I started playing with Espressif processors with the ESP8266, and quickly moved to the ESP32. The main module I have been using is the ESP32-WROOM-32. Using a module avoid having to mess with RF directly, and makes it a lot easier.
However, I have now discovered the new ESP32-PICO-MINI-02 module.
It is quite impressive.
- It is smaller, half the size of the ESP32-WROOM-32.
- It has more flash (8MB not 4MB, though WROOM modules can have more).
- It has SPI RAM (2MB) so a total of 2½MB RAM rather than just ½MB. Impressive.
- It cannot be hand soldered as pads underneath the module.
- Did I say it was tiny?
How is it so small? Well, unlike the ESP32-WROOM-32, which is several devices in the module (the processor and a flash), it is all one chip. They have integrated the flash and SPI RAM all in one device.
So, armed with this impressive new chip, I have been playing around with my various designs. Re-designing a board to use this is simple at the schematic level, but more of a challenge when it comes to layout. The good news is I am better at layout now, and doing a board a second time is easier, so I have managed to make all my various designs much smaller. This is quite helpful for things like the alarm system controller which has to fit in an EXIT button back box, and can be a squeeze, or even the Galaxy keypad controller than fits in a small gap in the case.
I have taken the chance to tidy up my designs a bit as well, lower power when not using USB, by turning off the USB controller, etc.
I have also designed to make some more boards - including a small generic module, using this:-
This provides 10 GPIO pins, but is a tiny board. I've also made a GPS board.
I was obviously a bit worried about a new module - did I read the data sheet right? Can I solder it (using solder paste) properly? Well I am pleased to say, it worked first time. Yay!
Update: The GPS module works as well. It is fun as has a few GPIOs not normally on the WROOM module (7, 8, and 20). It is worth noting that it uses an ESP32-PICO-V3-02 chip, the V3 and 02 all make slight differences, so worth checking data sheets carefully.