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How VoIP technology Works – free phone calls
Jul 7th
If youve never heard of VoIP, get ready to change the way you think about long-distance phone calls. VoIP, or Voice over Internet Protocol, is a method for taking analog audio signals, like the kind you hear when you talk on the phone, and turning them into digital data that can be transmitted over the Internet.
How is this useful? VoIP can turn a standard Internet connection into a way to place free phone calls. The practical upshot of this is that by using some of the free VoIP software that is available to make Internet phone calls, youre bypassing the phone company (and its charges) entirely.
 This person is using a computer to talk to a friend in another state. |
VoIP is a revolutionary technology that has the potential to completely rework the worlds phone systems. VoIP providers like Vonage have already been around for a while and are growing steadily. Major carriers like AT&T are already setting up VoIP calling plans in several markets around the United States, and the FCC is looking seriously at the potential ramifications of VoIP service.
Above all else, VoIP is basically a clever “reinvention of the wheel.” In this article, well explore the principles behind VoIP, its applications and the potential of this emerging technology, which will more than likely one day replace the traditional phone system entirely.
The interesting thing about VoIP is that there is not just one way to place a call. There are three different “flavors” of VoIP service in common use today:
- ATA — The simplest and most common way is through the use of a device called an ATA (analog telephone adaptor). The ATA allows you to connect a standard phone to your computer or your Internet connection for use with VoIP. The ATA is an analog-to-digital converter. It takes the analog signal from your traditional phone and converts it into digital data for transmission over the Internet. Providers like Vonage and AT&T CallVantage are bundling ATAs free with their service. You simply crack the ATA out of the box, plug the cable from your phone that would normally go in the wall socket into the ATA, and youre ready to make VoIP calls. Some ATAs may ship with additional software that is loaded onto the host computer to configure it; but in any case, its a very straightforward setup.
- IP Phones — These specialized phones look just like normal phones with a handset, cradle and buttons. But instead of having the standard RJ-11 phone connectors, IP phones have an RJ-45 Ethernet connector. IP phones connect directly to your router and have all the hardware and software necessary right onboard to handle the IP call. Wi-Fi phones allow subscribing callers to make VoIP calls from any Wi-Fi hot spot.
If youre interested in trying VoIP, then you should check out some of the free VoIP software available on the Internet. You should be able to download and set it up in about three to five minutes. Get a friend to download the software, too, and you can start tinkering with VoIP to get a feel for how it works.
Next, well look at exactly how VoIP is used.
serial data communication protocol Monitoring – ADC200/20
Jul 7th
This experiment demonstrates how a serial data communication protocol can be successfully monitored. Serial data communications represents the fundamental method by which information is transported in our modern world.
Convergence between communications and computers has caused all forms of information to be digitized for easy transport in serial format. Unlike analog waveforms such as sine waves and square waves that are periodic in nature, serial data comm waveforms are generally aperiodic. Using a modern digital instrument such as the PICO ADC200/20 makes capture and viewing of serial data easy.
This experiment demonstrates:- What serial data looks like.
- Monitoring this data using the PICO ADC200/20 oscilloscope.
- First introductory data communications course for college/university.
- Electronics experimenter such as a amateur radio operator.
Equipment Required:
- ADC200/20 scope, scope probe.
- PC with serial port.
- Terminal program such as Hyperterminal for Win95/98, Terminal Win3.1 or Telix Linux.
Safety
Always keep in mind that the ground of the ADC200/20 is common to the ground of the PC and thus common to AC ground.Experimental Setup
The experimental setup is shown in Figure 1. Serial data is accessed from the serial port on a standard PC. The serial port is generally either a DB9 connector or DB25 connector. Figure 2 shows a picture of a standard PC DB9 type serial port. An appropriate serial cable consisting of female/male DB9 connectors is connected to this port.The ADC200/20 CH A input is connected to the Transmit Data and Ground connections on the serial port via the serial cable. Note that you can use the same PC that the ADC200/20 is connected to for the serial transmission or you can use a standalone PC. Figure 1 shows separate PCs for convenience.
