While i love Breadboards and Devboards - sometimes they are just too flaky, too impractical to install in my semi-useful Projects. Always doing full custom boards is too much of a hassle. Sometimes its ok to fiddle on permanent USB on a Bradboard to test something, somtimes i need the MCU hooked to Solar and LIPO.
So i decoupled the MCU section (ESP32/Wifi/BT in that case) from the "mount". The "mount" can deliver Power or extend IO Pins and give further connectivity options.
For the adapter i choose the M.2(E Key)/NGFF Formfactor.
It really also makes the design of a new MCU board a breeze. I just did one for a smaller MCU within 2 hours.
The little module is using 22x30mm M.2 Format. The first "USB mount" is just 52x25, USB/TTL chip, PWR converter etc.
With the "ESPerimeter board" i built another "mount" pilot that adopts straight into a Breadboard.
You power it with USB, program ESP and tinker on the breadboard. SNAPZZ the
1. Moved to "SNAPZZ Bus gen.2". Essentially it's able to take all IO from an ESP32-S2 or Raspberry PICO 2040
2. I reduced to 2 Modules for now:
2.1 ESP32-S2FR based (ESP32-S2 with integrated Flash and RAM)
2.2 Raspberry 2040 Chip (i have 10 samples)
I have the PCBs, the components and the motivation. After Easter break i will
- build some prototypes for both SNAPZZ Module (ESP32 and RP2040 based) - build some prototypes for 2 Launchpads: the ESPIrimenter Breadboard adapter and the USB/40 IO adapter (Pictures in the other Project)
I got a new Microscope as well - good bye my little cheapo USB Microscope, and thanks for all the fish, and welcome KERN Stereo microscope :)
If the Prototypes work as expected i build some 10 Pilot boards and give them away for free to interested people.
Initially the SNAPZZ Modules are 22x30mm. By extending the Chip Family i can get rid of the Flash chip and get plenty more PCB space.
This lead me to making a new size - 22x22mm. To stay compatible with the original base (mount) with 30mm lenghts i added a breakaway section. So it can be mounted in a 30mm length mount, but also in a 22mm lenghts one.
This specific board is using Espressif ESP32-pico-v3-02 Chip. It contains both Flash (2M) and RAM (4M) in the Chip. Another name thing here is the -PRO Suffix. Essentially telling that it contains the EEPROM Chip (U2)
In addition to the "SNAPZZ magnetic" Experiment i am looking into mechanical Lock/Release Systems. I found this tiny nice one that i can use. For ver permanent Installations, a Solder-standoff and a screw is the better choice; For Experimenting, debugging, swapping a Quick-Release Model is better.
The Module itself doesn't need a change, the Notch on Top can stay there and swapped into a Carrier board with a Screw. The Carrier Module (depending on the Quick Lock).
Originally M.2 modules are screwed down (M2, M2.5) to a standoff soldered to the carrier PCB.
To remove the Module you unscrew the little screw, module pops up and you remove it.
For prototyping this sometimes is annoying so i was experimenting a bit with a magnetic lock. I use a small Neodym magnet and glued it to the carrier PCB. the other Magnet sits in the little recess in the module. Those magnets, yet very small (1.5mm high, 2mm diameter) are surprisingly strong once they make contact.
Manufacturability is probably low, as they cannot be soldered. Neodym Magnets have a Curie Temp of ~80 degrees Celsius. Around and beyond this Temperature the Magnets looses it's magnetism permanently.
Thanks for your comment. As an experiment i tried to handsolder (dragsolder) an M.2 connector; lots of Flux and and it works 100% well. But knowing newbies may struggle here. So i started last week to create a universal M.2 adapter PCB with castellated connects. I did some comparisons and found that exactly for this kind of users you need somewhat of a 2mm pitch to make it really easy for hand soldering - which for 79 pins gives me a ~45x45mm PCB. For my modules that's overkill as i dont use all pins, so there will be a "smaller version" as well plus the 1:1 model.