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27 Feb 2015


Project has been designed to record & playback multi voice massages using Winbond’s ISD1740 IC. Messages are stored in flash memories made in unique Multilevel Storage Technology (MLS). Circuit provides high quality audio recording and simple operations. Circuit operates in dual mode standalone or micro-controller SPI mode. Onboard tactile switches for standalone mode and 10 (2×5) pin box header connector for SPI mode. 26 to 80 Seconds voice massage recording capacity.


– Supply 2.4 to 5 VDC (5 VDC @ 100 mA)
– 26 to 80 Seconds selectable voice recording capacity
– Selectable sampling rates 11.5 KHz, 7.8 KHz, 6.4 KHz, 5.3 KHz, 4.5 KHz
– Directly drive 8 Ohms speaker or typical buzzer
– Analog audio out to driver external audio amplifier
– Digital volume control via onboard tactile switch
– Dual mode operation stand alone or micro-controller
– SPI Interface (4 wire serial interface)
– 10 (2×5) Pin box header for SPI interface
– Full control on memory and analog path configuration audio input, output and mix in SPI mode
– Automatic power-down after each operations cycle (standalone mode)
– Onboard tactile switch for Record, Play, Erase, FWD, Volume control, Reset and Feed-Through
– Onboard power indication, record play indication
– Voice message fed in via microphone or analog signal in
– ISD1740 provides a PWM class D speaker driver and speaker output simultaneously –
– 100 Years message retention
– 100,000 Record cycles
– Four mounting holes of 3.2 mm each
– PCB dimensions 80 mm x 76 mm

20 to 80 Seconds Voice Record Playback with SPI control - [Link]

21 Feb 2015


by elektor.com:

A recent press release by Linear Technology announced the introduction of the LTC2373-18 low noise, high speed, 8-channel, 18-bit, 1 Msps, successive approximation register (SAR) ADC. The device is capable of operating from a single 5V supply and features a highly configurable, low crosstalk 8-channel input multiplexer, supporting fully differential, pseudo-differential unipolar and pseudo-differential bipolar analog input ranges. The LTC2373-18 achieves ±2.75LSB maximum integral nonlinearity for all input ranges with no missing codes at 18-bits and a typical SNR of 100dB for fully differential inputs and 95dB with pseudo-differential inputs.

The temperature-compensated onboard 2.048 V reference has a maximum drift of 20 ppm/°C and a singleshot capable reference buffer. For control the LTC2373-18 has a high speed SPI-compatible serial interface that supports 1.8 V, 2.5 V, 3.3 V and 5 V logic through which a sequencer with a depth of 16 may be programmed. An internal oscillator sets the conversion time, easing external timing considerations. The LTC2373-18 dissipates 40mW and automatically naps between conversions to reduce power consumption. This power saving feature is scaled in accordance with the sampling rate. A sleep mode is also provided which reduces power consumption to 300 μW during inactive periods.

Highly Configurable 8-Channel ADC - [Link]

6 Feb 2015


by Pieter @ piconomic.co.za:

If you can beg, steal or borrow an Atmel ISP programmer, then you can use the Arduino environment to develop on the Atmel AVR Atmega328P Scorpion Board. An Arduino on Scorpion Board guide, Optiboot bootloader and example sketches have been added.

If you own an Arduino Uno board, you can now try out the Piconomic FW Library risk free without abandoning the creature comforts of the Arduino environment. You can use the existing Optiboot bootloader to upload code. I have added a getting started guide for the Arduino Uno. There are examples, including a CLI (Command Line Interpreter) Application that creates a “Linux Shell”-like environment running on the Arduino Uno so that you can experiment with GPIO, ADC, I2C and SPI using only Terminal software (for example Tera Term)… it is really cool!

Piconomic FW Library 0.4.2 released - [Link]

4 Feb 2015


Teensy-LC (Low Cost) is a powerful 32 bit microcontroller board, with a rich set of hardware peripherals, at a very affordable price!

