Ralph Doncaster writes: In virtually all of my micro-controller projects, I’ll use 0.1uF ceramic capacitors between Vcc and Gnd. Depending on the power draw of the MCU and inductance on the power lines, they may not be necessary, at a cost of a penny or less each there’s little reason not to use them. I […]
Category Archives: how-to
Using a USBASP v2.0 as a cheap ATmega8 Arduino platform
JohnLittle writes: I finally got round playing with my AVRASP v2.0 boards. The ones Sleepwalker3 mentioned. Thanks mate! I bought three USBASP v2.0 on ebay for under £1.50 each. They each came with a short cable (5×2 sockets at each end). However, they do not come with the JP2 header soldered on. Solder it or […]
Wireless servo controller II
Ondřej Karas of DoItWireless writes: We described simple method, how to drive modellers servo. Today, we are going to try to drive this servo from potentiometer connected to TR module ADC. It is reaction to forum thread where is discussion about airplane model control possibility. Check out the video after the break.
Dirty DIY stencils
Matt Mets of Blinkinlabs shared a tutorial on making solder paste stencils quickly by hand: This is a truly quick and dirty method for making solder masks, and is nice because it only requires a few hand tools. It’s great for situations when you want to test a new design or make a single, small […]
A 5c lithium ion battery charger
Nerd Ralph writes: As various sites explain, lithium-ion rechargeable batteries should be charged to 4.2 volts. USB ports provide 5V, so all I needed was a way to drop 5V down to 4.2 or less. Standard diodes have a voltage drop of 0.6 to 1.0 volts, so I pulled up the datasheet for a 1n4148, […]
ST-Link/V2 SWD-JTAG adapter
alexwhittemore has posted a detailed tutorial how to make an adapter: ST-Link/V2 SWD-JTAG adapter The fantastic STM32 Discovery boards from ST Micro all come with an embedded ST-Link/V2 debugger onboard, including some jumpers to disconnect it from the target device for use as a standalone SWD debugger. Presumably, this is to allow for easy use debugging […]
How to hack a manual control into a cheap DMX dimmer
This article shows how to hack a manual control into a cheap DMX dimmer by Miceuz and Rxdtxd of wemakethings; One of our friends wanted to have a manual-control LED dimmer for his stop motion setup. We had several of these cheap Chinese DMX dimmers. How does one adds potentiometer control to something like this? Just cut […]
Hand powered USB charger from hacked IKEA flashlight
Werner sends this handy hack he found at IKEAHackers. Giovanni Gentile devised this simple hack which mods an IKEA Ljusa hand powered flashlight into a USB charger. “The procedure was simple, it was enough to eliminate some resistors and use a capacitor sufficient to handle the charge given by the Ljusa’s dynamo. I set the […]
Interfacing the STM32VLDISCOVERY with Semtech’s SX1272RF1BAS module
Milen Pavlov with Netblocks wrote this post on connecting a STM32VLDISCOVERY with Semtech’s SX1272RF1BAS module (LoRa sx1272 transceiver.) This module incorporates the LoRa spread spectrum modem which is advertised as achieving significantly longer range than existing systems based on FSK or OOK modulation. It operates using low power in the ISM bands. Milen’s article includes […]
Programming an ATMega128
Chris Holden of NerdClub shares his tips on how he successfully program an ATMega128: Finally got an ATMega128 chip coded and programmed successfully. The great news is it doesn’t require Arduino. The even better news is, we can use Oshonsoft to write the code! Yay.
Attiny25/45/85 police light with Arduino
Another Instructables by Jan Henrik, a police light with a Attiny25/45/85. He writes: Hello, in this project I want to show you how to build a multi functional Police Light with a Attiny25/45/85 . It will have serval animations , which can be changed with a button on the circuit board, it has 2 channels, […]
Arduino based waveform generator
Hemal Chevli made this Arduino based waveform generator. He wrote a post on his blog detailing its assembly: Finally, after sitting in the TODO list for a long time, I’ve made a basic wavefrom generator based on arduino, made using this instructable as reference. I had an enclosure laying around which has incorrect dimensions for […]
Naze32 on Mini quad setup quadcopter
Oscar Liang wrote a post on his blog detailing how to setup a Naze32 Flight contoroller on his mini quad: I have finally decided to swap out the KK2.1.5 with the Naze32 on my FPV250 mini quad. I have to say IMHO after a couple of test flight, the Naze32 Flight controller does perform better […]
Simple xtal oven for accurate clocks
From the comments on our earlier HP 5350B OCXO repair post, a temperature controlled OCXO xtal oven: This is a very simple and easy to make temperature controller and heater to be attached to a xtal (crystal). The xtal is normally used to clock a microcontroller (PIC or ATMEL etc). Normally xtals provide an accurate clock to […]
Linux security tip: moving your /boot partition to removable media
Today threats to your data can come from many quadrants. It’s not enough to protect against malicious online attacks; there’s the very real threat of government confiscating and examining the electronic devices carried by international travelers, and even planting spyware. In this post from “The Doctor”, we’re shown one way to mitigate this threat, which […]
Control a camera flash using TTL signals
Control a camera flash using TTL signals by Hemal Chevli So finally bought a new flash, and powered up, I used one of my keys to shot the pin and base plate and IT WORKED! Next I measured the voltage between centre pin and base pin, it was 5V. Things were simple from this point, pulled out […]
Debricking Seagate Dockstar
ZsZs documented his Dockstar debricking with the Bus Pirate: Somehow I managed to brick my Dockstar. It was so simple like the first sentence :) The debricking process was quite long due to lack of experience and tools. Tools required: – A buspirate card (I have a v3.6) – openocd with buspirate support – An […]
Mini Quad – build a FPV250 mini-H quadcopter
Oscar Liang built a FPV250 mini-H quadcopter and wrote a post on his blog detailing it’s assembly: Having built a mini quad before running on 2S, although it was very easy to control and stable, I was not particularly happy with the power. I cannot fly too fast, neither doing flips and acrobatics. This time I will be using […]
850 MHz scanner preamplifier / filter project
KF5OBS writes: This article shows how to use off-the-shelf parts to improve the performance of a radio scanner in the 800 – 900 MHz band. Furthermore, it shows how to expand radio coverage by using two different receive antennas at the same time. For some reason, my new BCD996XT scanner wasn’t working as expected on […]
Simple LED driver/constant-current source 20 mA
Another Instructable by Jan Henrik, a constant-current source which gives 20mA at the output. He writes: It is a circuit, which limits the current to 20mA, what allows us to drive any normal led, without calculating a resistor, you can just plug the led in and see it emitting light… Also this allows us to test […]