Figure 1 Experimental Setup
Figure 2 Photo of PC Serial Port DB Male Connector
Experimental Procedure
1. Terminal Software SetupOne of the simplest serial data comm protocols is sending ASCII characters via a PC terminal program. Several popular terminal programs exist, depending on the PC operating system (Win95/98, Win3.1, Linux, DOS, etc). Let�s examine Hyperterminal that commonly comes as part of the Win95/98 operating system.
To access Hyperterminal, follow the Start Button:
Start/Programs/Accessories/Communications/HyperTerminal/Hypertrm.exe
Once you have located the Hyperterminal directory, find the Hypertrm program and double click it. The program screen is shown below in Figure 3.
Figure 3 Hyperterminal Screen
Now you must setup the terminal parameters. Under File, locate New Connection. Give the connection the name Picotech and click OK. The Connect To box appears. Select the Connect using parameter to Direct to Com1 (assuming that serial port used is Com1. Check with your PC manual for settings for serial port). Click OK. Next the Port Settings box appears.
Accept the parameters as listed below:
- Bits per sec = 2400
- Data bits = 7
- Parity = none
- Stop bits = 1
- Flow control = hardware
Finally under File, go to the Properties parameter and select the Settings tab. Go to ASCII Setup
and check off the box Echo typed characters locally. Save all settings under Picotech.htm. The terminal program is now setup. The proper settings are shown below in Figure 4.
Figure 4 Hyperterminal Terminal Properties Setup
2. ADC200/20 Scope Setup
Once the terminal program is configured, we are ready to send serial data. The terminal program will send data via the serial port in RS-232 format. Figure 9 shows the pinouts of the DB9 and DB25 type RS-232 connectors commonly found on serial ports.
Connect the ADC200/20 scope probe with the center conductor connected to the Transmit Data Terminal #3 and the ground conductor to Ground Terminal #5. Note this setting is for a DB9 connector. Adjust accordingly for a DB25.
In order to capture the one time asynchronous signal, the scope must be set for one time trigger.
Set the instrument as follows:
- TxData to Input A, +/- 20V, DC, Probe x 1, Input B off
- Time base = 500usec/div
- Trigger = single, Input A, rising, 1000mV, -10% delay
Note that the scope is set to trigger with a rising voltage > 1 volt on input A.
3. Sending Serial Asynchronous Data and Capturing Results
With the Terminal PC we are now ready to send and capture ASCII data. Try sending an ASCII G first. To do this, first set Cap Lock on the keyboard to on. Then simply press G. Ensure that the correct character is sent out, as it will echo on the Hyperterminal display. If you are using the same PC for both Terminal and the ADC200/20 display, you will have to size both windows so that they are visible.
Now in order to capture and display the result on the scope, hit the run button. The scope will now trigger with any voltage rising on input A >1 volt. Press the G again. You should see a display similar to Figure 5 below. Note the cursors have been set to measure the duration of the start bit.
Try another character, say the numeral 8. The display for 8 is shown in Figure 6. Note to clear the display press stop, then run again.
Figure 5 ASCII G As Displayed on ADC200/20
Figure 6 ASCII 8 As Displayed on ADC200/20
Further Questions
- Does the waveform shown in Figure 6 match what should be seen for ASCII 8 ?.
- How wide would a bit be if the data speed was changed to 4800 bit/sec?.
Serial Ports and Digital I/O
Jul 7th
4.1 Serial Communication
In the factory-default configuration, the TCP/IP Development Board has one RS-232 (3-wire) serial channel, one RS-485 serial channel, and one synchronous CMOS serial channel. The TCP/IP Development Board may be configured for 5-wire RS-232 or two 3-wire RS-232 channels. The exact configuration instructions depend on the version of the TCP/IP Development Board you have. This information is etched on the bottom side of the printed circuit board, or you can readily determine your version by examining the diagrams below to find the one that matches your board.
The RS-232 transceiver may be used as a 5-wire RS-232 channel or as two 3-wire RS-232 channels at the expense of the RS-485 channel by adding 0 W surface-mounted resistors at R61 and R62 as shown in Figure 6(a). The RS-485 chip (U10) and the associated bias and termination resistors (R58, R59, and R60) shown in Figure 7 must be removed when configuring the TCP/IP Development Board for either one 5-wire RS-232 or two 3-wire RS-232.
Table 2(a) summarizes the options. Note that the parameters in the serMode software function call must also be set to match the hardware configuration being used.
