Sensor modules project

in project logs, sensors by DP | 0 comments


Elpis shared his sensor modules in the project log forum:

On the PCB you will find a clear indication for the voltage range, the sensor name for quick searching, the read and write I2C addresses together with the pin out labeling. On top of those, a graphic representation of the sensor measuring values gives a better understanding of what you should expect as an output.
For now, I’ve made sensor modules for the MPU6050 sensor (3-axis gyroscope, 3-axis accelerometer, temperature sensor), the SHT10 sensor (humidity, temperature) and the HMC5883 sensor (3-axis magnetometer, compass). Hopefully more ICs will get this treatment soon!

Bus Pirate v3.8 free PCB build

in builds by DP | 0 comments


B-tronics built a free Bus Pirate v3.8 PCB.  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.

Posted in builds | Tagged , | Leave a comment

Steam turret tank R/C controller

in DIY, PIC by DP | 2 comments


An instructable for a PIC based R/C servo controller by Steamhobby:

The controllers capture the R/C receiver output, optionally manipulate the samples, then regenerate new servo control signals. As such, they greatly enhance what is possible with cheap servos.  They were created for my Steam Turret Tank Instructable.

Via the contact form.

Check out the video after the break. Continue reading →

Posted in DIY, PIC | Tagged , | 2 Comments

App note: ESD and EMC sensitivity of IC

in app notes by DP | 0 comments


A good beginner app note (PDF) from NXP on protecting ICs from ESD.

Integrated circuits are sensitive to electrostatic discharge (a sudden and short-time flow of currents) and electromagnetic fields (at which they can be source or victim of both of it). This application note shall be understood as an introductive basic description of what electrostatic discharge is, how sensitive devices can be protected against electrostatic discharges, what electromagnetic compatibility means and how electromagnetic sensitivity can be tested.

Posted in app notes | Tagged , , , | Leave a comment

App note: Power losses and junction temperatures on parallel Schottkys as secondary rectifiers in flyback adapter

in app notes by DP | 0 comments


Parallel Schottkys performance over single Shottkys app note (PDF) from NXP

This document gives an overview of power losses and the consequential junction temperature rise of two parallel Schottkys as secondary side rectifiers in flyback power adapters with up to 12.5 W output power. The focus is set on a comparison of the parallel configuration to a single rectifier under full load conditions. SPICE and thermal simulations were performed to calculate electrical power losses and the rise of junction temperatures above ambient.

Posted in app notes | Tagged , , | Leave a comment

Project: extracting and geographically plotting DTRS site information

in digital radio data, RF by the machinegeek | 0 comments

Lui Gough has been researching the Australian railroad system’s new digital radio system and has posted detailed observations:

As a radio enthusiast, and highly observant public transport user, I’ve made many notes about the deployment of the new Digital Train Radio System (DTRS) sites. This new system is based upon GSM-R in the 1800Mhz band, and is intended to replace the end-of-life Siemens Metronet analogue/digital hybrid trunked network that is currently in use and installed in 1997. From what I’ve been told, Huawei base stations are being used for the deployment.

For details visit Lui’s TechZone blog.

DIY bluetooth door lock

in DIY, hacks by DP | 2 comments


An open source bluetooth door lock check out  the step by step tutorial here at Make:

To open the lock, we will use the app LightBlue. It has a section called the Sandbox, that lets you control the LightBlue Bean without having to program your own iOS app. When the LightBlue Bean receives a serial message, it checks the bytes received against the keycode saved inside the sketch. If the keycode matches the buttons pressed in the sandbox, the Bean Lock will unlock or lock. Get the code from GitHub.
Also, remember to add a pincode to your Bean to prevent other people from reprogramming it.

Via Hacked Gadgets.

Posted in DIY, hacks | Tagged , | 2 Comments

Bitx20 V3 “Dead bug style” new bandpass filter

in DIY by DP | 0 comments


A Bitx20 band pass filter from Pa1ed:

the bandwith of my bandpass filter in the Bitx 20 was very small.Only 100KHz or so.I found this filter on the internet,and after I,ve build the filter I found out that this was the filter used in the Bitx20A from Hendricks QRP kits.Because I wanted to use the whole 20M band (14.000MHz-14.350MHz) I,decided to build the Original bandfilter which was designed in the Bitx20 V1 by Ashar Farhan.

Via Soldersmoke.

Check out the video after the break. Continue reading →

Posted in DIY | Tagged , , | Leave a comment

ESP8266 WiFi chip module

in components, RF, site, wireless by the machinegeek | 1 comment

esp8266 logo
Richard Sloan writes in to highlight his site featuring info on the ESP8266 WiFi module.

There is a new IC on the market that is creating a lot of stir, ESP8266 very low cost WIFI chip, available are boards now from China for $5 or less, we are supporting these new IC over at and thought you might want to get the word out. We do not sell anything and run the site for free.

Via the contact form.

