Posts Tagged ‘espressif’
Orange Pi Development Boards

A First Look at ESP32-LyraTD-MSC Audio Mic HDK with Baidu DuerOS Assistant

February 18th, 2018 1 comment

Earlier this year, Espressif Systems had unveiled their ESP32-LyraTD-MSC Audio MiC HDK (Hardware Development Kit) which features an ESP32-WROOM module, a 4-mic array DSP, 3 microphones, an audio jack, and various I/Os.

I received the board a couple of weeks ago, and while there’s no public information released yet, the company provided me with ESP32-LyraTD-MSC User Guide in English. Eventually, I’d expect Google Assistant and Amazon Alexa to be supported, but in the meantime I had to leverage my (lowly) Chinese language skills to get started since the kit is pre-loaded with firmware connecting to Baidu DuerOS voice assistant.

ESP32-LyraTD-MSC Unboxing

The kit came in a bland Espressif Systems carton box.

Inside the package, I could only find one kit comprised of two boards.

The bottom board read ESP32_MicrosemiDSP_Mainboard-V1, and does not show much apart from marking for connectors, headers and the power switch.

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While the top comes with eight buttons (Vol +, Vol -, Mode, Boot, RST, Rec, Play, and Set), three microphones, as well as some configuration switches, which you may not want to touch a first…

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We can take the two boards apart to check out the mainboard, and ESP32_MicrosemiDSP_SubBoard_V1 with the microphones and buttons which includes a chip marked “N1309-3216”.

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If we have a closer look at the main board, we’ll find ESP32-WROVER module, MicroSemi ZL38063 audio processor which will process the audio from the microphones, and assist ESP32 with wake word recognition, as well as a CP2102N chip for debugging. We also have a micro SD card slot, two micro USB port (one for power, one for UART), an audio jack to connect a speaker, an on/off switch, and various headers for I/O and debugging (e.g. JTAG).

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Testing Espressif Systems ESP32 Audio Mic HDK with Baidu DuerOS

As this stage there’s actually little you can do due to the lack of documentation, but I was still able to test the hardware with Baidu DuerOS assistant. The first part of the user manual tells you to flash the firmware, but the requested files are nowhere to be found, and luckily the board was pre-loaded with some version of it.

So what I had to do first is to connect a USB power supply to the POWER micro USB port as well as a pair of speakers. If you plan to modify and flash the firmware (once it becomes available) you’ll also need to connect a micro USB to USB cable between your (Windows) computer and the UART micro USB port.

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Now change the power switch to ON, and for the first boot, you should see the blue LED blink. Press the SET button for a few seconds until the board utters something in Chinese (which I could not understand), and install & run IOT Espressif for Android (apk) or ESP-TOUCH for iOS on your smartphone. Skip all the initial steps, and tap on the top left icon, select Add devices, input your WiFi password, and click OK.

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After a few seconds, you should see one item added to the “Connected to WiFi Device List”, meaning the kit is now a client on your WiFi network. The blue LED should now be on at all times (no blinking).

Now we can try the voice assistant with “Alexa” wake word, which will cause the board to reply “您哈! 有什么吩咐“ (nin hao! you shenme fenfu) which translates to “Hello! How can I help you?”. We can then repeat “Alexa” with our request in Chinese.  I tried to ask for the time, and weather, and play music in the video below.

The assistant combines female and kid voices for interaction. I actually added one MP3 and one FLAC audio files in the micro SD card hoping it would start playing them, but instead it started some music from then net.

Microsemi ZL38063 Documentation & Tools

That’s all I could do for now, as we’ll need to get more documentation and some source code from Espressif Systems to further experiment with the platform. Although not compulsory, you may also be interested in ZL38063 audio processor resources since it interfaces with ESP32 over SPI for commands and I2S for audio. It may be necessary to change the wake word for example, although Espressif Systems mentioned they could do that themselves, and they’d just need 5,000 audio samples of the wake/hot word. Most of documentation and software tools are not public, so you’d need to request access to those with a company email address.

To my surprise, I managed to access the files using my website address, but sadly can’t share anything since none of the files are publicly available. The process is somewhat cumbersome, as you need to get approval for the account first which takes a few days, then request access to documentation for another day or two. There’s a separate login for software and registration to “Microsemi Software Delivery System (SDS)” is automatic, but again you need to request access to each software/firmware package individually which in my case was accepted within 24 hours. It would be good if Espressif Systems and/or Microsemi themselves could make it easier for developers to access those resources for a processor that was released in 2015.  Some documentation for ZL38063 based Microsemi AcuEdge Development Kit for Amazon AVS (ZLK38AVS) can be found on Github, but I’m not sure whether much of it is usable for the Espressif development kit.