The RS-232 transceiver may be used as a 5-wire RS-232 channel or as two 3-wire RS-232 channels at the expense of the RS-485 channel, which is connected through 0 W surface-mounted resistors at R82 and R83 as shown in Figure 6(b). R82 and R83, shown in Figure 6(b), must be removed when configuring the TCP/IP Development Board for either one 5-wire RS-232 or two 3-wire RS-232. U10 and the associated bias and termination resistors (R58, R59, and R60) must also be removed, but R82 and R83 are left installed, if you wish the TxB and RxB RS-232 signals to be available on header J5.
Table 2(b) summarizes the options. Note that the parameters in the serMode software function call must also be set to match the hardware configuration being used.
The RS-232 transceiver may be used as a 5-wire RS-232 channel or as two 3-wire RS-232 channels at the expense of the RS-485 channel, which is connected through jumpers across header JP7 as shown in Figure 6(c). The jumper configurations are shown in Figure 6(c).
Table 2(c) summarizes the options. Note that the parameters in the serMode software function call must also be set to match the hardware configuration being used.
4.1.1 RS-232
The TCP/IP Development Boards RS-232 serial channel is connected to an RS-232 transceiver, U11. U11 provides the voltage output, slew rate, and input voltage immunity required to meet the RS-232 serial communication protocol. Basically, the chip translates the Rabbit 2000s 0 V to +Vcc signals to RS-232 signal levels. Note that the polarity is reversed in an RS-232 circuit so that +5 V is output as approximately -10 V and 0 V is output as approximately +10 V. U11 also provides the proper line loading for reliable communication.
The maximum baud rate is 115,200 bps. RS-232 can be used effectively at this baud rate for distances up to 15 m.
4.1.2 RS-485
The TCP/IP Development Board has one RS-485 serial channel, which is connected to the Rabbit 2000 Serial Port B through U10, an RS-485 transceiver. The chips slew rate limiters provide for a maximum baud rate of 250,000 bps, which allows for a network of up to 1200 m (or 4000 ft). The half-duplex communication uses the Rabbit 2000s PC0 pin to control the data enable on the communication line.
The RS-485 signals are available on pins 3 and 4 of header J7, and on J5, the RJ-12 jack.
The TCP/IP Development Board can be used in an RS-485 multidrop network. Connect the 485+ to 485+ and 485- to 485- using single twisted-pair wires (nonstranded, tinned).
Alternatively, the RS-485 multidrop network may be hooked up using cables with RJ-12 plugs. Note that the RJ-12 jack has +RAW_485 and GND, which means that only one TCP/IP Development Board needs to be connected to an external power source via an AC adapter. When doing so, ensure that the AC adapter has sufficient capacity for the network — each TCP/IP Development Board nominally draws 100 mA at 24 VDC.
The TCP/IP Development Board comes with a 220 W termination resistor and two 680 W bias resistors installed and enabled with jumpers across pins 1-2 and 5-6 on header JP6, as shown in Figure 7.
The bias and termination resistors in a multidrop network should only be enabled on both end nodes of the network. Disable the termination and bias resistors on the intervening TCP/IP Development Boards in the network by removing both jumpers from header JP6. Note that older versions of the TCP/IP Development Board do not have this jumper feature, and the surface-mounted bias and termination resistors shown in Figure 7 have to be removed in networks containing more than 10 TCP/IP Development Boards.
4.1.3 Programming Port
The TCP/IP Development Board has a 10-pin programming header labeled J4. The programming port uses the Rabbit 2000s Serial Port A for communication. The Rabbit 2000 startup-mode pins (SMODE0, SMODE1) are presented to the programming port so that an externally connected device can force the TCP/IP Development Board to start up in an external bootstrap mode.
| NOTE | Refer to the Rabbit 2000 Microprocessor Users Manual for more information related to the bootstrap mode. |
The programming port is used to start the TCP/IP Development Board in a mode where the TCP/IP Development Board will download a program from the port and then execute the program. The programming port transmits information to and from a PC while a program is being debugged.
The TCP/IP Development Board can be reset from the programming port.
The Rabbit 2000 status pin is also presented to the programming port. The status pin is an output that can be used to send a general digital signal.
