It is difficult for any radio amateur to imagine his laboratory without such an important measuring instrument as an oscilloscope. And, indeed, without a special tool that allows you to analyze and measure the signals acting in the circuit, the repair of most modern electronic devices impossible.
On the other hand, the cost of these devices often exceeds the budgetary capabilities of the average consumer, which forces him to look for alternative options or make an oscilloscope with your own hands.
Options for solving the problem
Avoid buying expensive electronic products succeeds in the following cases:
- Using the built-in PC or laptop for these purposes sound card(ZK);
- Making a USB oscilloscope with your own hands;
- Refinement of a regular tablet.
Each of the options listed above, which allow you to make an oscilloscope with your own hands, is not always applicable. To fully work with self-assembled attachments and modules, the following prerequisites must be met:
- The admissibility of certain restrictions on the measured signals (by their frequency, for example);
- Experience with handling complex electronic circuits;
- Possibility of modification of the tablet.
Thus, an oscilloscope from a sound card, in particular, does not allow measuring oscillatory processes with frequencies outside its operating range (20 Hz-20 kHz). And to make a USB set-top box for a PC, you will need some experience in assembling and configuring complex electronic devices (as when connecting to a regular tablet).
Note! The option in which it is possible to make an oscilloscope from a laptop or tablet using the simplest approach comes down to the first case, which involves the use of a built-in circuit breaker.
Let's look at how each of the above methods is implemented in practice.
Use of PO
To implement this method of obtaining an image, you will need to make a small-sized attachment, consisting of only a few electronic components accessible to everyone. Its diagram can be found in the picture below.
The main purpose of such an electronic chain is to ensure the safe entry of the external signal under study to the input of the built-in sound card, which has its “own” analog-to-digital converter (ADC). The semiconductor diodes used in it guarantee that the signal amplitude is limited to a level of no more than 2 Volts, and a divider made of resistors connected in series allows voltages with large amplitude values to be supplied to the input.
A wire with a 3.5 mm plug at the mating end is soldered to the board with resistors and diodes on the output side, which is inserted into the circuit breaker socket called “Linear input”. The signal under study is supplied to the input terminals.
Important! The length of the connecting cord should be as short as possible to ensure minimal signal distortion at very low measured levels. It is recommended to use a two-core wire in a copper braid (screen) as such a connector.
Although the frequencies passed by such a limiter are in the low-frequency range, this precaution helps to improve the quality of transmission.
Program for obtaining oscillograms
In addition to the technical equipment, before starting measurements, you should prepare the appropriate software(software). This means that you need to install on your PC one of the utilities designed specifically for obtaining an oscillogram image.
Thus, in just an hour or a little more it is possible to create conditions for research and analysis of electrical signals using a stationary PC (laptop).
Finalization of the tablet
Using the built-in map
In order to adapt a regular tablet for recording oscillograms, you can use the previously described method of connecting to an audio interface. In this case, certain difficulties are possible, since the tablet does not have a discrete line input for a microphone.
This problem can be solved as follows:
- You need to take a headset from your phone, which should have a built-in microphone;
- Then you should clarify the wiring (pinout) of the input terminals on the tablet used for connection and compare it with the corresponding contacts on the headset plug;
- If they match, you can safely connect the signal source instead of a microphone, using the previously discussed attachment on diodes and resistors;
- Finally, all you have to do is install it on your tablet. special program, capable of analyzing the signal at the microphone input and displaying its graph on the screen.
Advantages this method Connecting to a computer is easy to implement and low cost. Its disadvantages include the small range of measured frequencies, as well as the lack of a 100% guarantee of safety for the tablet.
These shortcomings can be overcome through the use of special electronic set-top boxes connected via a Bluetooth module or via a Wi-Fi channel.
Homemade attachment for Bluetooth module
Connection via Bluetooth is carried out using a separate gadget, which is a set-top box with an ADC microcontroller built into it. Due to the use independent channel processing information, it is possible to expand the bandwidth of transmitted frequencies to 1 MHz; in this case, the input signal value can reach 10 Volts.