Espressif Audio Mic HDK is not for sale just yet, but the company has sent the kit to several developers, so we should except some progress in the weeks or months ahead. I’ll likely check it out again once on English voice assistant is made to work, and more resources are made public.

MicroSemi ZL38063 Audio Processor is Designed for Microphone Arrays

February 6th, 2018 6 comments

I’ve already been experimenting with DIY smart speakers and corresponding services for example using ReSpeaker board with Microsoft Bing Speech API, or Orange Pi Zero with Google Assistant SDK. But so far all the hardware platforms I used only came with one microphone, no microphone array that help with wake word detection in noisy environments.

Last week-end, I received Espressif Audio Mic HDK, an ESP32 board with a 3-microphone array which I’ll review a in a few weeks once documentation becomes available and I clear some other items in my review list. In the meantime, I checked out the hardware, and found out the mainboard also comes with Microsemi ZL38063 audio processor specifically designed for microphone array. The chip was released las year, and can be already found in the company’s AcuEdge Development Kit for Amazon AVS, but since I’m going to use a board based on ZL38063 I’d thought to have a closer look to better understand its capabilities.

MicroSemi ZL38063 main features:

  • DSP with voice hardware accelerators
  • Microphone Array Configuration
    • 2-3 microphones linear array for 180° audio pick up
    • 3 microphone off-axis or triangular arrays for 360° audio pick up
    • Device cascading allows up to a 6 microphones array for both 180 & 360° audio pick up
  • Supports 360o sound location estimation
  • Full Narrowband and Wideband Acoustic Echo Cancellation (AEC) operation
  • Noise Reduction
  • Far field microphone processing
  • Two way communication
  • ASR (Automatic Speech Recognition) Assist Algorithms
    • Support microphone configuration listed above
    • Support for Barge-in, or incoming trigger ‘spotting’ in the presence of DAC audio output
    • Enhanced far-field support for distances up to 16 feet (~5 meters) from the microphone.
  • Host interface – I2C or SPI
  • Debugging – Via UART interface
  • Storage – SPI flash
  • Expansion – 14 GPIOs
  • Power Modes – 2 low power modes controlled by reset
  • Packages
    • ZL38063LDF1 – 64-pin QFN (9×9) package (Tape and Reel)
    • ZL38063LDG1 – 64-pin QFN (9×9) package (Tray)
    • ZL38063UGB2 – 56-ball WLCSP (3.1×3.1) package (Tape and Reel)

So basically, the chip process audio from multiple microphone (2 to 6), and detects voice commands. The

ZL38063 Block Diagram – Click to Enlarge

The block diagram also reveals the chip can be connected to speakers, and interface with the host processor over I2S/PCM to send PCM audio, and I2C or SPI for commands. It also supports an optional external SPI flash.

The chip supports Microsemi AcuEdge technology, which consists of license-free, royalty-free intelligent audio IP algorithms, and firmware can be upgraded to support specific mode of operations. The company of provides a reference design, (ZLS38508) MiTuner GUI software to interactively configure ZL38063 device with the following options:

  • Auto Tuning and Subjective Tuning support
  • Provides visual representations of the audio paths with drop-down menus to program parameters, allowing:
    • Control of the audio routing configuration
    • Programming of key blocks in the transmit (Tx) and receive (Rx) audio paths
    • Setting analog and digital gains
  • Configuration parameters allow users to “fine tune” the overall performance

Applications for such chip not only include smart speakers, but also smart home gateways, set-top boxes, digital assistants, basically anything that may require voice commands detection. You’ll find documentation and software on the product page, but most of it is only accessible after registration. It’s free, but you need a company or university email address, and after email confirmation wait for the company to accept your application.

Back to Espressif Audio Mic HDK. Espressif claims keyword recognition runs on the Espressif ESP32 module, so that means the MicroSemi ZL38063 chip does not perform the wake word detection by itself, but instead assists the host processor by processing the audio with specific algorithms that make detection more accurate on the host processor.

