Everytime we need to test a stepper motor controller we have to connect it to the parallel port of the computer or to a function generator to obtain the necessary pulses the realize the movements of the stepper.
This is a quicker method to check a controller integrity. Simply to make the life easier here is a square wave signals generator. A potentiometer or a trimmer regulates the pulse generation of the 12F675 microchip (a square wave, between 20 hz and 3khz). Ok, there are thousands of different ways to create a pulse generator, but we had a lot of microcontrollers.
12F675 pulse generator - [Link]
by Henrik’s Blog @ hforsten.com:
Ionizing radiation is something that almost anyone finds exciting (or scary) and I’ve also been for long wanted to build a Geiger counter. Unfortunately Geiger tubes have usually been too expensive to seriously consider buying them just for a hobby project. But I found out that sovtube sold soviet cold war era Geiger tubes only for a couple dollars. I bought one CI-22BG tube and one CI-3BG tube for total of 16€ including shipping from Ukraine to Finland. The site itself didn’t really convince me payment via Paypal failed because of invalid seller email address and gmail warned me that order confirmation e-mail might not have come from the address it claimed. However, I got both of the tubes and they seemed to be okay.
DIY Geiger counter - [Link]
An application note from Texas Instruments, A single-supply Op-Amp circuit collection (PDF!):
There have been many excellent collections of op-amp circuits in the past, but all of them focus exclusively on split-supply circuits. Many times, the designer who has to operate a circuit from a single supply does not know how to do the conversion.
Single-supply operation requires a little more care than split-supply circuits. The designer should read and understand this introductory material.
A single-supply Op-Amp circuit collection - [Link]
Watch signals propagate through basic digital circuits. Emulate any two-input logic gate using just one rLogic board and one jumper. To order rLogic+, the breadboard compatible variant, simply order normal rLogic. When the survey is sent out you will indicate which you would like.
rLogic is a basic breakout board for the Fairchild Semiconductor TinyLogic® series of Configurable Logic Gates, with an LED for watching signals and cleverly arranged header pins for simple conversion from gate to gate. Different from programmable logic, configurable logic is manually changed through rewiring using a simple shunt (AKA, a jumper), allowing you to easily and quickly morph a single pinkie sized board into any basic logic function you might need. rLogic requires no prior knowledge, but if knowledgeable of basic digital circuitry then you may jump right in with creating. If not, then a few minutes with rLogic boards will begin to teach you the basics of digital electronics.
rLogic: Affordable, Tiny, Universal Logic - [Link]
I had think of making a game on Arduino quite a while. An idea strikes to my mind while I was playing a quite popular game which is available on apps and pc, 2048. 2048 is actually a game created by Gabriele Cirulli, aged 19, Itallian web developer. The objective of this game is to slide the tiles and combine them to create the tile of 2048. Source: Wiki
This game can be quite addictive and challenging which also makes me thought of how the game works. You can play the pc version at http://gabrielecirulli.github.io/2048/. Then I took some time to figure out the basic of idea of the game operation, so that I can make one on Arduino. Isn’t it cool to create it on Arduino and create a different playing platform?
2048 on Arduino - [Link]
RS Components just announced the availability of Raspberry Pi Model B +.
After the success with Model B, three million items sold, Raspberry Pi has been enhanced with several new features and functions included in the Model B + version. Apparently:
the energy consumption of the Pi Model B+ are significantly lower (between 20% and 30% less than the B)
I / O lines have been expanded replacing the GPIO socket with one for 40-pin connectors (pinout for the first 26 contacts remains identical to that of the original Model B)
The number of USB ports is doubled from two to four
The new Raspberry B+ is here for RasPi lovers - [Link]
The ULN2003A 7-way (or ULN2803A 8-way) darlington driver is usually the go-to chip of choice when you need to switch any high current load from a microcontroller’s GPIO. It provides seven darlington driver stages to give low-side switching and even includes seven common-cathode clamp diodes to snub voltage spikes when high inductance loads are used. Texas instruments have recently introduced an alternative device which is said to be the industry’s first seven-channel, NMOS low-side driver chip.