Additional Information. The range of action of such a self-made attachment can reach 10 meters.
However, not everyone is able to assemble such a converter device at home, which significantly limits the range of users. For everyone not ready for self-production consoles, it is possible to purchase a finished product, which has been available for free sale since 2010.
The above characteristics may suit a home mechanic who repairs not very complex low-frequency equipment. For more labor-intensive repair operations, professional converters with a bandwidth of up to 100 MHz may be required. These capabilities can be provided by a Wi-Fi channel, since the speed of the data exchange protocol in this case is incomparably higher than in Bluetooth.
Set-top oscilloscopes with data transmission via Wi-Fi
The option for transmitting digital data using this protocol significantly expands throughput measuring device. Working on this principle and freely sold set-top boxes are not inferior in their characteristics to some examples of classic oscilloscopes. However, their cost is also far from being considered acceptable for users with average incomes.
In conclusion, we note that taking into account the above limitations, the Wi-Fi connection option is also suitable only for a limited number of users. For those who decide to abandon this method, we advise you to try to assemble a digital oscilloscope that provides the same characteristics, but by connecting to a USB input.
This option is also very difficult to implement, so for those who are not completely confident in their abilities, it would be wiser to purchase a ready-made USB set-top box that is commercially available.
Video
Oscilloscopes have changed as much as televisions over the past 20 years. From large, heavy boxes to compact, pocket-sized devices with color LCD displays. True, the cost has always been and remains difficult to achieve for a beginning radio amateur. But the situation will soon change, because now the main part of the functions will be taken over by a regular smartphone. IkaScope is a new wireless oscilloscope probe that is capable of transmitting measurements directly to your mobile phone or laptop. IkaScope connects via a high-speed WiFi connection and works with iOS, Android and Windows devices, including OSX.
The IkaScope wireless oscilloscope probe looks like a small marker. It uses a WiFi connection to transmit signals that will be displayed on any connected screen (laptop, smartphone, tablet or desktop computer). It comes with a rechargeable battery that can be charged via any USB port. IkaScope provides 4 kV galvanic isolation from the mains supply.
Specifications
- The division value is 10 mV/div. → 10 V/div
- Maximum input voltage 80 Vpp
- Bandwidth 25 MHz
- Period 100 ns/div → 10 s/div
- Input impedance 1MΩ
- Trigger start
- Sampling rate 200 MSPS
- Resolution 8-bits
- Buffering 4K pts (4 x 1K Pts)
Thus, we can affirm the advent of a new era of measuring instruments - which are small, self-powered wireless sensors, within which all processing of the measured signal is carried out, with further data transmission to any smartphone or tablet. Moreover, monitoring voltage, capacitance, current and other simple parameters will soon also move from digital multimeters to remote measuring probes that work with phones.
On the website http://www.semifluid.com I found a very simple solution for creating a digital computer oscilloscope. The device is based on an eight-bit PIC12F675 processor.
The processor operates at a frequency of 20 MHz. The microcontroller continuously measures the input voltage, converts it, and sends a digital value to the computer's serial port. The serial port baud rate is 115 kBit and, as shown in the following figure, data is scanned and sent at a rate of about 7.5 kHz (134 µs).
Device diagram
The basis of the circuit is the PIC12F675 microcontroller (U2 chip) which operates at a clock frequency of 20 MHz of the Y1 crystal. J1 is a standard power connector for connecting 9-12 V power, which is then stabilized at U1 to 5 V to power the processor.
After U2, a simple TTL level converter with an RS232 serial port is added to the circuit personal computer. It is built on the basis of transistor BC337 (Q1) and resistors R1 and R3. Input 5 of the microcontroller leads to switch S1. In its main position (1-2), the device switches to DC oscilloscope mode, which is capable of displaying a 0-5V input signal. In the second position - into AC oscilloscope mode. In this position, the maximum voltage is from -2.5 to +2.5 V. I used a 22000nF ceramic capacitor C6 to observe low frequencies without much distortion.