Posted in components, RF, site, wireless | Tagged , | 1 Comment

Measure brightness in Lux using BH1750 sensor on Spark core

in library by DP | 0 comments


Davide Gironi writes:

A library for the BH1750FVI IC.
The BH1750 IC is a light intensity sensor module with built-in a 16 bit AD converter generating digital signal. With the BH1750 Light Sensor intensity can be directly measured by the luxmeter, without needing to make calculations. This library provides function to measure lux through I2C on a Spark Core.

Code is available on GitHub.

Posted in library | Tagged , | Leave a comment

PiGateway upgraded to MightyBoost

in R-Pi by DP | 4 comments


Felix of LowPowerLab writes:

Enter MightyBoost – a multi purpose PSU that can supply the power a Pi needs, and also be controllable by a Moteino (including wirelessly controllable if needed) such that it would duplicate the functionality of ATXRaspi. And most importantly to be able to run it on battery backup in case power is lost, to avoid SD card corruption and downtime. Also it can monitor the battery (via Moteino A7) and shutdown the Pi in time before the battery runs out, as a last resort. Without a Moteino it can be used as a general purpose 5V boost-from-lipo power supply, that can also charge your tablet/iPhone/droid/etc.

I have now upgraded my Pi gateway to using MightyBoost. I had to lasercut a new mid layer for my existing Pi Gateway lasercut case…

Posted in R-Pi | Tagged | 4 Comments

#FreePCB via Twitter to 2 random RTs

in Free PCBs by DP | 0 comments

KHOS-2-3-4-5-6P Every Tuesday we give away two coupons for the free PCB drawer via Twitter. This post was announced on Twitter, and in 24 hours we’ll send coupon codes to two random retweeters. Don’t forget there’s free PCBs three times a every week:

  • Hate Twitter and Facebook? Free PCB Sunday is the classic PCB giveaway. Catch it every Sunday, right here on the blog
  • Tweet-a-PCB Tuesday. Follow us and get boards in 144 characters or less
  • Facebook PCB Friday. Free PCBs will be your friend for the weekend

Some stuff:

  • Yes, we’ll mail it anywhere in the world!
  • Check out how we mail PCBs worldwide video.
  • We’ll contact you via Twitter with a coupon code for the PCB drawer.
  • Limit one PCB per address per month please.
  • Like everything else on this site, PCBs are offered without warranty.

We try to stagger free PCB posts so every time zone has a chance to participate, but the best way to see it first is to subscribe to the RSS feed, follow us on Twitter, or like us on Facebook.

DIY small bench power supply

in DIY, power supply by DP | 0 comments


newtonn2 posted detailed instructions of how to make this DIY small bench power supply that can adjust with precision current or voltage:

After making my Mini Adjustable Power Supply I was very happy with it, but I was missing a more accurate control of the voltage and current. So I decided to make this slightly bigger (but still small) bench power supply.

The heart of the unit is basically the same as on the other power supply. It is based on the LM2596S. This IC can handle up to 3A with a good heat sink. I would use it only for 2A to be on the safe side.

Check out the video after the break. Continue reading →

Frequency counter with PIC16F628A

in DIY, PIC by DP | 9 comments


xristost blogged about the frequency counter module he made:

First of all I wanted a PIC microcontroller to do the whole job without any additional ICs. Also I wanted to use the the familiar 16F628A, but because one of the portA pins (RA5) can be used only as input I was short of outputs to do the job. Driving 6 digit 7-segment multiplexed display requires 7 + 6 = 13 outputs. The 16F628A has 16 IO pins, two of which are used for the crystal oscillator, one is for the signal input and other one can be used only for input, that leaves us with only 12 useful IO pins. The solution was to drive one of the common cathodes with a transistor, which opens when all other digits are switched off.

APA102 aka “Superled”

in LEDs by DP | 4 comments


cpldcpu writes:

I contrast to the very timing-sensitive one-wire protocol of the WS2812, the APA102 uses a standard two wire SPI protocol – one clock line and one data line. Each LED has two inputs and two outputs which can be daisy chained. At the first sight this may seem wasteful, but it has the advantage of being supported by standard microcontroller periphery and it is insensitive to timing variations. Due to the critical timing requirement it is not possible to control the WS2812 from SOCs with multitasking operating systems, such as the Raspberry Pi. This should not be an issue with the APA102. Furthermore, the data can be transferred at an almost arbitrary clock rate. I was able to control the LEDs with 4 MHz SPI clock without any hitch. It appears that the maximum speed is mainly limited by the parasitics of the wiring.

Posted in LEDs | Tagged , , , | 4 Comments

Motor controllers for cheap robots

in DIY, robotics by DP | 2 comments


An instructables on motor controllers for cheap robots  by JayWeeks

Almost every robot needs to power a motor of some sort or another. Problem is that motors take quite a lot of power, compared to what most microcontrollers operate with. To solve this problem, robots use what is called a motor controller, which usually amounts to some form of electronic switch that can turn on a very high voltage, using a very low one. That’s what we’ll be making today!