finally got my esp32 ... some test results and conclusion

[hoek67]

Had 2 ESP8266's given to me some time back and finally got to experiment with them. Not bad little units but the SRAM got eaten a bit and since the ESP32 was available... IMO makes the ESP8266 redundant if wanting some RAM and extra CPU cycles. In defence of the ESP8266 it still had 40K+ of SRAM left which is still a LOT more than many other boards have in total.

Got the ESP32 DEVKIT V1 DOIT variety and compiled the blink sketch... worked well.

Added some routines to my main library so the ESP32 is supported and started connecting a few devices to test.

Got my SSD1305 128*64 OLED connected and working over SPI and my PCM sound library is now decoding and playing MP3's happily (Helix fixed point decoder).

Had to adjust my timer library a bit to put a small wrapper around the ESP32 timer routines but finally got it working. Seems every MCU has different timer routines for doing... basically the same thing.

The 2 8 bit DAC's work better than expected and routing through a small mini-amp gives very good audio.

The OLED also refreshes > 100 fps while decoding and playing a memory embedded MP3 easily.

After compiling a basic sketch with MP3/PCM support (~8K in static buffers) gives ~307K for usable RAM and ~1MB of FLASH still available.

This ESP32 is ticking a lot of boxes :-

1) RAM - heaps compared to all other offerings
2) Programming space - heaps! 1MB left after including large library
3) Efficient SPI - Use SPI a LOT for OLED displays and sensors so a good library is essential
4) Pins - Nice simple layout and breadboard friendly (compare to Arduino boards with their weird spacing)
5) WiFi - Works great... added bonus
6) DAC - 2 working DAC's that are able to be called from interrupt and thus can be used for fast and efficient sound output
7) Price!!!!! - Got mine off Ebay Australia for A$12 delivered as didn't want to wait for OS delivery. Aliexpress sells a lot for $7-$15 which is amazing given what the device is capable of.

All up... a great little board.

10+ extra digital pins would be great... especially if enough so 8 bit parallel devices could be used.

I hope to get my video playback working and when I do will put a small youtube video up showing it. Arduino Due with 96K SRAM and 84Mhz clock can so this should do it easy.

Made a decision last week because of all the cheap and powerful 32 bit MCU's to take out support for AVR and other 8 bit boards from my library.

Well done ESP32 team on a great little device!