If necessary, you can add an additional input attenuator (splitter), or op-amp.
Software
In the original website mentioned above, also available simple program controls for Windows. The program is written in Visual Basic.
The program starts immediately and waits for data to appear on the COM1 serial port. On the left, four sliders used to measure the period and voltage of the signal. Then there are on/off synchronization, fields for scaling or changing sample size values.
Installation
I did not make a printed circuit board, but mounted everything in a small plastic box using a surface-mounted system. The case must have holes for the RS232 connector of the switch, input jack, power jack.
Firmware for the processor is at the end of the article. The configuration bits (fuse) must be set as follows during programming:
Photo of my finished prototype
Below you can download the source, firmware and software for windows
List of radioelements
| Designation | Type | Denomination | Quantity | Note | Shop | My notepad |
|---|---|---|---|---|---|---|
| U1 | Linear regulator | 1 | Search in Chip and Dip | To notepad | ||
| U2 | MK PIC 8-bit | 1 | 675-I/P | Search in Chip and Dip | To notepad | |
| Q1 | Bipolar transistor | 1 | Search in Chip and Dip | To notepad | ||
| C1, C2, C5 | Capacitor | 0.1 µF | 3 | Search in Chip and Dip | To notepad | |
| C3, C4 | Capacitor | 22 pF | 2 | Search in Chip and Dip | To notepad | |
| C6 | Capacitor | 22 µF | 1 | Search in Chip and Dip | To notepad | |
| R1, R3 | Resistor | 2 |
Nowadays, there is quite a lot of use of various measuring devices based on interaction with a personal computer. A significant advantage of their use is the ability to store the obtained values in a sufficiently large volume in the device’s memory, with their subsequent analysis.
Digital USB oscilloscope from computer, the description of which we provide in this article, is one of the options for such measuring instruments radio amateur. It can be used as an oscilloscope and a device for recording electrical signals in RAM and on HDD computer.
The circuit is not complicated and contains a minimum of components, resulting in a very compact device.
Main characteristics of USB oscilloscope:
- ADC: 12 bits.
- Time base (oscilloscope): 3…10 ms/division.
- Time scale (recorder): 1…50 sec/sample.
- Sensitivity (without divider): 0.3 Volts/division.
- Synchronization: external, internal.
- Data recording (format): ASCII, text.
- Maximum input resistance: 1 MΩ in parallel with a 30 pF capacitance.
Description of the operation of an oscilloscope from a computer
To exchange data between a USB oscilloscope and a personal computer, the Universal Serial Bus (USB) interface is used. This interface operates on the basis of the FT232BM (DD2) microcircuit from Future Technology Devices. It is an interface converter. The FT232BM chip can operate both in direct BitBang bit control mode (when using the D2XX driver) and in virtual COM port mode (when using the VCP driver).
The AD7495 (DD3) integrated circuit from Analog Devices is used as an ADC. It is nothing more than a 12-bit A/D converter with an internal voltage reference and a serial interface.
The AD7495 chip also contains a frequency synthesizer that determines the speed at which information will be exchanged between the FT232BM and the AD7495. To create the necessary data exchange protocol, USB program The oscilloscope populates the USB output buffer with the individual bit values for the SCLK and CS signals as shown in the following figure:
The measurement of one cycle is determined by a series of nine hundred and sixty successive transformations. The FT232BM chip, with a frequency determined by the built-in frequency synthesizer, sends electrical signals SCLK and CS, in parallel with the transmission of conversion data on the SDATA line. The 1st full conversion period of the FT232BM ADC, which sets the sampling frequency, corresponds to the duration of the period of sending 34 bytes of data issued by the DD2 chip (16 data bits + CS line pulse). Since the speed of data transfer of the FT232BM is determined by the frequency of the internal frequency synthesizer, to modify the sweep values you only need to change the values of the frequency synthesizer of the FT232BM chip.