4.1.4 Serial Communication Software
Library files included with Dynamic C provide a full range of serial communications support. The RS232.LIB library provides a set of circular-buffer-based serial functions. The PACKET.LIB library provides packet-based serial functions where packets can be delimited by the 9th bit, by transmission gaps, or with user-defined special characters. Both libraries provide blocking functions, which do not return until they are finished transmitting or receiving, and nonblocking functions, which must be called repeatedly until they are finished. For more information, see the Dynamic C Users Manual and Technical Note 213, Rabbit 2000 Serial Port Software.
The following function calls are specific to the TCP/IP Development Board.
int serMode (int mode); |
- User interface to set up up serial communication lines for the TCP/IP Development Board. Call this function after
serXOpen().
Return Value
See Also
void serB485Tx(); |
See Also
void serB485Rx(); |
See Also
4.1.4.1 Sample Serial Communication Programs
- Connect RX to TX as shown in Figure 8 below.
- Connect the programming cable to header J4 on the TCP/IP Development Board. Apply power to the TCP/IP Development Board.
- Open the sample program
SAMPLESICOMICOM232.Cand press F9.
This program demonstrates a simple RS-232 loopback displayed in the Dynamic C STDIO window.
- Connect 485+ to 485+, 485- to 485-, and GND to GND as shown in Figure 9 below. If you do not have a separate wall transformer for the other board, also connect PWR to PWR as shown in Figure 9.
- Connect the programming cable to header J4 on one TCP/IP Development Board. This will be the slave, the other board will be the master. Apply power to the TCP/IP Development Boards.
- Open the sample program SAMPLESICOMICOM485.C. You will find some code for the master, and some code for the slave. Copy and save the master and slave versions separately.
- Open the sample slave program and press F9.
- Connect the programming cable to header J4 on the master TCP/IP Development Board.
- Open the master program and press F9.
This program demonstrates a simple RS-485 transmission of lower-case letters to a slave. The slave will send back converted upper case letters back to the master, which then displays them in the Dynamic C STDIO window.
4.2 Digital I/O
4.2.1 Digital Inputs
Pins 8-11 on header J7 have the four digital inputs IN0-IN3. Each of the four digital 0 V to 5 V inputs is protected over a range of -36 V to +36 V. The TCP/IP Development Board is factory-configured for the digital inputs to be pulled up to +5 V, but the digital inputs can also be pulled down by moving the surface-mounted jumper at JP4. The jumper settings and the location of JP4 are shown in Figure 10.
4.2.2 Digital Outputs
Pins 12-15 on header J7 have the four digital outputs OUT0-OUT3. Each of the four open-collector digital outputs can sink up to 200 mA at 40 V DC.
4.2.3 Digital I/O Software
void digOut (int channel, int value); |
Parameters
Return Value
See Also
int digIn (int channel); |
Parameters
Return Value
See Also
4.2.4 Sample Digital I/O Programs
- Connect the programming cable to header J4 on the TCP/IP Development Board. Apply power to the TCP/IP Development Board.
- Open the sample program
SAMPLESICOMICOMIO.Cand press F9.
Free Serial Communication Software RS232-RS422-RS485
Jul 7th
Our new comDebug program lets you communicate with almost any RS232, RS422, RS485 or Modbus serial device. Whats more, its free! Its extensive trouble-shooting capabilities make it ideal for solving comms problems, or for quickly checking that you can communicate with your instrument before starting to automatically acquire data.
Features
- No programming required
- Free technical support for life
- Easy to use
- Understands ASCII or binary data
- For serial instruments that continually send data and those that need prompting
- Quickly identify and correct communication errors
- Insert cyclic redundancy checks (CRCs)
- Send ASCII values, 16-bit 2s complement integers, unsigned integers, single bits of data, etc, to instruments
- Control the state of the PCs serial port output lines
- See the state of the serial port input lines
- Send acknowledgements
- Save settings in a file
- Full hypertext Help
- Up to 38400 baud
- For Windows 95 and later
- Optionally, with the new Windmill COMIML or free LabIML serial driver, continually send data from the instrument to the Windmill logging, charting and other data acquisition applications, or to third-party Windows software like Excel
No Programming Required
Simply select your communication settings or type your instruments commands: no need for any programming.
What sort of Devices can you Read with comDebug?