Teensy-LC delivers an impressive collection of capabilities to make modern electronic projects simpler. It features an ARM Cortex-M0+ processor at 48 MHz, 62K Flash, 8K RAM, 12 bit analog input & output, hardware Serial, SPI & I2C, USB, and a total of 27 I/O pins. See the technical specifications and pinouts below for details.

Teensy-LC maintains the same form-factor as Teensy 3.1, with most pins offering similar peripheral features.

Teensy LC – Coming March 2015 - [Link]

23 Jan 2015



This minimalistic board is packed with features and comes with an extensive ecosystem of documentation and firmware.

For the student (we are never too old) that wants to fast track his career as a professional firmware developer there is:

  • a detailed getting started guide
  • an Atmel AVR quick start guide, with tutorials and examples
  • Recommend best practices

For the developer that wants to improve his game there is:

  • A header to quickly connect different kinds of peripherals (GPIO, A/D, UART, SPI & I2C). Notice that each interface has it’s own +3V3 and GND pins to make wiring easier and also improves EMC.
  • A full-featured CLI application to experiment with the connected device and verify that it works, before committing to a single line of C code.
  • A firmware framework that lays the foundation so that you can quickly develop a new application.
  • A Temp&Pressure Logger and Analog voltage Logger application that demonstrates how you can quickly develop your own custom logging application using the onboard AT45D DataFlash.

Atmel ATmega328P Scorpion Board - [Link]

31 Dec 2014


by blog.vinu.co.in:

While trying to open a chinese camera pen, unfortunately the PCB inside it got damaged. Few of the PCB traces got cut and it became useless. After few days, I removed an 8 pin IC with SO8 package from the PCB. I was curious to know what it is, so I googled the part number 25FW406A but I couldn’t find any exact match. I found some part number similar to that and I concluded that it is an SPI flash. Later I got a datasheet from ‘ON semiconductor’ for a similar part -LE25U40CMD which is a 4M-bit SPI flash memory. I soldered the IC on a common board, powered it with 3.3v and interfaced it to a TI stellaris launchpad via SPI port. According to the datasheet the SPI port need to be initialized in mode 0 or 3. I tried few commands listed in the datasheet and got proper response from the chip, the CHIP ID doesn’t matches but that is expected because it is not the same part. I wrote functions for erasing, reading and writing the flash memory and tested it successfully using the launchpad.

Happy Christmas and Happy New Year wishes from Attiny13 - [Link]

9 Dec 2014


Serial camera module that captures time-lapse and stop-motion videos plus images to uSD card. Use with any micro like mbed and Arduino.

ALCAM allows any embedded system with a serial interface (UART, SPI or I2C) to capture JPG/BMP images and also to record them right onto an SD card. Also, ALCAM gives you the ability to create time-lapse and stop-motion AVI videos and save them directly to the SD card. All done through a set of simple and well documented serial commands. ALCAM can also capture images and videos though a special pin, without the need to send any commands.

ALCAM-OEM – Serial camera module - [Link]

25 Nov 2014


Most Arduino SPI tutorials show this simple but poor SPI bus design. In this article a new approach is discussed.

Better SPI Bus Design in 3 Steps - [Link]

24 Nov 2014


An app note from Atmel, digital sound recorder with AVR and DataFlash (PDF!):

This application note describes how to record, store and play back sound using any AVR microcontroller with A/D converter, the AT45DB161B DataFlash memory and a few extra components.
This application note shows in detail the usage of the A/D Converter for sound recording, the Serial Peripheral Interface – SPI – for accessing the external DataFlash memory and the Pulse Width Modulation – PWM – for playback. Typical applications that would require one or more of these blocks are temperature loggers, telephone answering machines, or digital voice recorders.


Digital sound recorder with AVR and DataFlash - [Link]

24 Nov 2014


by marc2203 @ importhack.wordpress.com:

I’m not going to explain in detail what is ESP8266 because if you have found this post I’m sure you already know it. But just in case, it is an awesome cheap board (less than 4$) with built-in wifi communication (802.11 b/g/n), and SPI, UART. You can also use its processor to run your code.

How to use ESP8266 ESP-01 as a SENSOR web client - [Link]





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