Espressif ESP32 LyraTD MSC HDK is Designed for Smart Speakers, Wireless Audio and other Smart Home Appliances

January 16th, 2018 9 comments

[Update February 17, 2018:  The kit was previously referred as ESP32 LyRaTD MS1, but the company appears to have changed the name to ESP32-LyRaTD-MSC]

So apparently voice command will represent 50% of all searches in the next two years, and everybody is jumping on the smart speaker bandwagon, with announcements from many companies at CES 2018, including Google’s Android Things + Assistant products‘ announcement,  NXP i.MX 8M official launch, Amazon Alexa Voice Service (AVS) development kit from Amlogic and Allwinner, and more.

Espressif Systems is about to join the party with their ESP32 LyraTD MS1 HDK (Hardware development kit) that most people will likely remember as “Audio Mic HDK” that was announced on Twitter.

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Espressif Audio Mic HDK specifications:

  • Wireless Module – ESP32-WROVER module with 802.11 b/g/n WiFi and Bluetooth 4.1 LE connectivity.
  • DSP – 4-mic array chip
  • Storage – micro SD card for audio files
  • Audio
    • Audio driver chip
    • Earphone jack
    • Dual speaker output ports
    • 4x microphone array with up to 3 meter sensitivity while playing music
  • Expansion
    • I2C/SPI header
    • 6-pin UART header
    • I2S header
    • Others undocumented
  • Debugging – USB-UART micro USB interface (based on CP2102N), and JTAG header
  • Misc – Power switch, 8x keys on top
  • Power Supply – 5V via micro USB port

The kit can work over WiFi or Bluetooth, supports major cloud voice vendors such as Amazon Alexa, Google Assistant, and Baidu DuerOS. Soft decoder, and hot word recognition runs directly on ESP32 processor.

In twitter, the company also said you could implement your own hotword/keyword, by providing around 5000 unique recordings of your selected word, and that they expect to ship the board next week. It’s unclear when the board will be available for sale however.

One of the commenter mentioned he made his own ESP32 Circle evaluation kit with an audio jack, and a single microphone. If you are interested in that third party board, you can purchase it on Taobao for 169 RMB (~$26). The official Espressif Audio Mic HDK should sell for a bit higher due to the extra features.

ESP32-PICO-KIT v4 Board Based on ESP32-PICO-D4 SiP Now Available for $10

December 7th, 2017 2 comments

A little while ago, I received a bunch of ESP32 PICO Core development boards which were based on Espressif Systems ESP32-PICO-D4 system-in-package with ESP32, 4MB SPI Flash, and other components. The advantage of such chip is that is requires less external component, and allows for smaller designs. For example, the boards I received would leave two row of pin on each side of the board, while most other ESP32 boards will only expose one row on each side.

I used the board to play with Micropython ESP32 port, and later-on when I launched a giveaway of 8 of the boards, I found out the name had changed to ESP32-PICO Kit, with the documentation listing v3 with all pins connected to male headers, and v4 with 6-pin not connected to a male header as shown in the photo below. Both versions of the board also have a different pin layout. But you don’t need to care since AFAIK v3 was never up for sale.

ESP32-PICO-KIT v4 however has now just launched, and Electrodragon offers it for $10 plus shipping.

Board specifications:

  • SiP – ESP32-PICO-D4 802.11 b/g/n WiFi + Bluetooth LE system-in-package
  • 3D antenna
  • USB – 1x micro USB port for power and programming;  CP2102 USB-TTL Serial Bridge
  • Expansion – 2x 20-pin headers with I/O and power signals. 2x 17-pin male headers soldered
  • Misc – EN and Boot buttons, on board power indicator LED.
  • Power regulator – AMS1117 3.3V regulator
  • Auto reset circuit
  • Dimensions – 51 x 20 mm

This board can be used like any other ESP32 board with ESP32 IDF SDK, Arduino Core, Micropython, and so on, it’s just narrower than most.

Other ESP32-PICO-D4 based boards have been launched such ESP32-PICO motherboard sold for $16 on Tindie, or TTGO T7, recently discovered by Time4EE, that can be purchased for $8.50 plus shipping on Aliexpress. The latter is however quite wider than the official Espressif devkit (estimated dimensions: 50×30 mm), but does provide a battery connector


Standard ESP32 boards can now be purchased for as low as $5, so boards based on the SiP are currently a little bit more expensive, but I’d expect the price difference to come down overtime.

Giveaway Week – ESP32 PICO Kit v3 Boards

November 1st, 2017 240 comments

I don’t have one, but eight boards to give away to four winners (2 each) with Espressif Systems ESP32 PICO Kit v3 board based on ESP32-PICO-D4 SIP, an all-in one package with ESP32, 4MB SPI flash, crystal oscillator, and passive components, which allows for smaller boards.