The data received by the personal computer, after some processing (change of scale, zero adjustment) is displayed on the monitor screen in graphical form.
The signal under study is supplied to connector XS2. The OP747 operational amplifier is designed to match the input signals to the rest of the oscilloscope's USB circuitry.
On modules DA1.2 and DA1.3, a circuit is built to shift the bipolar input signal to the positive voltage zone. Since the internal reference voltage of the DD3 chip has a voltage of 2.5 volts, without using dividers, the input voltage coverage is -1.25..+1.25 V.
To be able to study signals that have negative polarity, with virtually unipolar power supply from the USB connector (a), a voltage converter DD1 is used, which generates a voltage of negative polarity to power the op-amp OP747. To protect the analog part of the oscilloscope from interference, components R5, L1, L2, C3, C7-C11 are used.
The uScpoe program is designed to display information on a computer monitor screen. Using this program, it becomes possible to visually evaluate the magnitude of the signal under study, as well as its shape in the form of an oscillogram.
The ms/div buttons are used to control the sweep of the oscilloscope. In the program, you can save the oscillogram and data to a file using the corresponding menu items. To virtually turn the oscilloscope on and off, use the Power ON/OF buttons. When you disconnect the oscilloscope circuit from the computer, the uScpoe program is automatically switched to OFF mode.
In electrical signal recording mode (recorder), the program creates text file, whose name can be set in the following path: File->Choice data file. the data.txt file is initially generated. The files can then be imported into other applications (Excel, MathCAD) for further processing.
(3.0 Mb, downloaded: 3,610)
An oscilloscope is a very important instrument that is used in radio engineering laboratories involved in the manufacture and testing of many devices. But they can also be used in ordinary radio workshops. The main task of devices of this type is to detect and correct electronic circuits, debug their operation, and most importantly, to prevent problems in the manufacture of new circuits.
A significant drawback of oscilloscopes is their fairly high price. Therefore, not everyone can buy them. That's why the question arises, ? Although there are many known options for such manufacturing, each method involves one main element - a PC sound card. An adapter is attached to it, thanks to which the levels of the measured signals are coordinated.
Software
This device works thanks to specific program. It transmits signals to the screen that are visualized. In this way, the measured pulses are converted. The choice of utilities is quite large, but not all of them can work consistently well.
The proven Osci program has gained the most popularity. Thanks to it, the oscilloscope works in normal mode. The program has an interface; a grid is installed on the screen, thanks to which you can measure the signal in length and amplitude. This mesh is special because it provides additional features. By choosing this program, there are a number of positive aspects that other programs cannot guarantee.
Technical data
To build an oscilloscope from a computer, you need to assemble a so-called voltage divider or attenuator. This device allows you to cover a wide range of measured voltages and protect the input port of the sound card from damage. Damage of this level occurs mainly due to high voltage.
Almost all audio cards have an input voltage of no more than 2 volts. An oscilloscope made from a computer is limited in the capabilities of the sound card. If we consider budget cards, then for them this figure remains at the level of 0.1 Hz - 20 kHz.
The voltage at its lower point is 1 mV. Such a low figure is explained by the limitation of background and noise levels. Upper voltage parameters – up to 500 volts. It is limited by the adapter parameters.
Advantages and disadvantages of oscilloscopes
No radio amateur can do without an oscilloscope. Although this device is sold at a fairly high price. But at the same time, it has both advantages and a number of disadvantages.
The main advantage of an oscilloscope created with your own hands from a computer is its low price. That is, you will have to spend very little money on its re-equipment. But there are several disadvantages:
1. High sensitivity. The device reacts to interference even low level. This leads to large errors.
2. Sound signal amplitude up to 2V. The sound card input is not able to withstand more. Therefore, the sound card can fail quite quickly. However, this can be avoided.