With comDebug you can control both those serial devices that continuously output messages, and those that require commands before supplying data. With a flexible approach to building command strings, and parsing the received data strings to extract data values, the majority of analytical instruments are supported. These include GPS, sonar, DMR, gas analysers, pH transmitters, data loggers, titrators, particle analysers, pressure transmitters, water baths, hygrometers, I2C devices, plcs and laboratory scales.
You have the freedom to mix and match equipment from many different manufacturers in many combinations. For example, serial devices from A&D, Anton Paar, Ashtec, Bruël & Kjær, Datel, Datataker, Ecom, Edge Tech, Electro Industries, Fisher, Furuno, Garmin, Honeywell, Horiba, Mettler Toledo, Motorola, Molyteck, Newmar, NovAtel, Nu-Metrics, Omnistar, Omron, Orion, Parallax, Paroscientific, Patton, Phytron, Quantum Logic, Quest Scientific, Sartorius, Siemens, Telegan, Telemecanique, Texas Instruments, Transcell and TTi have all been handled by Windmill. Many channels of data can be accepted from each instrument.
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Doyal J. McVicker Jr.
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R E Rogers
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J Stirling
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M O Tjebben
M O Tjebben
“Used it to simulate the data output of a Resistance Weld Control into our Web enabled PLC (programmable logic controller).”
J Franks
J Franks
Free Technical Support for Life
Our software is so easy to use we offer free technical support for life. If you have a question the first places to look are in the programs Help file or our FAQ. If you dont find the answer there then fill in our technical support form, fax us on +44 (0)161 833 2190 or call us on +44 (0)161 833 2782 (9 to 5 GMT or BST).
“comDebug is so easy to use I have not needed to read anything.”
RT, Reservoir Engineering Specialist Oil and Gas Production – Research. Using ParoScientific Quartz pressure transmitter.
RT, Reservoir Engineering Specialist Oil and Gas Production – Research. Using ParoScientific Quartz pressure transmitter.
“Great Software!”
GH, Audio Systems Engineer using Audion Precision System Two Cascade.
GH, Audio Systems Engineer using Audion Precision System Two Cascade.
“No problems, it did exactly what I wanted it to do.”
SM, Electrical Engineer performing tests on a Modbus Variable speed drive.
SM, Electrical Engineer performing tests on a Modbus Variable speed drive.
“Outstanding little tool! Best freebie Ive ever seen! No problems, it worked perfectly.”
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JF, Industrial Control Engineer.
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JF, Industrial controls.
JF, Industrial controls.
Download COMIML and comDebug Leaflet
You can download the COMIML and comDebug leaflet in pdf format.
- For best quality but large file download comiml.pdf
- For lower quality pictures but small file download comiml2.pdf.
Looking for a reliable but not too expensive reseller
Jul 7th
—– Question——–
Ive been looking for a reliable reseller host for a while and have used a few people in the past but havent found exactly what I need.
I require:
- Around 5,000mb storage
- 100gb of data transfer
- Unlimited email alias, pop3, imap accounts
- Unlimited mysql databases
- Linux based
- PHP5
- Individual control panels for each account created
I have used Media Temple before and theyre fantastic, but the only let down is with their grid server you only get one control panel unless you pay the big money for a dedicated reseller package.
Any suggestions would be greatly appreciated for a budget of around $50/month.
I require:
- Around 5,000mb storage
- 100gb of data transfer
- Unlimited email alias, pop3, imap accounts
- Unlimited mysql databases
- Linux based
- PHP5
- Individual control panels for each account created
I have used Media Temple before and theyre fantastic, but the only let down is with their grid server you only get one control panel unless you pay the big money for a dedicated reseller package.
Any suggestions would be greatly appreciated for a budget of around $50/month.
—– Answer——–
I use Hostgator for one of my resellers, they have a bit more than you are actually looking for, with their lowest 25 buck package you get 25G storage, 250G transfer, with everything else you are asking for, PLUS free WHMCS, which also comes with a free Enom reseller account. Private DNS, each customer gets Cpanel w/ Fantastico, you create hosting packages….Fully white-label and you can re-brand to your hearts content.
I have really been blown away by their service and support, everything WORKS. Im a old-time network admin, so I just dont rave about any service. But I simply havent found a better reseller solution, and really have no reason to look.
