ESP8266-based Clock Synchronized With Network Time Service

Thanks to Internet, the problem of time shifting in embedded and connected devices was solved using time synchronization over Internet.

National Institute of Standards and Technology provides a service called Network Time Service (NTS) over the Internet. The project of ESP8266-based clock, published on embedded-lab, is going to demonstrate how to make a benefit from NTS to accomplish time synchronization over the Internet.

This clock retrieves time information from NTS and display it on a 4-digit seven segment LED display, and the connection to NIST time server through your local WiFi network will be by using ESP-01 WiFi module.


The 4-digit seven segment LED display breakout includes MAX7219 IC which is a seven segment driver. Three GPIO pins from ESP8266 module are used, where MAX7219 needs one for serial input,one for clock line and one to drive LOAD pin of MAX7219.



The firmware was developed using Arduino core for ESP8266. The firmware queries the time from NTS with 2-minutes interval that because NIST does not allow queries to any of their servers more frequently than once every 4 seconds, according to the blog post. During the 2-minutes, time display is kept running locally using the delay() routine.

To see the full instructions and to download the code you can visit the embedded-lab blog.


AriCalculator – A homemade handheld calculator


The AriCalculator is a DIY calculator or a general purpose handheld device.

It is battery powered and runs on a NXP S12G240 microcontroller (16-bit, 240k flash, 11k RAM). The device has 38 input keys and a 128×64 pixel LCD display with a backlight option. Three interfaces connect the calculator to the outside world:

  • A BDM debug interface, giving direct access to the microcontrollers on-chip memories and debug features.
  • A USB port, offering a FTDI virtual com port (VCP). This port is under software control and intended to serve as a programming interface.
  • A general purpose SPI port, intended for hardware extensions.

AriCalculator – A homemade handheld calculator – [Link]

Sunburn Monitor – A UV monitor

Sunburn Monitor is a UV monitor with sound-based indication. It calculates the max sun exposure before sunburn based on your skin type.

The project was published over by [Quarterturn].


It’s based around SI1132 light sensor from Silicon Labs. SI1132 is a UV index and ambient light sensor with I2C interface and it’s available in 10-lead 2×2 mm QFN package. Sunburn Monitor uses ATMEGA168 MCU where the firmware was developed using Arduino environment.

The design has a protection transistor Q1 (DMP2035U-7) in the input, we covered in a past blog how to protect you circuit from reverse voltage, and Q2 is used to enable/disable the supply voltage of the sensor.

Sunburn Monitor powered by a 3v CR2032 battery with power management relies primarily on either deep sleep via hardware interrupt or watchdog timer interrupt for sleep-wake-sleep monitoring cycles, according to [Quarterturn].



The source code and the design files, using Eagle CAD, (SCH & BRD) can be found here.
[Project page over]

The First Release of ESP-WROOM-32 Module Datasheet

It has been a while from the announcement of the new SoC ESP32 from Espressif.
Recently, Espressif released the ESP-WROOM-32 module which is based on ESP32 SoC, the big brother of the well know ESP8266 WiFi module.
ESP32 is a 2.4 GHz Wi-Fi and Bluetooth combo chip with dual CPU cores and a very rich set of peripherals, ranging from capacitive touch sensors, Hall sensors, low noise sense amplifiers, SD card interface, Ethernet, high speed SDIO/SPI, UART, I2S and I2C.

The datasheet of ESP-WROOM-32 module contains pin definitions, functional description, electrical characteristics and a schematic.

ESP-WROOM-32 Specifications
ESP-WROOM-32 Specifications

ESP32 contains two low-power Xtensa ® 32-bit LX6 microprocessors with 448 KBytes ROM and 520 KBytes on-chip SRAM for data and instruction and supports 4 x 16 MBytes of external QSPI flash and SRAM.
It has various power modes. A 160 ~ 260 mA  power consumption for Wi-Fi Tx packet @ 13 dBm ~ 21 dBm.

Power Consumption by Power Modes
Power Consumption by Power Modes
ESP-WROOM-32 Schematic
ESP-WROOM-32 Schematic

“New SDK features, tutorials and example applications will be released over the next few months.” according to the datasheet.


[datasheet link]
Via: Time4EE

Charge-pump topology doubles voltage


has designed a circuit that is able to double the input voltage and breaks DC path.

I once needed a voltage doubler circuit with no DC leakage path between input and output, and ended up devising this unusual 556- (dual 555 timer) based circuit with a “floating” voltage output.

Charge-pump topology doubles voltage – [Link]

Micro-displacement sensor resolves 10 microns

An optical micro-displacement sensor from Omron Electronic Components Europe is capable of resolving 10 microns – one tenth the diameter of a human hair or the thickness of a coat of paint. by Graham Prophet @

The high resolution of the Z4D sensor suits it for paper thickness and multi-feed detection office equipment and ATMs, as well as travel detection in industrial automation systems, consumer electronics and other applications.

The Z4D-C01 locates target objects optically without the need for contact. Location is determined and movement detected by changes in the location of light reflected from the object.

iPhone Battery Charger / Tester

iphone-charger_v2-2_4 has designed an iphone battery charger /tester.