The TPL7407L is a high-current NMOS transistor array. It contains seven NMOS transistors that feature high-voltage outputs also with built-in clamp diodes. The input stage is compatible with GPIO logic levels ranging from 1.8 to 5.0 V and the maximum rating of each NMOS channel is 600 mA. Several outputs can be paralleled if it is necessary to sink higher levels of load current. The TPL7407L’s key benefit is its improved power efficiency and lower leakage compared to bipolar darlington drivers.
Efficient NMOS Driver Array - [Link]
by Henrik’s Blog @ hforsten.com:
Nowadays many of the most “exiting” chips come only in leadless packages, such as BGA and QFN which are hard or impossible to solder just by soldering iron, because leads are under the chip where they can’t be reached. These kinds of chips are usually soldered using reflow soldering. In reflow process solder paste is used instead of solder wire. It contains very small balls of solder in flux, diameter of the balls is just few micrometers. First this paste is put on the contact pads, then components are placed on the pads and whole board is heated in reflow oven where solder balls in the paste melt and attaches the components firmly in place.
Toaster oven reflow controller - [Link]
Discovering of overheating and joints with a high resistance has never been easier and safer. With the type Flir i3 now moreover price-affordable.
Thermal cameras, i.e. cameras sensitive in infrared range bring a useful information – picture with virtual colors responding to a temperature of a scanned surface. Maybe, at the word “thermal camera” you too get an idea about a well known usage in buildings – inspection of a heat leakage (thermal bridges) = status of a thermal insulation of buildings. But that´s only one of many ways to use these devices. In electronics and power engineering it´s far more interesting for example:
- searching for faults on a PCB, optimizing of layout in respect to an even heat distribution
- inspection of distribution boxes with cables, terminal blocks and circuit breakers
- inspection of motors and transformers
- inspection of cables interconnections (overheating caused by a high resistance)
- inspection of cooling efficiency – heatsinks, fans, …
- inspection of solar panels
…and all this at full operation and under (often high) voltage.
„I have an infrared thermometer, thus I need no camera” – this is a frequent opinion – until the time, you once try working with a camera. The joke is, that one picture from for example camera Flir i3 with resolution of “only” 60×60 pixels equals to 3600 measurements of an IR thermometer. It can be said, that one picture taken by the camera even exceeds 3600 measurements (done by an IR thermometer), because a spatial resolution of the thermal camera is usually better (surface measured by one pixel is smaller) than that of IR thermometers. This way it can happen, that a small source of heat (for example a small overheated component) can´t be discovered by an IR thermometer, while with a camera it will be clearly visible. Naturally, there are many applications where only an IR thermometer is sufficient, but cameras are far better for a professional usage and a maximum work efficiency.
That´s why we decided to incorporate into our offer the world renowned cameras from company FLIR, which is on the edge of development in this segment. As a standard stock item can be found type Flir i3 (3600 px) with resolution of 0.15°C and a viewing angle 12,5°x 12,5°. Big 2,8“ TFT display shows all necessary information and settings. Very advantageous is a possibility to store up to 5000 snapshots into a uSD card (2GB, jpg) and a consequent transfer of files into a PC through a USB. Further detailed information will provide you the Flir i3 datasheet.
Upon order we´re able to supply you any other type from company FLIR in a short leadtime..
Even hidden faults can be found with FLIR thermal cameras - [Link]
by Henrik’s Blog @ hforsten.com:
All of the best integrated circuits today come in hard to solder BGA packages. Because BGA packages have connections under the chip soldering is harder and it needs to be done using a reflow oven or hot plate. Another problem is with designing the PCB, vias and traces need to be small enough to fit between the solder balls and there needs to be usually quite many layers in the board to make room for all the closely packed traces. This means that a cheap Chinese two layer board doesn’t have enough room and more layers are needed. Adding layers increases the cost of the board dramatically when ordering only a few copies.
Making embedded Linux computer - [Link]