Right now you can get 20% off with the coupon code on the top of their reseller overview page.
http://www.hostgator.com/resellers.shtml
For your budget, you could actually get their 60G / 500G, and get some change back.
I have really been blown away by their service and support, everything WORKS. Im a old-time network admin, so I just dont rave about any service. But I simply havent found a better reseller solution, and really have no reason to look.
Right now you can get 20% off with the coupon code on the top of their reseller overview page.
http://www.hostgator.com/resellers.shtml
For your budget, you could actually get their 60G / 500G, and get some change back.
AVRISP mkII USB Programmer review
Jul 7th
Introduction
AVR® In-System Programmer mkII is used for field upgrades of AVR Flash microcontrollers. The AVRISP mkII combined with AVR Studio® can program all AVR® 8-bit RISC microcontrollers with ISP Interface.
Specifications
- AVR Studio compatible (AVR Studio 4.12 or later)
- Supports all AVR devices with ISP interface
- Programs both flash and EEPROM
- Supports fuses and lock bit programming
- Upgradeable to support future devices
- Support target voltages from 1.8V to 5.5V
- Adjustable programming speed (50Hz to 8MHz SCK frequency)
- USB 2.0 compliant (full speed, 12Mbps)
- Powered from USB, does not require external power supply
- Target interface protection
- Short-circuit protection
Supported AVR Microcontrollers
AT90CAN128 | AT90PWM2 | AT90PWM3 | AT90S1200 |
AT90S2313 | AT90S2343 |
AT90S2333 | AT90S4414 | AT90S4433 |
AT90S4434 | AT90S8515 | AT90S8535 |
ATmega103 | ATmega163 | ATmega1280 |
ATmega128 | ATmega8 | ATmega16 |
ATmega64 | ATmega169 |
ATmega161 | ATmega162 | ATmega163 | ATmega164 |
ATmega2560 | ATmega2561 |
ATmega32 | ATmega324 | ATmega329 | ATmega3290 |
ATmega48 |
ATmega640 | ATmega644 | ATmega649 | ATmega6490 | ATmega8515 |
ATmega8535 |
ATmega88 | ATtiny12 | ATtiny13 | ATtiny15 | ATtiny2313 |
|
ATtiny25 | ATtiny26 | ATtiny45 | ATtiny85 | ATmega1281 | AT90S2323 |
Retro 8 bit BASIC computer is a blast from the past
Jul 7th
Get in the computer time machine and travel back to the days of a simple computer thats programmed in BASIC and boots in under 1 second. Or, you can buy the Retro Computer System.
Many readers of this site will have had at least a bit of experience with the personal computers of yore, such as the Commodore 64, Apple II, Atari, or any number of other similar systems. The machines from that era were simple by todays standards but they had a certain charm and there was certainly a level of variety in the computer ecosystem that made the various models vastly different from each other (for you younguns whove only ever used Windows, there was a time in the ancient computer past where programs would not run on every machine you could buy!)
All of those early computers had several things in common. Youd turn them on and almost instantly, you were at a prompt ready to begin writing a program or doing whatever else you wanted. There was almost always a BASIC programming language that formed the base of the user interface. There was often an “expansion port” where you could hook-up either home-brew circuits or store bought goodies. It was very different from today.
The BASIC language used on the Retro will look familiar to anyone whos used any of the computers I mentioned above. It even uses line numbering! Heres a sample from the sample Eliza-esque demo:
430 COLOR 57:LOCATE 0,9:PRINT CHR$(128)
440 LOCATE 4,8:PRINT CHR$(129)
450 COLOR 22:LOCATE 0,11:PRINT CHR$(130)
460 LOCATE 4,12:PRINT CHR$(131)
470 COLOR 63:LOCATE 26,0:PRINT “USER INTERFACE”
475 LOCATE 19,13:PRINT “DOCTOR RETRO RESPONSE”
Multilabs sells a blank PCB that plugs into the expansion port and allows you to interface relays, sensors, and anything else to use with the Retro. Since there isnt an over-complicated gigabyte-sized operating system getting in the way, you can address your expansion port hardware directly without any drivers, so you can really get down to business working on your projects!