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The board is very similar to any other ESP32 boards, and software compatible, but it’s just quite thinner, and easier to work with on breadboards. Since I had already played with Arduino Core and Espruino (JavaScript) on other boards, I used one of the 10 boards provided by Espressif to play with Micropyhon on ESP32.

Each winner will get two ESP32 PICO Core board in order to make it worthwhile with regards to shipping costs.

To enter the draw simply leave a comment below. Other rules are as follows:

  • Only one entry per contest. I will filter out entries with the same IP and/or email address.
  • Contests are open for 48 hours starting at 10am (Bangkok time) every day. Comments will be closed after 48 hours.
  • Winners will be selected with, and announced in the comments section of each giveaway.
  • I’ll contact the winners by email, and I’ll expect an answer within 24 hours, or I’ll pick another winner.
  • Shipping
    • $4 for registered airmail small packet for oversea shipping payable via Paypal within 48 hours once the contest (for a given product) is complete.
    • If Paypal is not available in your country, you can still play, and I’ll cover the cost of sending the parcel by Sea and Land (SAL) without registration if you win.
  • I’ll post all 10 prizes at the same time, around the 8th of November
  • I’ll make sure we have 10 different winners, so if you have already won a device during this giveaway week, I’ll draw another person.

Good luck!

The boards above are not for sale yet, but the similar ESP32-PICO motherboard is sold for $16 on Tindie. Alternatively, you could contact Espressif Systems, if you are interested in getting ESP32 PICO Core samples.

Getting Started with MicroPython on ESP32 – Hello World, GPIO, and WiFi

October 16th, 2017 18 comments

I’ve been playing with several ESP32 boards over the months, and tried several firmware images. I started with a tutorial for Arduino Core on ESP32, a few month later I tested ESP32 JavaScript programming with Espruino on ESPino32 board, and recently Espressif Systems sent me ESP32 PICO core development board powered by their ESP32-PICO-D4 SiP, and while I took some pretty photos, I had not used it so far.

So I decided to go with yet another firmware, and this time, I played with MicroPython on ESP32, and will report my experience with basic commands, controlling GPIOs, and WiFi in this getting started post.

Flashing Micropython Firmware to ESP32 Board

Source code is available on Github, as a fork of MicroPython repo as ESP32 support has not been upstreamed yet. We could built the firmware from source, but there’s also a pre-built binary which you can download on MicroPython website.

I’ll be using Ubuntu 16.04 for the instructions, which should be pretty similar for other Linux distributions, especially the ones based on Debian, and if you’re using Windows 10, you should be able to follow the same instructions after installing Windows Subsystem for Linux with Ubuntu on your computer.

Let’s open a terminal, to download the firmware (October 14):

If you have not done so already, install the latest version of esptool:

Now connect the board via a micro USB to USB cable to your computer. The log should like like:

In my case, the device is ttyUSB0, but it may vary depending on the board used. We can now erase the flash, and copy the firmware to the board:

If the last step is successfull,  the output should be similar to the one below:

As a side note, version 2.1 of esptool does not know about ESP32-PICO-D4, but it can still detect an ESP32 device, and the update went through normally.

Hello World Sample / Boot Log with MicroPython

We can test the firmware, by connecting to the board using minicom, screen, putty, or whatever software you feel most comfortable with. I went with minicom, setup a connection to /dev/ttyUSB0 device with 115200 bps baudrate. I immediately tested the print function, and made an hard reset to check out the boot log:

The reset command will first generate some errors message, before rebooting the board:

We can type help function to get some more help:

I also often refered to MicroPython 1.9.2 documentation to write this quick start guide.

LED Blink Sample with MicroPython

The easiest way to test GPIOs is to connect an LED, since the board does not have any user LED, only the power LED. So I connected an LED to pin 21 via a transistor to ensure enough current passes through it.

Controlling the LED in the command line interface is easy. Import the machine library, set the pin to output, and change the pin level as needed:

Success! But what about doing a proper blink sample? MicroPython developers’ official PyBoard would show as a USB mass storage drive in you computer, where can copy Python files like and files, but in the case of ESP32 PICO core, it appears the only option is to use the serial console for programming, as we can’t simply copy files to the board from the host computer.

