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11

That'll be because you're creating an audio signal - an audio signal is AC coupled, and will always want to drift towards ground since ground is what it is centred around. An android phone's headphone socket cannot create reliable digital waveforms since it's an analog output. You should instead choose something that is suited to what you want, instead of ...


11

None of the smartphones today have dedicated GPS chips in them, they only have a GPS capability that stems from byproduct features of the modem chips. That's not true. GPS functionality in phones is done either with a dedicated chip, or with a dedicated GPS receiver within a System-On-Chip (which is effectively the same as having a dedicated chip). ...


10

The signal from the headphone jack is most likely AC-coupled. The easy way to fix this is to add a diode from each signal line to ground: anode of both diodes to ground, cathode of each diode to your signal line. The diodes act as a clamp and allow the signal to NOT go lower than about -0.6V. The remainder of the signal amplitude is above ground (...


7

Option A is feasible, but non-trivial. Option B: Without using Bluetooth, there isn't any ready wireless radio serial output that any Android phones have, to my knowledge. There is an option C, if the requirement is relatively close range, and purely for hobby experimentation: Programmatically generate a ~ 19-20 KHz audio output from the Android's ...


7

There is no such thing like "datasheet for phone". Phone is consumer electronics. Consumer doesn't have to know all these things. All you can/should get from manufacturer is manual (that usually says: "use original battery charger"). I would not recommend trying to power phone from 12V even if you are sure that there is BQ24190 chip, because you don't know ...


6

The Google Play page for the app you linked has a section for microphone support which includes a link to an instructable for a circuit: ***** Microphone SUPPORT ****** The second option is the microphone input to the android device. This can be used to attach a scope lead to the jack socket. More information can be found at the following website. ...


5

The feasibility of transferring live video over Bluetooth from an Android mega is low but not zero, being constrained by the following: Bluetooth practical throughput limitations: Bluetooth 1.2 = ~ 700 Kbit / sec Bluetooth 2.0+EDR = ~ 2.1 MBit / sec Bluetooth 3.0+HS, 4.0: These use a separate wireless path (e.g. 802.11, like WiFi) for the high speed data, ...


4

This easiest way to do this is to buy a bluetooth module which has serial port profile built-in to its firmware (Roving networks/ panasonic etc have such modules). Assuming your "device" has a microcontroller, the microcontroller could communicate to the BT module via some communication interface (say UART) to transmit and receive data. At the mobile phone ...


4

FFC/FPC, like Oli says. There are common connectors, or ZIF "Zero Insertion Force" connector. In the latter you first insert the FFC, then click the top part in the bottom part to fix it. ZIF connectors may be handy, since otherwise the FFC may get crooked when inserting; in my experience the insertion force can be rather high. On one occasion we had our ...


4

There isn't really a standard, it depends on exactly what headphone amplifier the phone uses. The closest thing is the -10dBV (.9VPP) consumer line level output, but I doubt most phones have the actual output level calibrated to that standard. It's more than likely that they tested it by plugging the phone into a couple of AV receivers and found that it got "...


4

A digital pin, when used as input, offers very little input resistance. Note that this holds for DC current. Since you want to scale \$12V\$ to be \$5V\$: $$5V=12V\frac{R_1}{R_1+R_2}$$ that leads to \$R_1=0.417(R_1+R_2)\$. There still is a degree of freedom, that is the total divider resistance. The factors that can help you to choose it are: Your \$12V\$ ...


4

From FT232R datasheet: TEST: Puts the device into IC test mode. Must be tied to GND for normal operation, otherwise the device will appear to fail. In your schematic the TEST-pin is floating


4

To solve this problem you can instead modify the encoding so the sum of 1 and 0 bits actually sent over the wire converges to equal and the number of consecutive 1s and 0s is minimal. This means sending some extra bits over the wire but it will remove the DC component that the audio hardware can't handle. This means using a constant weight encoding or Paired ...


