AnalogInput¶

class wpilib.AnalogInput(channel: int)¶

Bases: Sendable

Analog input class.

Connected to each analog channel is an averaging and oversampling engine. This engine accumulates the specified ( by SetAverageBits() and SetOversampleBits() ) number of samples before returning a new value. This is not a sliding window average. The only difference between the oversampled samples and the averaged samples is that the oversampled samples are simply accumulated effectively increasing the resolution, while the averaged samples are divided by the number of samples to retain the resolution, but get more stable values.

Construct an analog input.

Parameters:: channel – The channel number on the roboRIO to represent. 0-3 are on-board 4-7 are on the MXP port.

getAccumulatorCount() → int¶

Read the number of accumulated values.

Read the count of the accumulated values since the accumulator was last Reset().

Returns:: The number of times samples from the channel were accumulated.

getAccumulatorOutput() → Tuple[int, int]¶

Read the accumulated value and the number of accumulated values atomically.

This function reads the value and count from the FPGA atomically. This can be used for averaging.

Parameters:

value – Reference to the 64-bit accumulated output.
count – Reference to the number of accumulation cycles.

getAccumulatorValue() → int¶

Read the accumulated value.

Read the value that has been accumulating. The accumulator is attached after the oversample and average engine.

Returns:: The 64-bit value accumulated since the last Reset().

getAverageBits() → int¶

Get the number of averaging bits previously configured.

This gets the number of averaging bits from the FPGA. The actual number of averaged samples is 2^bits. The averaging is done automatically in the FPGA.

Returns:: Number of bits of averaging previously configured.

getAverageValue() → int¶

Get a sample from the output of the oversample and average engine for this channel.

The sample is 12-bit + the bits configured in SetOversampleBits(). The value configured in SetAverageBits() will cause this value to be averaged 2**bits number of samples.

This is not a sliding window. The sample will not change until 2**(OversampleBits + AverageBits) samples have been acquired from the module on this channel.

Use GetAverageVoltage() to get the analog value in calibrated units.

Returns:: A sample from the oversample and average engine for this channel.

getAverageVoltage() → float¶

Get a scaled sample from the output of the oversample and average engine for this channel.

The value is scaled to units of Volts using the calibrated scaling data from GetLSBWeight() and GetOffset().

Using oversampling will cause this value to be higher resolution, but it will update more slowly.

Using averaging will cause this value to be more stable, but it will update more slowly.

Returns:: A scaled sample from the output of the oversample and average engine for this channel.

getChannel() → int¶

Get the channel number.

Returns:: The channel number.

getLSBWeight() → int¶

Get the factory scaling least significant bit weight constant.

Volts = ((LSB_Weight * 1e-9) * raw) - (Offset * 1e-9)

Returns:: Least significant bit weight.

getOffset() → int¶

Get the factory scaling offset constant.

Volts = ((LSB_Weight * 1e-9) * raw) - (Offset * 1e-9)

Returns:: Offset constant.

getOversampleBits() → int¶

Get the number of oversample bits previously configured.

This gets the number of oversample bits from the FPGA. The actual number of oversampled values is 2^bits. The oversampling is done automatically in the FPGA.

Returns:: Number of bits of oversampling previously configured.

static getSampleRate() → float¶

Get the current sample rate for all channels

Returns:: Sample rate.

getValue() → int¶

Get a sample straight from this channel.

The sample is a 12-bit value representing the 0V to 5V range of the A/D converter in the module. The units are in A/D converter codes. Use GetVoltage() to get the analog value in calibrated units.

Returns:: A sample straight from this channel.

getVoltage() → float¶

Get a scaled sample straight from this channel.

The value is scaled to units of Volts using the calibrated scaling data from GetLSBWeight() and GetOffset().

Returns:: A scaled sample straight from this channel.

initAccumulator() → None¶: Initialize the accumulator.

initSendable(builder: wpiutil._wpiutil.SendableBuilder) → None¶

isAccumulatorChannel() → bool¶

Is the channel attached to an accumulator.

Returns:: The analog input is attached to an accumulator.

kAccumulatorModuleNumber = 1¶

kAccumulatorNumChannels = 2¶

resetAccumulator() → None¶: Resets the accumulator to the initial value.

setAccumulatorCenter(center: int) → None¶

Set the center value of the accumulator.

The center value is subtracted from each A/D value before it is added to the accumulator. This is used for the center value of devices like gyros and accelerometers to take the device offset into account when integrating.

This center value is based on the output of the oversampled and averaged source from the accumulator channel. Because of this, any non-zero oversample bits will affect the size of the value for this field.

setAccumulatorDeadband(deadband: int) → None¶: Set the accumulator’s deadband.

setAccumulatorInitialValue(value: int) → None¶

Set an initial value for the accumulator.

This will be added to all values returned to the user.

Parameters:: value – The value that the accumulator should start from when reset.

setAverageBits(bits: int) → None¶

Set the number of averaging bits.

This sets the number of averaging bits. The actual number of averaged samples is 2^bits.

Use averaging to improve the stability of your measurement at the expense of sampling rate. The averaging is done automatically in the FPGA.

Parameters:: bits – Number of bits of averaging.

setOversampleBits(bits: int) → None¶

Set the number of oversample bits.

This sets the number of oversample bits. The actual number of oversampled values is 2^bits. Use oversampling to improve the resolution of your measurements at the expense of sampling rate. The oversampling is done automatically in the FPGA.

Parameters:: bits – Number of bits of oversampling.

static setSampleRate(samplesPerSecond: float) → None¶

Set the sample rate per channel for all analog channels.

The maximum rate is 500kS/s divided by the number of channels in use. This is 62500 samples/s per channel.

Parameters:: samplesPerSecond – The number of samples per second.

setSimDevice(device: int) → None¶

Indicates this input is used by a simulated device.

Parameters:: device – simulated device handle