ESP32 - FIRST STEPS
Tomer Weller / 2016-11-28
Note: a revised version of this post has been uploaded to my blog.
ESP - IDF
ESP32 ARDUINO CORE
Ring Oscillator benchmark
ESP32, successor to the beloved ESP8266, is system on a chip (SoC) that can do everything:
Espressif, the manufacturer, have been kind enough to send some units of their new ESP32 modules for evaluation. (huge thanks to John Lee @EspressifSystem) This posts explores basic connectivity, different ways to program it and basic benchmarking.
Note: soldering the module to the breakout board proved non-trivial, the ground plane is very large so a high wattage soldering iron is recommended for soldering the ground pads.
⇒ miniterm.py /dev/tty.usbserial-XXXXXXXX 115200
ets Jun 8 2016 00:22:57
rst:0x1 (POWERON_RESET),boot:0x13 (SPI_FAST_FLASH_BOOT)
IDF version : master(db93bceb)
WIFI LIB version : master(934d079b)
ssc version : master(r283 4d376412)
mode : softAP(26:0a:c4:00:27:f4)
dhcp server start:(ip: 192.168.4.1, mask: 255.255.255.0, gw: 192.168.4.1)
Not only does it work, it even defaults to opening a public access point
⇒ airport -s | grep ESP
ESP_0027F4 26:0a:c4:00:27:f4 -14 1,+1 Y -- NONE
When a device enters the network:
n:1 0, o:1 0, ap:1 1, sta:255 255, prof:1
station: 80:e6:50:27:b6:62 join, AID = 1, g, 20
I couldn't find any other interesting things in oem firmware.
In case you were wondering, like me, wether ESP8266's AT command-set works in this prompt, the answer is no. It's not very clear what commands work in this prompt.
Before programming this chip it's crucial to understand that, unlike other embedded systems, the ESP32 comes with a light operating system - FreeRTOS. The following methods to program this chip don't replace the FreeRTOS firmware, but rather deploy applications for it to run. I imagine that in the near future we'll see other operating systems or no-os approaches for reprogramming these chips.
Espressif IoT Development Framework is a set of open source libraries and tools to facilitate deployment of apps to ESP32s FreeRTOS.
Espressif have also been hard at work to get the maker community happy and makers love Arduino. The ESP32 arduino core integrates ESP-IDF deeply into the arduino tools. This includes providing a WiFi api that is almost 100% compatible with existing wifi shields for arduino.
Note: currently, to take advantage of the dual core setup - IDF is the way to go.
ESP32 Arduino Core
Note: These tests only occupy one core. The second core is free to perform other tasks, mostly networking. Example: https://github.com/tomerweller/esp32-rtos-webclient/tree/with-ring-oscillator
ESP32 Data Sheet
ESP-WROOM32 Data Sheet
ESP32 official forum
ESP32 Getting started (hackaday)