ESP32: Getting to know, writing and launching the first firmware

Hello. A few days ago I got a copy of the ESP32 Demo Board V2, which I immediately happily announced at my FB. Of course, it’s not very easy to get it now: the first batch (600 pieces), which went on sale at Seeed Studio, was scattered in a matter of hours!



But as a developer and hardware integrator of the Open-Source library for Blynk, I often get early access to various devices. Blynk allows you to quickly prototype and build iOS / Android Apps for the Internet of Things using drag'n'drop blocks right on your phone.

The fee, which fell into my hands, looks like this:
')


ESP32 promises to make a revolution in the IoT world again , as its younger brother ESP8266 did in due time (and I sincerely hope that it will be so). If you have not heard anything about ESP8266 before - read, for example, here and here (and Google).

What is the new ESP32? Even at first glance, it is clear that this is a very powerful platform. For example, Ivan Grokhotkov (developer of Arduino support for ESP8266) published a photo of the game DOOM on ESP32:

ESP32 specifications

CPU: Xtensa Dual-Core 32-bit LX6, 160 MHz or 240 MHz (up to 600 DMIPS)
Memory: 520 KByte SRAM, 448 KByte ROM
Flash on the module: 1, 2, 4 ... 64 MB
Wireless:

• Wi-Fi: 802.11b / g / n / e / i, up to 150 Mbps with HT40
• Bluetooth: v4.2 BR / EDR and BLE

Peripheral interfaces:

• 12-bit SAR ADC up to 18 channels
• 2 × 8-bit DAC
• 10 × touch sensors
• Temperature sensor
• 4 × SPI
• 2 × I²S
• 2 × I²C
• 3 × UART
• 1 host (SD / eMMC / SDIO)
• 1 slave (SDIO / SPI)
• Ethernet MAC with DMA and IEEE 1588 support
• CAN 2.0
• IR (TX / RX)
• Motor pwm
• LED PWM up to 16 channels
• Hall sensor
• Ultra low power analog pre-amplifier

Security:

• IEEE 802.11 security WFA, WPA / WPA2 and WAPI
• Secure boot
• Flash encryption
• 1024-bit OTP, including up to 768-bit per task
• Cryptographic engine: AES, SHA-2, RSA, ECC, RNG

In the picture it looks like this:


More detailed (and almost complete) information is on off. Espressif Systems website . ESP32 will be available (at least) in several forms:

» ESP-WROOM-32 module ($ 5?)



Pinout | Datasheet

» Module AI-Thinker ESP3212 , similar to the ESP-12F ($ 6.9). On the ESP3212 no legs for SD-card, in contrast to the WROOM-32.



Eagle Library | KiCAD Library

Chip ESP32-D0WDQ6 ($ 2.8?) | Datasheet

• D : Dual-core
• 0 : No internal flash
• W : Wi-Fi
• D : Dual-mode Bluetooth
• Q : Quad Flat No-leads (QFN) package
• 6 : 6 mm × 6 mm package body size

It is worth noting that before the ESP32 release, the ESP31B (test version) was available as an Espressif ESP-WROOM-03 module, and on the Internet it is often confused with ESP32.

Caution! Almost all references to ESP32 until 09.2016 is actually about ESP31B, which is not the same at all.

Setting up the development environment

On the offsite now you can find links to two SDKs:

» ESP31_RTOS_SDK - SDK for ESP31B, built on FreeRTOS.
» Espressif IDF (IoT Development Framework) - Official development framework for ESP32.

Although it is not obvious from the description on the site, only ESP-IDF is suitable for the release version. There are installation instructions for linux , windows , macos .

I have 64-bit Ubuntu Linux. First downloaded the compiler:

sudo mkdir /opt/Espressif sudo chmod a+rw /opt/Espressif cd /opt/Espressif wget https://dl.espressif.com/dl/xtensa-esp32-elf-linux64-1.22.0-59.tar.gz tar -xzf xtensa-esp32-elf-linux64-1.22.0-59.tar.gz 

The xtensa-esp32-elf folder should appear. Then I downloaded esp-idf (in the same /opt/Espressif folder):

 git clone --recursive https://github.com/espressif/esp-idf.git 

A folder esp-idf should appear.

Writing Hello World

Espressif has prepared a template for us, so it's very easy to start:

 cd ~ git clone https://github.com/espressif/esp-idf-template.git myapp cd myapp 

You can try to run a pure template, but it seemed uninteresting to me. I added a little main/app_main.c to flash the LED. That's what happened.

We collect and fill the board

To build a project, you first need to configure the environment

 cd ~/myapp export PATH=/opt/Espressif/xtensa-esp32-elf/bin:$PATH export IDF_PATH=/opt/Espressif/esp-idf 

Now we connect the board, turn on the power, and look at which port it appeared (I have this / dev / ttyUSB3). Run the configurator:

 make menuconfig 

You need to go to the "Serial flasher config" and install the "Default serial port" on the port of the board. You can still see other settings.
All save and exit.

Compile:

 make 

If everything is good, fill in the fee:

 make flash 

Connect to the board using Putty (screen, or another terminal emulator). We distort the power, and see:

 [213450] low [1212827] high [2212827] low [3212828] high [4212828] low 

If you connect the LED to the IO18 , it also flashes. So our code works!

Debugging

Another good news is that ESP32 has a JTAG interface on IO12, IO13, IO14, IO15 . I will try to use it for debugging programs. But about this in the next article.

Well, it remains only to wait for the availability of ESP32 in stores, stabilization of the SDK (I hope it will initially be much more stable than ESP8266). Bluetooth is also not available yet. Soon (according to my data, very soon), beta support for the Arduino IDE and MicroPython should appear, then Espruino and something similar to NodeMCU.

What do you think?