The Multilabs Retro Computer System is $100 which is relatively cheap for the functionality you get. If you dont have any PS2 keyboards, dont forget to order one (I think I dumped all my old keyboards just over a year ago – it figures!) I may put a Retro in my ever-growing to-buy list but if Multilabs wants to send an eval unit, thats cool too 
. I certainly miss the simplicity of my C64 and being able to trivially write programs and just have fun with a computer. If you have any experience with the Retro, please leave a comment below!
AVR ISP USB Programmer
Jul 7th
Introduction
This AVR ISP is a USB In System Programmer (ISP). With this ISP programmer AVR microcontrollers can be programmed without removing it from existing hardware. Both Slow and Fast programming modes are supported which allows a variety of devices to be programmed.
Specifications
- USB compatible (No legacy RS232 required)
- Programs all AVR microcontrollers
- Supports AVR DUDE IDE.
- Target can be directly powered from the programmer.
- Works under multiple platforms like Linux, Mac OS X and Windows.
- No special controllers or smd components are needed.
- Programming speed is up to 5kBytes/sec.
- SCK option to support targets with low clock speed (< 1,5MHz).
- Includes USB cable
Supported AVR Microcontrollers
|
AT90CAN128 | AT90PWM2 | AT90PWM3 | AT90S1200 | AT90S2313 | AT90S2343(*) |
AT90S2333 | AT90S4414 | AT90S4433 | AT90S4434 | AT90S8515 |
AT90S8535 |
ATmega103 | ATmega163 | ATmega1280 | ATmega128 | ATmega8 |
ATmega16 |
ATmega64 | ATmega169 | ATmega161 | ATmega162 |
ATmega163 | ATmega164 |
ATmega2560(**) | ATmega2561(**) | ATmega32 | ATmega324 |
ATmega329 | ATmega3290 |
(*) The AT90S2323 and ATtiny22 use the same algorithm.
(**) Flash addressing above 128 KB is not supported by all programming hardware.
Known to work are jtag2, stk500v2, and bit-bang programmers.
NOTE: This circuit can only be used for programming 5V target systems and for voltages level converter is needed.
Microcontroller programmer robot – Robotic microcontroller
Jul 7th
Anyone whos read this blog for any amount of time knows that I love microcontrollers and projects made with them. Well, heres a microcontroller project that creates more microcontrollers. Is this the beginning of a Terminator-esque future?
Im a sucker for cool electro-mechanical projects (if you have one youd like me to post about, use the Contact link) so when I saw this, I got excited. A guy in Hungary has created a “robot” which utilizes an old printer mechanism with a few standard radio-control servos to program microcontrollers in bulk.
The printer slide is used to provide the horizontal movement while a special mechanism moves a vacuum attachment vertically to grab the chips from the supply rail on the right. The blank microcontroller is dropped into a ZIF socket and a servo closes the latch. After the programming is complete, the arm removed the chip from the socket and transfers it to the output rail.
Ive spent a quite few years in the semiconductor manufacturing field, including several in the production areas and I can say that this guys project is actually remarkably similar to whats used by the professionals — just much slower. Ill bet that he could ramp the horizontal movement significantly but other than that, its a pretty sweet project!
Check the video out below. The first half shows the overall process and the second half shows each step in detail.
A-301 High Voltage Amplifier/ Piezo Driver and Modulator us-experts.com
Jul 7th
The A-301 piezo Driver/Piezo Amplifier is a high Voltage, high speed Bi-polar Piezo Driver / Linear Amplifier for applications where low cost amplifier is needed..
It was designed as a Linear Amplifier / Driver for PIEZO Electric Actuators (also known as “Piezo Amplifier”), stacks,piezo sheets, bimorph elements and other devices. It may be also used as a general purpose High Voltage amplifier for Medical applications (for example, as electode driver for Neurology).
The Piezo Driver / Piezo Amplifier is based on a high voltage, MOSFET amplifier which is capable of driving up to ±175V (350V ptp).
The current capacity of the A-301 is 60 mA (100 mA peak)
The current capacity of the A-301 HS is 100mA (150mA peak).
The A-301 bandwidth is 30 KHz. while the A-301 HS can go up to 200 KHz.
The slew rate of the A-301 is 30V/uSec. compared to 250V/uSec for the A-301HS.