3. Failure to continuously measure voltage. This, in fact, is not a significant drawback.
Creating an Oscilloscope
Since some oscilloscopes do not allow a signal higher than 2V, and for some it does not exceed 1V, you need to try to eliminate this problem, since such an amplitude is clearly not enough. The solution to the problem lies in increasing the limits that the adapter can handle. A modern program that ensures the operation of an oscilloscope allows one to achieve such measurement limits - 12.5 and 250 Volts.
If a signal whose amplitude is 250 Volts is not needed, then you can make an adapter with two channels. To do this, a protection is installed that controls the operation of the device, that is, it does not allow erroneous switching on if the voltage is quite high.
To reduce the influence of external noise on the oscilloscope from the computer, it is necessary to place the board in a housing made of metal. Afterwards, a common wire is connected to this housing.
The process of setting up the sound card is accompanied by turning off the microphone gain. To do this, the volume on it is set to average or below average. Once all the work is done, you can start measuring the secondary processing pulses of the transformer. If everything is done correctly, then it will be able to display oscillograms of even the most low frequencies. Thanks to installed program it will be possible to easily determine the signal frequency level.
It's pretty easy to do this modern device from the computer. The oscilloscope will produce waveforms that will help in work and experiments carried out in radio engineering and home laboratories.
Below is a project of a USB oscilloscope that you can assemble with your own hands. The capabilities of the USB oscilloscope are minimal, but for many amateur radio tasks it will do just fine. Also, the circuit of this USB oscilloscope can be used as a basis for building more serious circuits. The circuit is based on an Atmel Tiny45 microcontroller.
The oscilloscope has two analog inputs and is powered by a USB interface. One input is activated via a potentiometer, which allows you to reduce the input signal level.
The software for the tiny45 microcontroller is written in C and compiled using V-USB developed by Obdev, which implements HID devices on the microcontroller side.
The circuit does not use external quartz, but uses the USB frequency of 16.5 MHz in software. Naturally, you should not expect 1Gs/s sampling from this scheme.
The oscilloscope operates via USB via HID mode, which does not require the installation of any special drivers. Windows software is written using .NET C#. Using my program source code as a basis, you can expand the software as you need.
The circuit diagram of a USB oscilloscope is very simple!
List of used radioelements:
1 LED (any)
1 LED resistor, 220 to 470 ohms
2 x 68 Ohm resistors for USB D+ & D-lines
1 x 1.5K resistor for USB device detection
2 3.6V Zener diodes for USB level equalization
2 capacitors 100nF and 47uF
2 filter capacitors on analog inputs (from 10nF to 470nF), it is possible without them
1 or 2 potentiometers on analog inputs, to reduce the input voltage level (if necessary)
1 USB port
1 Atmel Tiny45-20 microcontroller.
List of radioelements
| Designation | Type | Denomination | Quantity | Note | Shop | My notepad |
|---|---|---|---|---|---|---|
| R1, R5 | Resistor | 2 | Search in Chip and Dip | To notepad | ||
| R2 | Resistor | 1 | Search in Chip and Dip | To notepad | ||
| R3 | Resistor | 1 |
An oscilloscope is a tool that almost every radio amateur has. But for beginners it is too expensive.
The problem of high cost is easily solved: there are many options for making an oscilloscope.
The computer is perfect for such a modification, and its functionality and appearance will not be harmed in any way.
Device and purpose
The circuit diagram of an oscilloscope is difficult for a novice radio amateur to understand, so it should not be considered as a whole, but first broken down into separate blocks:
Each block represents a separate microcircuit or board.
The signal from the device under test is supplied through the Y input to the input divider, which sets the sensitivity of the measuring circuit. After passing preamp and the delay line it goes to the final amplifier, which controls the vertical deflection of the indicator beam. The higher the signal level, the more the beam is deflected. This is how the vertical deflection channel is designed.
The second channel is horizontal deflection, needed to synchronize the beam with the signal. It allows you to keep the beam in the place specified by the settings.
Without synchronization, the beam will float off the screen.
