Julian Ilett show us how to program the Pro Mini Arduino using a simple USB to Serial adapter. Three USB to Serial adapter are tested here. He writes:
Here I attempt to use 3 different USB to Serial modules to program a clone Arduino Pro Mini. The chips are the FTDI FT232RL, the Silicon Labs CP2102 and the Prolific Technologies PL2032HX.
Arduino USB-to-Serial Tutorial – Programming the Pro Mini - [Link]
Super cheap way to make a dummy load for testing high power PSUs.
Dummy load in a bucket - [Link]
Weiss build a Stepper motor controller to make it easy to test out variety of stepper motors. Just connect power and the motor and you are ready to go. He writes:
The idea is to make a quick and simple tool to test stepper motors and mechanical assemblies such as stepper driven gearboxes and linear activators.
Just hook up whatever power supply (between 8 and 24V, AC or DC) you have lying around to the screw terminals or the barrel jack connector and whatever stepper driven device you have to the motor out pin header or screw terminal and you are ready to go.
Easy Stepper Motor Controller - [Link]
This is a great credit card sized business card and gaming console based on Arduino.
The primary trick of this design is having milled cutouts made for surface mount components to be press fit into, using the circuit board as a kind of frame. Components selected have a thickness near that of the circuit board (1.6mm). Furthermore, to minimize the board thickness, the Atmega328P is inverted so that the bulk of its height below the surface. The result of equal thickness and recessed installation provides a flush appearance. The primary benefit beyond the aesthetic quality is the device is easily slid from a wallet. The high quality boards and the excellent service from oshpark also makes this build possible.
Arduboy: The Interactive Digital Business Card - [Link]
by Hua (Walker) Bai:
The meaning of the term “high power LED” is rapidly evolving. Although a 350mA LED could easily earn the stamp of “high power” a few years ago, it could not hold a candle to the 20A LEDs or the 40A laser diodes of today. High power LEDs are now used in DLP projectors, surgical equipment, stage lighting, automotive lighting, and other applications traditionally served by high intensity bulbs. To meet the light output requirements of these applications, high power LEDs are often used in series. The problem is that several series-connected LEDs require a high voltage LED driver circuit. LED driver design is further complicated by applications that require fast LED current response to PWM dimming signals.
Design Notes: 60V, Synchronous Step-Down High Current LED Driver - [Link]
mcuoneclipse.com explains how to use the HC-06 Bluetooth Module. They write:
After my first post using a Bluetooth module, things have evolved a bit. The challenge with these Bluetooth modules is: they look the same, but having different firmware. I did not fully realize that until I have ordered another bluetooth module from dx.com: That module comes already on a carrier, so I assumed I can use the same driver as for my other module. I was wrong :-(.
HC-05 or HC-06
My earlier module which I received from another source (without an adapter, see this post) has a different firmware on it, known as HC-05, while my DX.com module has a HC-06 firmware. To be clear: the modules are the same, but the software/firmware on it is different, and the firmware uses the pins differently too
Using the HC-06 Bluetooth Module - [Link]
“Applied Science” teardown a commercial, handheld breathalyzer and discuss how it works, then test a standalone ethanol sensor.
How a breathalyzer works (alcohol sensor) - [Link]
Long term reliable contact without interference, creaking and hum, moreover in a beautiful coat – these are the Neutrik / Rean connectors.
Connectors have in general one interesting feature – there are many similar or almost the same connectors on the market. Audio connectors are not exception in this. Even though they look the same, many times there are huge differences in price and mainly in quality. If we supposed, that every producer designs and makes his products likewise responsibly, then the cheaper one should be probably a good choice. Naturally, in praxis it isn´t so.
A real difference between a quality and a low-class connector can be known only at a close-detail investigation and comparison, and ideally after a real testing in praxis.
Quality audio connector must be made of quality materials and also with a high precision. Naturally, if a producer wants to achieve success on a market, it´s often simply impossible to use a too expensive connector, which would over-price the whole device.
That´s why you can find in our store the Neutrik / Rean connectors offering a high-end class for a very reasonable price. Company Neutrik specializes already for almost 40 years in audio connectors and in general connectors for audio/ video studios, equipment of concerts (backstage) and similar, that´s why also in loudspeaker connectors, power supply, Ethernet,…
In the Neutrik products can also be found connectors Rean representing even more affordable price level while maintaining a very high quality. Already a short look at details of Neutrik/ Rean connectors will tell us, that we´re dealing with precision connectors. A matter of course is a detailed documentation with an exact description of electrical features and materials used. A comprehensive overview about available types will give you the Rean catalogue and the Neutrik catalogue (22MB). To many sophisticated connectors like for example NYS373 there are also available assembly instructions.
Uncompromising quality audio connectors for a compromising price - [Link]
The ring counter is useful in hardware logic design such as Application-Specific Integrated Circuit (ASIC) and Field-Programmable Gate Array (FPGA). The ring counter is also ideal in creating simple finite state machines.
The diagram is a circuit of a 4-bit twisted ring counter which can function in 4 different modes, namely: Serial-Input-Serial-Output (SISO), Serial-Input-Parallel-Output (SIPO), Parallel-Input-Serial-Output (PISO), and Parallel-Input-Parallel-Output, by applying Qo to the serial input, the resulting circuit will be a twisted ring or a Johnson Counter. Twisted ring counters are shift registers where the output from the last flip-flop becomes the input of the first flip-flop; it will result in a closed loop circuit which recirculates the data bits around a continuous loop for every sequence state.
The circuit is composed of NAND gates, flip-flops, voltage sources, and clocking system. The NAND gates are incorporated in a Quad-2 input NAND Gate integrated circuit with part number 74ABT00D. The NAND gates receive the inputs from D0, D1, D2, and D3. This device is fully specified for partial power down applications using IOFF. The IOFF circuitry disables the output, preventing the potentially damaging backflow current through the device when it is powered down. The circuit also uses JK flip flops as the memory element. For this circuit, the dual JK flip-flop IC with part number 74HC109D is used. Two 74HC109D chips are used since the circuit needs four JK flip-flops and each IC has two JK flip-flops in it. The 74HC109 is a dual positive-edge triggered, JK flip-flops with individual J, K inputs, clock (CP) inputs, set (SD) and reset (RD) inputs; also complementary Q and Q outputs. The set and reset are asynchronous active LOW inputs and operate independently of the clock input. The supply voltages used to power the ICs are set at 5V for 74ABT00D IC and -1.5V for the 74ABT00D IC. The clocking system connected to the flip-flops provide synchronization pulses and timing for the circuit.
- 74ABT00D Quad-2 input NAND Gate
- 74HC109D Dual Positive-edge triggered JK flip-flops
- Clocking system
- +5V DC Voltage Source
- -1.5V DC Voltage Source
4-bit Twisted Ring Counter using JK Flip Flops – [Link]
What effect does your multimeter input impedance have on the circuit you are measuring? Dave shows a practical example of how it can really screw things up if you aren’t watching out for it.
EEVblog #584 – What Effect Does Your Multimeter Input Impedance Have? - [Link]