AntzyP @ instructables.com writes:
Cap’n ArrDrownHo! is the lovechild of Ardweeny and Boarduino and he’s here to commandeer your AVR ships. ArrDrownHo! inherits pros of both and cons of neither. Pick up an AVR chip and start prototyping instantly on a breadboard! Want to replace that costly Arduino in your project with a cheap AVR, but don’t know how? Use the simple plug-and-play ArrDrownHo! piggybacked onto the AVR to act as interface for programming and provide power.
ArrDrownHo! – Easily convert AVR to Arduino - [Link]
Niek designed this BareDuino micro, that is available at github:
For some Arduino projects, you don’t actually need that many IO pins. That’s exactly the case when I tried to build a simple RGB throwie that would cycle through colours. I was looking for a cheaper alternative to the Arduino UNO’s ATmega328P when I stumbled across this post by MIT’s High-Low Tech lab. They developed a library for programming the 8-pins ATtiny45/85 from the Arduino IDE. It’s a very smart solution to use permanently in some low pin-usage projects, but you still need to hook up individual wires from your programmer to the ATtiny to be able to program it. That’s when I came up with the idea of the BareDuino Micro.
BareDuino micro - [Link]
This is a flyback SMPS that will boost voltage a voltage of around 20V to 40V, or more if you change the feedback resistors. It uses an off the shelf transformer from CoilCraft. The LM3479 is a nice controller because it’s frequency of operation can be set by changing R1. At 39K it runs at about 500KHz.
Flyback Switch Mode Power Supply Circuit - [Link]
When the circuit is powered up, all of the transistors are off and stay off. C1 gets pulled up to Vp. When the switch is pushed, Q3 and Q2 turn on, since their base is pulled up. Q1 and Q4 are in turned on as well. Q1 keeps Q2 turned on and Q2 keeps Q3 turned on and Q3 keeps Q4 turned on. Q4 supplies current to the load. When Q2 is asserted it keeps pin 1 of SW1 at ground.
When the switch is pulled low again, the base of Q3 is tied to ground, because Q2 is on, and the chain is broken an all of the transistors turn off.
C1 and R1 and R5 form the time constant for the debounce circuit. Adjust these values for an appropriate debounce time.
Latching Momentary Switch for breadboard - [Link]
MegunoLink Pro is a tool designed to aid embedded electronics designers. From hobbiests using the Arduino platform to commercial engineers using PIC or TI micros. MegunoLink provides a set of tools to help visualize serial data and investigate what is going on inside that piece of silicon. MegunoLink is made up of a set of visualizers that each have a unique function and any number of them can be utilized at once. With these visualizers and our functional tabbed and docked interface you can create a full control center for your embedded project. Plot, log and monitor serial streams from both hardwired, bluetooth, and network based (UDP) devices.
MegunoLink Pro – Visualize serial data of your mcu with ease - [Link]
DIY Goodies show us a way to make flat vias for your PCB projects. diygoodies.org.ua writes:
Catching up the development of printed circuit boards at home i often faced with the problem of “the bulbous” vias. Usually homemade double-layer boards soldering from both sides with the thin wire, the result usually satisfied but if you need to make VIA under the chip TQFP48, SOIC16 and that’s is a real problem, if contact is very bulbous it will be simply impossible cleanly solder chip as its legs will hang in the air.
DIY PCB with flat VIA’s - [Link]
Now and again there’s a need to expand the I/O capabilities of your chosen micorocontroller, and instead of upgrading you can often use external parts to help solve the problem. One example of this is the 74HC4067 16-channel analog multiplexer demultiplexer. That’s a mouthful – however in simple form it’s an IC that can direct a flow of current in either direction from one pin to any one of sixteen pins. Another way to think abou it is that you can consider the 74HC4067 to be a digital replacement to those rotary switches that allow you to select one of sixteen positions.
74HC4067 16-Channel Analog Multiplexer Demultiplexer - [Link]
Alex Sidorenko writes:
From time to time many of us are facing the same problem when trying to charge your smartphone or tablet from the USB port – it just not charging. Recently I have bought USB car charger to power my Samsung Galaxy Tab 10.1 on the road just to discover it doesn’t work. Even though the Galaxy actually sees the charger connected is just marking it as unrecognized power source. I was trying to power up my Motorola Droid 3 phone – it won’t work either. The reason is simple – the Galaxy Tab doesn’t recognize the charging device as “native charger”.
What is “native” charger?
The native charger for smartphone or tablet often have a special voltage signature on USB data pins to let the device recognize the charger and figure out the maximum charging current it can consume from the power source. The intent is twofold. First, it is stopping the device from consuming too much current from the charger. Second, it is preventing the charging from unrecognized power sources. The “unrecognized” is the keyword here, as profiting from selling additional device accessories (chargers) is definitely a business strategy.
Charging your Smartphone from USB without fear - [Link]
LEDger Led (polarity) tester:
Everytime I solder a SMD LED on a pcb I have to turn on one of my multimeters and flip it over to diode-test mode and then probe the SMD LED to see which connector is the anode and which is the cathode. The LEDger is a small PCB with a button cell battery and smd footprints that allows me to, while still holding the LED in my tweezers. just hold it onto one of the footprints and see if it lights up or not.
LEDger Led (polarity) tester - [Link]
Travis Goodspeed has been experimenting with remote satellite tracking over the internet. His setup uses a satellite dish originally used with a mobile earth station on maritime vessels. Movement of the dish is accomplished with servos and an EiBotBoard wired into a BeagleBone. Travis writes:
My initial build using an RTL-SDR dongle. Data processing is done on my server, with the BeagleBone forwarding data from rtl_tcp. To avoid offending the FCC and ham radio operators everywhere, I disabled the dish’s 1.5GHz transmitter and use only the 1.6GHz downlink antenna. If I can justify the extra weight, I’d like to drop the RTL-SDR in favor of a USRP2 over Gigabit Ethernet in order to get greater bandwidth and sensitivity.
Tracking low earth satellites using RTL-SDR - [Link]