I present the new module MOD-20.Z Xmega eXploreGO of Modułowo, with the microcontroller ATXmega128A4U and MP3 decoder VS1003B. The module has an DataFlash memory and a microSD card connector. You can connect a Bluetooth module and a radio module nRF24L01. The module can be programmed via USB or programmed/debugged using the connector PDI, derived on the edge of the platform. All signals from the microcontroller are routed to external connectors. Signals connected to VS1003B and DataFlash have SMD jumper and they can be disconnected at any time, in the case of using signals for other purposes. On the edge of the plate also put a small switch ON / OFF for USB power.
The module has two configuration jumpers for selecting the power supply from the USB connector or the VIN. Xmega eXplore GO has a connector’s compatible with the Arduino platform, enabling connection of Arduino shield’s. Microcontrollers ATXmega tolerate voltage +3.3 V, each signal has a built-in resistor with a value of 3.6 kR, allowing you to connect systems +5 V. In some cases they can interfere, so most of the resistors has a SMD jumper on the opposite side. The module is available in two basic versions: with the block VS1003B (MP3 version) and without. A cheaper version will allow the use of the module as a development platform for microcontroller ATXmega128A4U. Below is a picture showing the contents of Xmega eXploreGO.
more info here: XMEGA EXPLOREGO ENG
Xmega eXploreGO – a new module with ATXMEGA mcu and mp3 support - [Link]
James Wood designed a simple circuit that is able to indicate when the battery of a system is low and needs replacement. He writes:
The Design Idea in Figure 1 indicates a low-battery condition in an audio test instrument that is powered by four AA cells. As the instrument was otherwise an all-discrete design, this same approach seemed more in keeping with the spirit of the project than the use of a single-sourced integrated circuit.
A garden-variety red LED serves as both the indicator and the voltage reference. A small current through R5 forward biases the LED, but its glow at this low value is barely visible, even in a dark room.
Simple circuit indicates a low battery - [Link]
Industry’s Widest Range Current-Sense Amplifier Measures 10mA to 10A without Increasing Measurement Errors
The MAX44284 is a high-side, current-sense amplifier that operates with a 1.7V to 5.5V single supply and is optimized for very low power operation with only 21µA of quiescent current.
The MAX44284 offers precision accuracy specifications of 2µV VOS and gain error of 0.05% (max). The device features an input common-mode voltage range from -0.1V to +36V. This current-sense amplifier has a voltage output and is offered in four different gain versions.
MAX44284 – 36V, Input Common-Mode, High-Precision, Low-Power Current-Sense Amplifier - [Link]
Bajdi did some tests for switch mode voltage regulators:
There are different types of DC-DC regulators. The most common are linear and switch mode regulators. Everyone that has tinkered with electronics has probably used a 78xx series linear regulator. They are easy to use since they don’t need any special components. With most linear regulators you just put a capacitor on the input and one on the output and they will work.
Testing switch mode voltage regulators - [Link]
The LT6015 is a single Over-the-Top operational amplifier with outstanding precision over a 0V to 76V input common-mode voltage range. It incorporates multiple built in fault tolerant features, resulting in no-compromise performance over wide operating supply and temperature ranges. Over-the-Top inputs provide true operation well beyond the V rail. The LT6015 functions normally with its inputs up to 76V above V-, independent of whether V+ is 3V or 50V. Input offset voltage is 80μV max, input bias current is 5nA and low frequency noise is 0.5μVP-P, making the LT6015 suitable for a wide range of precision industrial, automotive and instrumentation applications. Fault protection modes guard against negative transients, reverse battery and other conditions. The LT6015 is available in a 5-lead SOT-23 package and is fully specified over -40°C to 85°C, -40°C to 125°C, and -55°C to 150°C temperature ranges.
LT6015 – 3.2MHz, 0.8V/μs Low Power, Over-The-Top Precision Op Amps - [Link]
By Ashok Bindra:
The use of low-dropout regulators, popularly known as LDOs, is common in many applications today because they provide a simple and inexpensive way to regulate an output voltage that is stepped-down from a higher input voltage. In addition, linear LDO voltage regulators contribute very-low noise as compared to switching regulators.
Nonetheless, to keep system power consumption low, such regulators must also feature ultra-low quiescent current (IQ) while providing excellent dynamic performance to ensure a stable, noise-free voltage rail, suitable for driving IC loads such as microprocessors, FPGAs, and other devices on the system board.
Selecting the Right Ultra-Low Quiescent-Current LDO Regulator - [Link]
UC20 module already provides besides a high speed UMTS/HSPA+ data transfer even the reception of data from GPS/ Glonass satellites.
When company Quectel launched on the market the UC20 3G module a few months ago, they also announced a forthcoming enhancement of functionality for reception of GPS/Glonass. We can unveil with pleasure, that reception of GPS/ Glonass signal via the UC20 module is already a reality and so this module has become one of the most versatile communication modules on the market. Combination of GSM/GPS/Glonass enables for example to design a device for monitoring of position of vehicles, goods, etc, by means of a single module.
At the same time, we also incorporated into our standard stock offer a miniPCIe version – UC20-E-MINIPCIE, increasing flexibility of usage of the module. All further information can be found in our recent article: Quectel 3G modules of UC20 series will ensure a fast transmission even on 900 MHz.
Quectel UC20 integrates GSM and GPS into a single module - [Link]
Dave reviews the Canadian Advance Devices Smart Tweezers LCD meter. What will he find? Does it cut the mustard?
Bonus LCR meter tutorial at the end.
EEVblog #81 – Smart Tweezers LCR Meter Review And Teardown - [Link]
Diyouware build a low-cost PCB printer for photoresist using a blue ray module. The UV laser scan the PCB surface and sensitize the UV resistive dry film.
About a year ago my brother and I engaged on a quixotic project to build from scratch a low-cost PCB printer for photoresist.
Finally we did it using a Blue Ray optical pickup (PHR-803T) and his UV laser/electronics to sensitize Dry-film.
The optical pickup is used through his own connector without any modification. We deduced the pinout using reverse engineering and designed a driver for an Arduino UNO to control it. Basically, we can adjust the laser power, turn the laser on/off, move the focus lens servo and read the photodiode array signal.
The control of the pickup allowed us implementing a laser auto-focus algorithm based on the astigmatic method. Is the same method use it to focus the laser beam on the Blue Ray disc.
The mechanics is an X/Y Cartesian table which moves the pickup with two Nema 16 stepper motors and T2.5 timing-belts. Most of the printer framework has been printed with a 3D Reprap printer, so itʼs replicable.
We also developed the Arduino UNO firmware, based on 3D printer firmware Marlin, and the server side software which send the HPGL commands to the printer. Eagle Cadsoft complete the “tool-chain”. It supports HPGL in his CAM processor, so is easy to design the circuit with Eagle, generate the HPGL file and send it to the printer.
DiyouPCB is a prototype and it’s still not perfect: we have some resonance and vibration issues that affect the quality of printing, but it’s a first step to have an alternative method to indirect methods as the famous toner transfer.
DiyouPCB is a PCB printer which uses a Blue Ray™ pickup - [Link]