I have seen technicians often replace batteries when they may not necessarily need to be or ignore the fact that they could be the cause of the issue at hand. To remedy this I designed a basic iPhone battery charging breakout board system. The system can charge a battery, has the option for expansion to support newer/other batteries and breaks out the battery status pins which can be read from a microcontroller or some other means. It consists of 6 battery connector boards (iPhone 4, 4S, 5, 5S/C, 6, 6+) and a main charging board.

iPhone Battery Charger / Tester – [Link]

Moto Mods Development Kit – Make Your Own Extension for Moto Z Phone

Moto Z Droid and Moto Z Force Droid are the new phones from Motorola. They run Android 6.0 on a Qualcomm Snapdragon 820 SoC with a lot of other features.
Motorola brought modularity to Moto Z using the hackable “Moto Mods” backplate expansion system. Motorola’s Moto Mods attach to the back of the phone with strong magnets and are hot swappable (plug and play).

According to the ANANDTech review, “Attaching a Moto Mod produces a small vibration and audible alert confirming that it has been automatically recognized. For any Mods with internal batteries, there’s a notification that pops up showing the charge level, which also appears in the battery section within the settings app and in the notification shade. There’s a dedicated “Moto Mods” page also in settings for updating the Mod’s firmware, managing its settings, and reading its instructions.“.

Images courtesy of anandtech
Images courtesy of anandtech


Motorola wants makers to have the ability to develop their own Moto Mods, so they collaborated with Element14, the well known distributor of technology products and solutions for electronic system design, to offer a Moto Mods Development Kit for building custom Moto Mods.

Images courtesy of
Images courtesy of

According to Element14, Moto Mods Development Kit consists of the reference Moto Mod, a perforated board for you to solder your own components to,  or HAT adapter board enables you to attach a wide variety of Raspberry Pi HATs to your Moto Mods™ Development Kit and an example cover.

HAT adapter board
HAT adapter board
From top to bottom: example cover, a perforated Board and reference Moto Mod, Images courtesy of
From top to bottom: example cover, a perforated Board and reference Moto Mod, Images courtesy of

The reference Moto Mod is the core component to interface with Moto Z, processing resources, GPIO and standard peripheral interfaces, power and charging control.

The reference Moto Mod ,Images courtesy of
The reference Moto Mod ,Images courtesy of

Motorola has created several personality cards that can be inserted into the reference Moto Mod through the 80-pin connector. Each of these personality cards is a full example with open-sourced Moto Mod firmware and an Android application.

Each personality card has a documentation page in the developer site of Moto Mod to reach all the resources needed from schematic to source code.

hw-b2b-diagram-1Moto Mod Ref

The Reference Mod Mod includes:

  • Mechanical and Electrical Interface to enable connection with Moto Z.
  • Moto Mod Microprocessor (MuC) with 96k ROM powered by a Cortex-M4 based STML476.
  • Moto High Speed Bridge.
  • 80 pin connector exposing all developer interfaces.

To develop the Moto Mod-aware applications, you can use the SDK, included in the Moto Mods development toolkit, with the requisite APIs for developing.


More technical information on Moto Mods and the MDK may be found at:

About the  availability, Element14 said “Global availability for these products is due to follow in autumn 2016″.
Via: hackerboards

ESPTool – A WiFi Security Tool

Daniel Grießhaber over created a project called ESPTool. It is a tool to test WiFi networks security and to demonstrate how easy it is to crack a WiFi password or jam a WiFi network. Daniel designed ESPTool for education and self-test purpose.


The Device has SSD1306 based OLED display, microSD card socket, 3 general purpose buttons, ESP8266-12E module, TPS63031 Buck-/Boost converter with an input range from 1.8V – 5.5V, MCP73831 Single-Cell LiPo Charger Chip and CP2012 USB to UART converter chip.


The firmware of ESPTool has the following layers of attacks, according to Daniel’s documentation:

  • Layer 1:

Since the ESPs Radio is not really configurable, it is not possible to create a WiFi Jammer that works by emitting broadband noise or any other Layer 1 attacks.

  • Layer 2:
    • Deauthentification attack
    • Collecting authentication frames and save the keys to SD card for later decryption (using a wordlist on a computer, the ESP neither has enough memory nor enough processing power to crack them on the system)
    • arp spoofing and session hijacking when connected (needs investigation)
    • evil twin hotspot
  • Layer 3 (after connecting to an AP):
    • Host discovery (IP Scanner)
    • Ping flooding (ICMP Pings)
  • Layer 4 (after connecting to an AP):
    • Port Scan on Host



The source code and the design files, using Eagle CAD, (SCH & BRD) can be found here.

[Project page over]

SMDGuide – A gift for all electronic enthusiasts


Alberto @ has published the first pages of a series of SMD components guides. Total guide will consist of 20 pages.

The definitive guide to SMD components!
Cheat Sheets, Package Types, Conversions, Size Codes and more…

SMDGuide – A gift for all electronic enthusiasts – [Link]