Synchronization happens three types: from an external source, from the network and from the signal being studied. If the signal has a constant frequency, then it is better to use synchronization from it. The external source is usually a laboratory signal generator. Instead, a smartphone with a special application installed on it is suitable for these purposes, which modulates the pulse signal and outputs it to the headphone jack.
Oscilloscopes are used in the repair, design and configuration of various electronic devices. This includes car system diagnostics, troubleshooting V household appliances and much more.
The oscilloscope measures:
- Signal level.
- Its shape.
- Pulse rise rate.
- Amplitude.
It also allows you to sweep a signal down to thousandths of a second and view it in great detail.
Most oscilloscopes have a built-in frequency counter.
Oscilloscope connected via USB
There are many manufacturing options homemade USB oscilloscopes, but not all of them are accessible to beginners. The most simple option It will be assembled from ready-made components. They are sold in radio stores. A cheaper option would be to buy these radio components in Chinese online stores, but you need to remember that components purchased in China may arrive in a faulty condition, and money for them is not always returned. After assembly, you should get a small set-top box that connects to a PC.
This version of the oscilloscope has the highest accuracy. If the problem arises of which oscilloscope to choose for repairing laptops and other complex equipment, it is better to opt for it.
For production you will need:
- Board with separated tracks.
- Processor CY7C68013A.
- AD9288−40BRSZ analog-to-digital converter chip.
- Capacitors, resistors, chokes and transistors. The values of these elements are indicated on the circuit diagram.
- Soldering gun for sealing SMD components.
- Wire in varnish insulation with a cross-section of 0.1 mm².
- Toroidal core for winding a transformer.
- A piece of fiberglass.
- Soldering iron with a grounded tip.
- Solder.
- Flux.
- Solder paste.
- Memory chip EEPROM flash 24LC64.
- Frame.
- USB connector.
- Socket for connecting probes.
- Relay TX-4.5 or other, with a control voltage of no more than 3.3 V.
- 2 AD8065 operational amplifiers.
- DC-DC converter.
You need to collect according to this scheme:
Usually, radio amateurs use the etching method to make printed circuit boards. But to make it double-sided this way printed circuit board With complex wiring you won’t be able to do it yourself, so you need to order it in advance from a factory that produces such boards.
To do this, you need to send a drawing of the board to the factory, according to which it will be manufactured. The same factory makes boards of different quality. It depends on the options selected when placing your order.
In order to get a good payment in the end, you need to indicate in the order the following conditions:
- The thickness of fiberglass is at least 1.5 mm.
- The thickness of copper foil is at least 1 OZ.
- Through metallization of holes.
- Tinning of contact pads with lead-containing solder.
After receiving the finished board and purchasing all the radio components, you can begin assembling the oscilloscope.
The first to assemble is a DC-DC converter that produces voltages of +5 and -5 volts.
It needs to be assembled on a separate board and connected to the main one. using shielded cable.
Solder the microcircuits to the main board carefully, without overheating them. The temperature of the soldering iron should not be higher than three hundred degrees, otherwise the soldered parts will fail.
After installing all components, assemble the device into a suitable-sized housing and connect it to computer USB cable. Close jumper JP1.
You need to install and launch the Cypress Suite program on your PC, go to the EZ Console tab and click on LG EEPROM. In the window that appears, select the firmware file and press Enter. Wait for the message Done to appear, indicating the successful completion of the process. If the message Error appears instead, it means that an error occurred at some stage. You need to restart the flasher and try again.
After flashing the firmware, your self-made digital oscilloscope will be completely ready for use.
Self-powered option
At home, radio amateurs usually use stationary devices. But sometimes a situation arises when you need to repair something located far from home. In this case, you will need a portable, self-powered oscilloscope.
Before starting assembly, prepare the following components:
- Unnecessary bluetooth headphones or audio module.
- Android tablet or smartphone.
- Lithium-ion battery size 18650.
- Holder for him.
- Charge controller.
- Jack 2.1 x 5.5 mm.