I  found a solution on Techtutorialsx – which also has plenty of articles about MicroPython on ESP32/ESP8266. We need ampy script that can be install from our Linux terminal:

However, the first time I tried it I got an error:

I installed files module, but the error remained. So instead I installed it for Python 3:

I then created on my computer to blink the LED every 500 ms:

Before uploading the file to the board, you can try to run it as follow:

If you have plenty of errors here, that’s probably because your code is incorrect. Since I’m not very familiar with Python, it happened to me a couple of times, until I got the code right, and the LED was blinking as expected.

Now that we’ve made sure the code works, we can now copy our sample to the board…

… reconnect to the serial console, and verify the file is there:

To run the program type the following:

The LED should blink again. You can interrupt the program with Ctrl+C, and if you want to soft reset the board, press Ctrl+D.

In order to automatically start the blink program at each boot, rename to, delete, and copy instead:

Power cycle the board, and the LED should start blinking almost immediately.

ESP32 WiFi with MicroPython (Station and AP modes)

We’ve got GPIOs working, but one of the most important feature of ESP32 is obvisouly WiFi. I’ll start by configuring the board in station mode. First import the network library, set the board to station mode, and scan access points:

The latter should return a list of access points with ssid, bssid, channel, RSSI, authmode, and hidden status as explained here.

I can then connect the board to one of the access points with:

The log above with IP address should give  a clue, but you can check connection status with the following function:

and use ifconfig to get the IP info:

Switching to AP mode is easy with the three commands below configuring the board with ESP32-PICO-CNX SSID:

At this stage I can see ESP32-PICO-CNX on my phone, but it’s an open connection. We can change that with authmode option that can take 5 values:

  • 0 – open
  • 1 – WEP
  • 2 – WPA-PSK
  • 3 – WPA2-PSK
  • 4 – WPA/WPA2-PSK

I’ll use WPA2-PSK and define the password with the config function.

Working as planned…

ESP32 Web Server with Micropython

Many ESP32 project will require a web interface for monitoring or configuration. Let’s first setup the board as an access point using the command we’ve used above:

Now create file based on Python code found here that’s supposed to return the status of some GPIO pins in an HTML table:

Copy the file to the board:

Start the serial console again, import/run the python sample we’ve copied, and connect to the board (in my case


It works as expected, but we wrote the HTML code inside the Python file, and you need to handle socket programming by yourself. To further simply the task, some MicroPython web servers such as MicroWebSrv, and Picoweb are available.

MicroWebSrv (Not working yet for me)

I tried to install MicroWebSrv first, but never managed to make it work. I still reproduce the step I followed in case somebody finds out what I did wrong. I got the code, and copied files from the Linux terminal:

We can check the files are where they are supposed to be:

Go into the terminal (aka REPL console) to start a basic example, after setting up a connection:

I could connect to the server, but I would always get 404 error.


So instead I switched to picoweb, adapting the instructions here and there. It’s very easy to install.  First make sure you have a working Internet connection in your board (i.e. set station mode), and install the web server with upip:

That’s the output if everything goes according to plans:

Now let’s go back to the host computer to create an html document, for example index.html:

as well as sample file that will request the HTML page from the board, and return it to the client.

You’ll need to change “” by the IP address of your board.

Let’s copy both files to the board…

… go back to the serial console, connect in station mode, and run the sample:

Type or copy/paste the URL in the last line into a web browser, and you should get the output below.

ESP32 Bluetooth with MicroPython

There’s no Bluetooth support in the official MicroPython documentation, because it’s work in progress, and for the most adventurous MrSulry released an alpha version  a few days ago. The Bluetooth API is also in flux, but the basic code to enable Bluetooth should look like:

I’ll update that section once Bluetooth makes it to the stable release, and/or when I’m sure the API is frozen.

Other ESP32 (Micro)Python Resources

I’ve just covered a few things that can be done with MicroPyhon on ESP32, and beside the official documentation, you can also check the various MicroPython ESP32 tutoral on techtutorialsx blog. Loboris also made another MicroPython ESP32 firmware that supports pSRAM as MicroPython may use a lot of RAM. If you’re interested in Python for ESP32, but Zerynth is another option for Python on ESP32 that works with an IDE/GUI available for Windows, Linux and MAC OS X. [Update: Yet other options are Pumbaa a port of MicroPython running on top of Simba, and Pycom version of MicroPython]

A First Look at ESP32 PICO Core Development Board Powered by ESP32-PICO-D4 SiP

August 30th, 2017 13 comments

Last week, I wrote about ESP32-PICO-D4 system-in-package (SiP) that contains ESP32 WiSoC, 4MP SPI flash, a crystal oscilloscator and some passive components in a single 7×7 mm package in order to allow smaller designs based on ESP32. The company noticed the post, and asked me whether I’d be interested in receiving “some development boards based on ESP32 PICO”, an offer hard to refuse :), and within a couple of days I received the package below.