3

There's pretty much no chance you'll get all this for $4, it is not a realistic budget for this. But that's not to say it's not possible. You do need a microcontroller with USB functionality (or have it bit-banged, but USB ones are cheap enough) to talk to the Android phone. Then the Android phone could use its USB API in the SDK to talk to it and issue a ...


3

Controlling The ADC As a general approach, I would have the controlling app tell the PIC32 what the sample rate to use. So, for example, you select a time interval of 0.1 seconds, and the PIC32 now samples 10 times a second. The PIC32 could stream samples instantly or bucket them in smaller time increments, like every 3 seconds, etc. Having the ...


3

Four cells will put you over the nominal voltage of a single Li-Ion cell and it might be OK considering they will use a switch-down converter. However that is not guaranteed, it may damage the phone, it may have over-voltage protection that will prevent it starting up or worst case may have some form of clamps that will damage your batteries and/or cause a ...


3

(Expanding on Kurt E Clothier's comment ...) As often, the answer should be "it depends", in this case on the nature of the signal that's being transmitted via the coax cable. If the original signal is an analog type signal this type of transmission would involve several steps: Conversion of the analog signal into digital byte stream using an analog-to-...


3

A few problems that I can see are: The JY-MCU appears to be a 3.3V device and you have it connected to VIN which is 5V. Try connecting to the 3V3 line although be aware this will be available only when running from USB power because it's supplied by the FTDI USB chip. Before doing that though I've found references to it not having 5V tolerant serial lines ...


3

You would need some hardware added to the Uno which supports USB host mode, yes. This could be in the form of a USB host shield or some other USB host module (typically with its own on-board microcontroller) Yes, definitely. Typically a board which incorporates USB host mode, would also be supported by its tried and tested libraries for implementing the host ...


3

If your Android device supports USB OTG(On the go) you might be able to use the Arduino as a standard USB serial device connected to the android. My phone can do this I just needed a cheap cable to convert the micro USB to a USB A port. I used the ArduinoCommander App to test out the connection.


3

It is not unusual to have a USB device draw its power from a source other than the USB connection; such a configuration is called "self-powered" and the device's datasheet will give the exact schematic, components, and sometimes even PCB layout to make such a thing possible. It is resistances placed on the D+ and D- lines that announce presence rather than ...


3

You indicated Bluetooth doesn't satisfy your requirements, and I agree. But that's classic Bluetooth. Are you familiar with BLE (Bluetooth Low Energy, part of the Bluetooth 4.0 spec)? The maximum range is anywhere from 50m to 450m, depending on the module used. (That last figure is not a typo, here is the BLE121LR -- LR for long-range. And it still runs ...


3

I haven't trawled through all your code, but one immediate mistake I see is this: uint8_t msg[3]={0x0}; ... digitalWrite(LED4, msg[3]==0x1 ? HIGH : LOW); You allocate an array of 3 bytes (slices 0..2) and then reference slice 3, which is the 4th byte of a 3-byte array.


3

The white wire is (99.5 % certainly) a temperature measuring thermistor connection that helps your system not destroy the battery and in the process create smouldering ruin. If your battery gets too hot the system will stop charging - if it 'knows' the battery is too hot. If not ... . Batteries without this 3rd connection are relatively rare and it may ...


3

No. USB uses complex digital signaling on those data lines, that requires some digital processing power to work at all. Using an USB enabled microcontroller to translate the output of the sensor would be one of the simplest solutions, but it needs its own program.


3

Try to power your tablet through 5V USB port without the battery installed. The tablet has battery management, replacing battery with voltage from regulator may flag the error causing shutdown.


2

You will need the arduino ADK shield http://www.emartee.com/product/42089/Arduino%20ADK%20Shield%20For%20Android This works with all kinds of arduinoes :)


2

If you are asking about the ribbon connector, they are known as FFC/FPC (flexible flat cable, flexible printed circuit) cables. For connectors places like Digikey, Mouser, RS, Farnell sell them - here is the FFC/FPC page at Farnell.


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