- Connector for connecting test leads.
- The probes themselves.
- Switch.
- Plastic shoe sponge box.
- Shielded wire with a cross section of 0.1 mm².
- Tact button.
- Hot melt adhesive.
Needs to be disassembled wireless headset and remove the control board from it. Unsolder the microphone, power button and battery from it. Set the board aside.
Instead of Bluetooth headphones, you can use a Bluetooth audio module.
Use a knife to scrape off the remaining sponge from the box and clean it well using detergents. Wait until it dries and cut out holes for the button, switch and connectors.
Solder the wires to the sockets, holder, button and switch. Place them in place and secure with hot glue.
The wires must be connected as follows shown in the diagram:
Explanation of symbols:
- Holder.
- Switch.
- Contacts “BAT + and “BAT -”.
- Charge controller.
- Contacts “IN + and “IN -”.
- Jack 2.1 x 5.5 mm connector.
- Contacts “OUT+ and “OUT -”.
- Battery contacts.
- Control board.
- Power button contacts.
- Tact button.
- Probe socket.
- Microphone contacts.
Then download the virtual oscilloscope application from the play market and install it on your smartphone. Turn on the Bluetooth module and synchronize it with your smartphone. Connect the probes to the oscilloscope and open its software on your phone.
When you touch the signal source with the probes, a curve showing the signal level will appear on the screen of your Android device. If it doesn't appear, it means a mistake was made somewhere.
You should check the correct connection and serviceability of the internal components. If everything is ok, you need to try to start the oscilloscope again.
Installation in the monitor case
This version of a homemade oscilloscope is easily installed in the housing of a desktop LCD monitor. This solution allows you to save some space on your desktop.
For assembly you will need:
- Computer LCD monitor.
- DC-DC inverter.
- Motherboard from a phone or tablet with HDMI output.
- USB connector.
- A piece of HDMI cable.
- Wire with a cross section of 0.1 mm².
- Tact button.
- 1 kOhm resistor.
- Double sided tape.
Every radio amateur can build an oscilloscope into a monitor with his own hands. First you need to remove it from the monitor back cover and find a place to install motherboard. Once you have decided on the location, next to it you need to cut holes in the case for the button and USB connector.
The second end of the cable must be soldered to the board from the tablet. Before soldering each wire, test it with a multimeter. This will help you avoid confusing the order in which they are connected.
Next step You need to remove the power button and micro USB connector from the tablet board. Solder wires to the clock button and USB socket and secure them in the cut holes.
Then connect all the wires as shown in the figure and solder them:
Place a jumper between the GND and ID contacts in the micro USB connector. This is necessary to switch the USB port to OTG mode.
You need to glue the inverter and the motherboard from the tablet with double-sided tape, and then snap the monitor cover.
Connect to USB port mouse and press the power button. While the device is booting up, turn on the Bluetooth transmitter. Then you need synchronize it with the receiver. You can open the oscilloscope application and verify the functionality of the assembled device.
Instead of a monitor, an old LCD TV that does not have a Smart TV is also perfect. The tablet's hardware surpasses many Smart TV systems in its capabilities. You should not limit its use to just an oscilloscope.
Manufacturing from an audio card
An oscilloscope assembled from an external audio adapter will cost only 1.5-2 dollars and will take a minimum of time to manufacture. In size it will be no larger than a regular flash drive, and in terms of functionality it will not be inferior to its larger brother.
Required parts:
- USB audio adapter.
- 120 kOhm resistor.
- Mini Jack 3.5 mm plug.
- Test leads.
You need to disassemble the audio adapter; to do this, you need to pry the housing halves open and separate them.
Remove capacitor C6 and solder a resistor in its place. Then install the board back into the case and reassemble it.
You should cut off the standard plug from the probes and solder a mini-jack in its place. Connect the probes to audio input audio adapter.
Then you need to download the corresponding archive and unpack it. Insert the card into the USB connector.