So I  ended up with 10 identical development kits, the company probably thought it was no worth paying for DHL to only send one or two development boards… The boards may also be part of some contests… We’ll see 😉

So let’s take two, and have a closer look at “ESP32_PICO_Core_Board_V3″… It comes with two rows of 20 pins with access to all I/Os, and features three main chips: ESP32-PICO-D4 SiP, AMS1117 voltage regulator, and Silabs CP2102 USB to UART controller for programming and debugging.

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There’s also an antenna, a EN and BOOT buttons, and a micro USB port. The board measures 52x20mm. On actual product, the USB bridge part would be there, so you could have something around half size or even much smaller…

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… something like the ESP32-PICO-D4 module below whose picture I found on the web.

ESP32-PICO-D4 features are basically the same of ESP32 ones, just more compact, so how does ESP32 PICO Core board compares to other breadboard friendly board based on ESP32? To find out, I compare it to ESP32-T board with ESP32-Bit module, and ESPino32 board with ESP-WROOM-32 module, which I plan to review/play with in about 2 weeks.

ESPino32 vs ESP32 Pico Core vs ESP32-T – Click to Enlarge

ESP32 Pico Core is clearly smaller. Compared to ESP32-T it’s about the same length, but much thinner, and include 2 extra pins, while in terms on functionality it’s more comparable to ESPino32 both with 40-pins, two button, and micro USB port, but the size difference is even greater.

ESP32 Pico Core on Breadboard – Click to Enlarge

If you wonder, the board is breadboard compatible, and since it’s thinner leave two rows of pins free on each side, compared to just one for most boards.

The boards are not for sale right now, and there’s no info on their website about them. You’ll however find some more details in ESP32-PICO-D4 datasheet.

ESP32-PICO-D4 System-in-Package Combines ESP32, 4MB SPI Flash, a Crystal Oscillator, and Passive Components

August 22nd, 2017 2 comments

Espressif Systems has revealed another ESP32 variant, but this time it’s not an SoC, but a 7x7mm system-in-package (SIP) that comes ESP32 dual core processor, a 4MB  SPI flash, a crystal oscillator and various passive components, so that you don’t need to include those in your design, and create an ultra-compact PCB for wearables and other space-constrained applications.

ESP32-PICO-D4 Internal Schematics – Click to Enlarge

ESP32-PICO-D4 SiP specifications:

  • SoC – ESP32 with two Tensilica LX6 cores, 448 KB ROM, 520 KB SRAM (inc. 8KB RTC memory), 1kbit eFuse
  • On-module Flash – 4MB SPI flash
  • Connectivity
    • WiFi – 802.11 b/g/n/e/i (802.11n up to 150 Mbps)
    • Bluetooth – Bluetooth V4.2 BR/EDR and BLE specification; ; class-1, class-2 and class-3 transmitter; Audio: CVSD and SBC
  • SIP Interfaces
    • SD card, UART, SPI, SDIO, LED PWM, Motor PWM, I2S, I2C, IR
    • GPIO, capacitive touch sensor, ADC, DAC, LNA pre-amplifier
  • Sensors –  On-chip Hall sensor & temperature sensor
  • Clock – On-module 40 MHz crystal
  • Power supply – 2.3 ~ 3.6V
  • Operating current – Average: 80 mA
  • Temperature range –  -40°C ~ 85°C
  • Package dimensions –  7.0±0.1 mm x 7.0±0.1 mm x 0.94±0.1 mm

I understand ESP32 supports up to 16MB flash, so future ESP32-PICO-D16 SIP might be possible too. The second schematics in the datasheet shows what a basic board with ESP32-PICO SIP looks like.

ESP32-PICO-D4 Module Peripheral Schematics – Click to Enlarge

The company explains the SiP is particularly suited for any space-limited or battery-operated applications, such as wearable electronics, medical equipment, sensors and other IoT products. Beside the datasheet, there’s currently very little information about ESP32-PICO-D4 on the web, so we’ll have to wait to see what comes out of it.

[Update: Photo of module with ESP32-PICO-D4


Via ESP32net Tweet