By connecting 2 amplifiers in series, the output voltage may be doubled to 700Vptp .
The amplifier section is very stable and has a low noise output and a very low electrical noise - Compare Our Specifications!
Competitive Price!
Features:
Low cost alternative for small experiments.
Very Low Electrical Noise.
Low Distortion
High Slew rate-up to 400 Volt/microsecond.
Input protection-High Voltage, On/Off.
Output protection – Short-circuit, Power loss,Impedance.
Specifications:
A-301 Piezo Amplifier
| Amplifier section: | |
|
Maximum Input Voltage
|
± 10 V |
|---|---|
|
Maximum Output Voltage
|
± 175 V (350Vptp) |
|
Maximum Current
|
± 60 mA for A-301, +/-100mA for A-301HS |
|
Bandwidth
|
Into 1 K resistive load |
| A-301:DC – 30 kHz, A-301HS-DC-200KHz | |
|
Output Power
|
16 Watt maximum |
|
DC Gain
|
20 |
|
Coupling
|
Input & Output: Direct DC Coupling |
|
DC Offset
|
Adjustable to ± 8 Volts + On/Off Switch |
|
Input Impedance
|
10 K |
|
Slew Rate
|
A-301: 30V/ µSec, A-301HS:250V/µSec |
|
Output Noise
|
4 mV PTP max. (0.8 mV RMS max.) (input shorted, 30 KHz. BW) |
| Variable Gain Option: | 0-10X or 0 – 20X or 0-40X available. Please consult the factory regarding that option. |
| Dimensions: | H= 90mm W=134mm L=235mm |
|
AC Input
|
|
|
Line Input Voltage
|
110/120 V, 60 Hz and 220/230 V , 50 Hz (Switchable by user) |
| Line Input Current | 0.5 A peak |
Applications:
2 amplifiers can be connected in series or in parallel in order to double the Output Voltage or Output Current.
Series connection (+/- 350V into a floating load = 700V ptp).
Please note that both amplifiers must be floating (i.e. be careful not to ground them via an oscilloscope etc.)
It is also possible to double or tripple the output voltage by using a special transformer. Using a transformer is possible only at
high frequency (over 10 KHz.) and it requires more components to be added for balancing and proper termination of the load.
Parallel connection is done by adding resistors at the input and at the output. Please consult the factory for parallel connection.
Calulating the estimated current needed to drive your load:
| In order to purchase the right amplifier to drive your load, you must calulate the peak current needed. | |||
| For Capacitive load: | |||
| Ipeak(A) = 2 π F C Vpeak (for a Sine Wave) Ipeak(A) = 4 F C Vpeak (for a triangular wave) Ipeak(A) = C dV / dt (for a square wave or sharp rise time) |
|||
| F=Maximum frequency (Hz.) π=3.1415927 |
C=Capacitance in Farads Vpeak=Maximum Voltage you need to drive your Load. |
||
| For Resistive Load: | |||
| I = Vpeak/R | |||
| where R is the resistance of your load in Ohms. | |||
The current, Voltage and Frequency must be less or equal to the amplifiers specifications.
This amplifier is NOT SUITABLE for driving pure inductive loads
(i.e. speakers, solenoides, electromagnets etc.)
You must connect your load with thick wires to minimize inductance (like speaker wires). Coaxial cable is not recommended for cables over 2m (6.5 Ft.) because the capacitance of the cable (15-50 pF/Ft) will load your amplifier at high frequencies.
| Example: The active impedance of a capacitive load is given by the equation: Z=1/(2*Pi*F*C) where Pi=3.1415, C in Farads, F in Hz.The user must check that under the peak operation Voltage, at maximum frequency, the current will not exceed 200mA (0.2A). Example: Operating Voltage is +/-150V, Maximum Frequency=10KHz. Load is 10nF. Z=1/(2*3.1415*10,000*10EE-9) =1592 Ohms. 150[V]/1592[Ohm] =94[mA] ===>The amplifier will drive that load at an amplitude of 150V (300V ptp). |
Fast shipping!!!
All amplifiers are available from stock. We ship within 1 working day after your credit card was approved. Shipping is by UPS. It takes up to 3 working days to ship by UPS to any country.
We accept VISA, MaterCard, American Express. Your credit card is charged only after we ship the order.
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