The simplest thing left is to go to Device Manager and in the “Audio, game and video devices” tab, find the connected USB audio adapter. Click on it right click mouse and select “Update Driver”.
Then move the files miniscope.exe, miniscope.ini and miniscope.log from the archive to a separate folder. Run "miniscope.exe".
Before use, the program must be configured. Required settings shown in the screenshots:
If you touch the signal source with the probes, a curve should appear in the oscilloscope window:
So to turn audio adapter for oscilloscope, you need to put in a minimum of effort. But it is worth remembering that the error of such an oscilloscope is 1-3%, which is clearly not enough to work with complex electronics. It is perfect for a beginner radio amateur, but craftsmen and engineers should take a closer look at other, more accurate oscilloscopes.
She developed her first virtual device, she created new market and has helped many developers evaluate the possibilities of using the personal computer as a test and measurement platform. The availability of a PC for every developer became a driving force in the market at that time, making it possible to turn a PC or laptop into the basis of an instrumentation platform with inexpensive hardware and software data collection. Now, in addition to National Instruments, which has succeeded in this area, many other small companies have appeared on the market offering USB devices data collection, which are called USB/PC oscilloscopes.
But today, most electronics developers have smartphones, and it would be common for them to use their smartphone, if not as a test platform, then at least to display the data obtained. This opens up a new direction in the development of virtual devices.
The data acquisition hardware, combined with a computing platform, can be made very compact, smaller than a credit card.
This concept has given rise to two interesting virtual instruments available on the market today. We are talking about SmartScope from LabNation and Red Pitaya. Both projects are open source ( open source), and are developed based on Xilinx FPGAs. Displayed on mobile phone Signal frequency and amplitude can be changed using a conventional touch interface, eliminating the need for rotary knobs.
LabNation SmartScope
SmartScope costs about $200. Depending on the additional external peripherals included in the kit, the price may vary slightly, either down or up.
SmartScope can receive power via a connected smartphone USB cable or via an external USB power supply. SmartScope can perform the functions of not only an oscilloscope, but also a logic analyzer and signal generator.
SmartScope supports various OS, including Linux, iOS, Android and Windows. However, connecting to any of them may cause difficulties. SmartScope can be recognized if you install a jailbreak patch on your iOS device (iPhone and iPad). And in case of Android you should check if yours supports phone usb OTG. But with the majority latest phones on Android based there shouldn't be such problems. Still, we strongly recommend that you check the details on the website.
Red Pitaya
Red Pitaya is more expensive, but it won't put you through the inconvenience that you might encounter when starting out with SmartScope. Although the Red Pitaya is similar to the SmartScope in most respects, it offers smartphone apps that can be downloaded from the cloud for specific applications. You can also develop your own native applications. Red Pitaya is based on Xilinx Zynq FPGA, while SmartScope uses Xilinx's Spartan. The use of modern FPGAs makes reconfiguration of both devices as simple as possible. FPGA programmers can apply their skills to improve the performance of these devices.
Red Pitaya operates as a web server that can be accessed from any internet-connected computer or smartphone by entering the IP address in a web browser. Red Pitaya can be connected to the network either using network cable, or via Wi-Fi. A microUSB port is provided to power the device, as well as to connect it to another console. The system comes pre-installed with Linux OS, power supply, BNC connectors and probes. With its own DHCP configuration, setting up Red Pitaya is a breeze. There is also the possibility manual settings. The SD card supplied with the device contains all the necessary software, but downloading from your own card will not cause any difficulties.
The list of currently available applications includes an oscilloscope, signal generator, spectrum analyzer, LCR meter and more. They are as easy to download as any smartphone app; To do this you need to visit the website.
It is also possible to import data from MATLAB, or, conversely, export it to MATLAB.
Radio amateurs or students who want to create a laboratory on their own desk and do not need a bandwidth above 50 MHz should not purchase expensive oscilloscopes.
The Red Pitaya is $200 more expensive than the Smartscope, which is approximately $370-$470.
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