Electro Labs has posted a detailed tutorial on why and how to use bypass capacitors:
You may have heard about the phenomenon of bypassing in circuits, however, we may not have sufficient knowledge of how to apply this technique in real circuits. In this tutorial, we will discuss about the bypass capacitors, why we need to use and how to use these capacitors in circuits.
Via Hacked Gadgets.
Xykon writes:
I haven’t used my PSoC board in a while so I checked what’s new and found a new ready to use waveform generator component that makes use of the built-in 8bit dac. I went straight ahead to check it out…
Beside the standard sine/square/triangle/sawtooth forms you can either draw your own pattern directly in the tool or load one from a file. About 5 seconds later you have your configured waveform on the analog port. You can even pre-define two different forms and switch between them through a digital input or in software. Click here to go to the component website where you can also download the complete datasheet for all the possible options. This is supported on all PSoC3/4/5/5LP chips so it’ll even work with the Dangerous Prototypes EzPSoC3 board , the PSoC5LP based freeSoC boards and the PSoC4 pioneer kit which won element14 product of the year.
Via the forum.
Andrew Rohne blogged about his free Bus Pirate v3.8 PCB build. The Bus Pirate is an open source hacker multi-tool that talks to electronic stuff.
If you build a free PCB we’ll send you another one! Blog about it, post a picture on Flicker, whatever – we’ll send you a coupon code for the free PCB drawer.
Get your own handy Bus Pirate for $30, including world-wide shipping. Also available from our friendly distributors.
jry shared his simple DIY JBC soldering station in the project log forum:
Current status: transformer inside old PSU housing as temporary solution. I don’t want to mess with mains on my desk. For now battery powered (3.2V LiFePO4) logic part. Opamp, Atmega328p, three buttons, LCD (waiting for b&w OLED instead of this one for better contrast and faster refresh rate).
Via the forum.
Destate9 writes:
So I’ve been trying to make a constant current H-bridge circuit for a project, and I’m running into trouble with PWM. Right now, all I have connected to the Output compare pin of my PIC32MX microcontroller is a 330uF capacitor (Max ESR of 1.4 ohms according to datasheet). I assumed a 50% duty cycle (at VCC = 3.3V) would yield 1.65V, but that is not the case. As you can see in my attached picture, the output voltage (y-axis) vs Duty Cycle (divide the x-axis by 65535) looks a little more like a CDF. I know there must be a way to calculate this function based on the capacitor charging and discharging, but I’ve been scratching my head for a while, and was wondering if anyone else has derived this function.
Via the forum.
herpderp writes:
Just few words for those who are interested by the new PIC32MZ (200MHz, 2MB flash, 512KB RAM) and the LCC solution (Low Cost Controllerless): a FEA from Microchip provided me a development board based on this new microcontroller. After some adaptations, software of the smart TFT module partially works on this board (by partially, I mean that some devices such as the SD card are not yet handled). After some optimizations, 2D primitives became so fast that it is now possible to make 2D games with a correct frame rate (about 60 – 70 fps for a 460×240 resolution @ 16bpp, with double buffering). The 2MB flash also allows storing large 16bpp graphics, even without compression.
Via the forum.
Check out the video after the break.
Continue reading “PIC32MZ / MEB2 (LCC solution, custom software)”
Steven Casagrande posted an update on his open source hardware GPIB USB adapter:
After many days, I just finished off firmware version 5 for my adapter. This is probably my biggest update yet. A lot of people asked for compatibility with the Prologix commands so that’s what I focused on. Here is an overview of the new firmware:
- Nearly all Prologix command set support. The adapter should now work with some pre-existing software tools and examples on the internet that were originally intended. Some will require a few changes for baud rate and flow control settings
- Improved termination character handling
- SRQ support (but no parallel polling, only serial)
- Improved stability
- Device mode (first version so there may be fixes in the future)
- Most settings can be stored in EEPROM
- Basic FIFO buffer for data sent from the PC
Via the forum.
Ricros posted his free NXP ARM Cortex M0/M3 LQFP-48 Breakout board PCB build:
A long time ago I’ve received a NXP ARM Cortex M0/M3 breakout board free pcb and I got a Open Bench Logic Sniffer out of a swag bag, I only had time to solder the free pcb last week.
The MCU is a LPC1313, the cheapest cortex m3 that I could find that would be pin compatible with the footprint on the PCB and I’ve programmed the blink example from lpcXpresso on it with flash magic and a FTDI breakout board.The Open Bench Logic Sniffer wasn’t working when I received it, there was short between two tracks, it was already been cut but it wasn’t enough, there was still a little bit of copper connecting the two tracks, after a few passes with a sharp knife and reflashing everything it was working.
Thanks Ian and Dangerous Prototypes
Via the forum.
