them will be used as GND pins.
- Not opting for THR-headers because of PCB-fabrication limitations: minimum annular ring and clearance of 1.27mm spaced holes.
- Opting for dual row because that's more popular on AliExpress.
- minimal features :
- ✓power supply decoupling
- ✓RC-connection on EN-pin (=RST pin) (to avoid the firmware uploading problem of the NodeMCU-32s)
- Nice to have :
- Has 2x 2x15p 1.27mm straight SMD sockets on top: AliExpress (€0.50/pce)
- Has the necessary pin labels for all ESP32 mini module pins.
- Has a right angled header, so that it can be connected to breadboard using Adafruit's IDC BREAKOUT HELPER. The board would then be at a 90° angle to the breadboard, which also makes the bottom side accessible for measuring. No breadboard pin rows will be covered (and be rendered useless).
- Another option is to solder a 90° 40pins socket on experimenter board. This will put the ESP32 parallel to the experimenter board, which requires less build height.
- The shrouded header allows for easier identification of pin 1.