If you build a free PCB we’ll send you another one! Blog about it, post a picture on Flicker, whatever – we’ll send you a coupon code for the free PCB drawer.
A great app note from STMicroelectronics on Solar lighting application.
The solar-LED streetlight controller described in this application note is designed to achieve an 85 W solar energy battery charger and a 25 W LED lamp driver. During the daytime the controller preserves the electricity energy gathered by the solar module (PV module), then stores it in the battery. In the evening the controller uses the battery energy to power the LED streetlight. When the battery runs out of power after several rainy days, the controller enables the external offline power supply (not included in this system) instead of the battery to power the LED streetlight until the system battery is fully charged again.
We go through a lot of prototype PCBs, and end up with lots of extras that we’ll never use. Every Sunday we give away a few PCBs from one of our past or future projects, or a related prototype. Our PCBs are made through Seeed Studio’s Fusion board service. This week two random commenters will get a coupon code for the free PCB drawer tomorrow morning. Pick your own PCB. You get unlimited free PCBs now – finish one and we’ll send you another! Don’t forget there’s free PCBs three times every week:
Get yourself familiar on STM32Fxxx Timer peripherals with this app note from STMicroelectronics
This document:
• presents an overview of the timer peripherals in the STM32F0, STM32F1, STM32F2,
STM32F4 and STM32L1 microcontroller series, STM32F30xC/Bx, STM32F358xC,
STM32F37x microcontrollers lines.
• describes the various modes and specific features of the timers, such as clock sources,
• explains how to use the available modes and features,
• explains how to compute the time base in each configuration,
• describes the timer synchronization sequences and the advanced features for motor
control applications, in addition tothe general-purpose timer modes.
Here’s an application note from Microchip: Debugging stand-alone real-time clock/calendar-based applications (PDF!)
An increasing number of applications require Real-Time
Clock/Calendar (RTCC) devices.
Microchip’s RTCC’s (I2C™ and SPI) are feature-rich
devices that incorporate EEPROM, Time/Date
registers, Time-Stamp registers, alarm modules,
SRAM, a watchdog timer, and event detect modules,
making them useful in many timekeeping applications.This application note describes how to debug an application using Microchip’s MCP794XX and MCP795XX RTCC devices.
An application note from Maxim: Direct-sampling DACs in theory and application
High-speed digital-to-analog converters (DACs) with high resolution in the 12- to 14-bit range enable new types of transmitter designs that employ a direct modulation scheme. In such designs, the modulated transmission signal is generated directly on the base frequency. This application note explains how direct-sampling RF DACs enable new communications systems like high-speed cable infrastructure applications.
A similar version of this article appeared in German in the July 2012 issue of Elektronik Informationen magazine.
Claudio Giuliani has designed an RTL-SDR based wide spectrum analyzer.
The code is available on AlterVista. Software prerequisites are a Linux box (no Windows/OSX version) with Gnuradio and rtl_sdr utilities installed. The spectrum analyzer program is a frontend GUI of rtl_power for spectrum visualization and control and is coded in Basic for Gambas (a sort of VisualBasic for Linux.)
Via RTL-SDR.com.
Boris Landoni from Open Electronics writes:
With this short guide we release today, we will explain you how to use your Arduino Yun to do something that was never accomplished before with a board of such family.
We’ll face a real embedded project, with its set of sensors and management and control applications. Thanks to our experiment shield (more info), you’ll manage the sensors via a web browser, having no need of writing a software.
Marios Andreopoulos writes:
A few days ago I wrote a blog post about Arduino and EMI. By using fast PWM and a plain breadboard wire, I was able to detect electromagnetic interference using a usb TV tuner, with its antenna near my circuit. Not only that, but by manipulating duty cycle to create a primitive form of amplitude modulation, I was able to transfer through EMI a very simple audible signal (few notes of one of the most famous riffs) in many frequencies and up to 1.76GHz
Via the contact form.
Check out the video after the break.
Continue reading “Fast PWM and electromagnetic interference”
Every Friday we give away some extra PCBs via Facebook. This post was announced on Facebook, and on Monday we’ll send coupon codes to two random commenters. More PCBs via Twitter on Tuesday and the blog every Sunday. Don’t forget there’s free PCBs three times every week:
Continue reading “Free PCB coupon via Facebook to 2 random commenters”
Frank Zhao shared his simple 6x USB charger with current monitor in the project log forum:
This is a simple 6 port USB device charger with a individual current monitor on each port. The charging current is indicated using RGB LEDs. Blue means slow charge (under 250mA), green means 250mA to 750mA, red means over 750mA, and purple means over 1500mA (for tablets). This circuit involves an ATmega328P (if you do hobby electronics, I bet you have plenty spares of these), INA169 (check out this breakout board), and a OKR-T10-W12.
Via the forum.
Here’s a summary of major developments over the last week. Free PCB Friday is coming up soon.
Coming up:
