herosdevices.hardware.raspberrypi.waveshare

Driver for Waveshare SBC/microcontroller extension boards.

Module Contents

class herosdevices.hardware.raspberrypi.waveshare.WaveshareADS1256(spi_bus: int = 0, spi_device: int = 0, rst_pin: int = 18, drdy_pin: int = 17, gain: int = 1, drate: str = '2000SPS', vref: float = 5.0, channel_name_map: dict[str, str] | None = None)[source]

Bases: herosdevices.interfaces.atomiq.ADC

This class represents one channel of the Waveshare ADS1256 ADC board.

Note

Concurrent access to the SPI device is not possible. This means only one object with a given spi_bus and spi_device can exist.

If you would like to access individual channels of this ADC consider creating objects of :class:WaveshareADS1256Channel in addition to an object of this class.

Parameters:

  • spi_bus – number of the SPI bus

  • spi_device – number of the SPI device in bus.

  • gain – gain to set in the PGIA

  • drate – conversion rate of the ADS1256. See .ads1256.ADS1256_DRATE for valid values

  • vref – Reference voltage given to the ADC. Usually 3.3V or 5V

  • samples – number of samples to average when sending out measured values as heros datasource

  • channel_name_map – dict to map the internal names of the pin (AIN0…AIN7) to user-definable names. The names are used if the operated as HEROS datasource. Example: {“AIN0”: “my_voltage”, “AIN2”: “custom_sensor_3”}

gain
drate
vref = 5.0
channel_name_map
channel_name_map_reverse
get_samples(samples: int = 1, channel: str = '', neg_pin: str = 'AINCOM') → list[float][source]

Measure the given number of samples from the given channel.

Parameters:

  • samples (int) – Number of samples.

  • channel (str) – Name of the pin where the positive end of the voltage is applied

  • neg_pin (str) – Name of the pin where the negative end of the voltage is applied

Returns:

Measured voltage in volts.

Return type:

float

measure(samples: int = 1, channel: str = '', neg_pin: str = 'AINCOM') → float[source]

Measure the voltage by averaging multiple ADC samples.

Parameters:

  • samples (int) – Number of samples to average.

  • channel (str) – Name of the pin where the positive end of the voltage is applied

  • neg_pin (str) – Name of the pin where the negative end of the voltage is applied

Returns:

Measured voltage in volts.

Return type:

float

class herosdevices.hardware.raspberrypi.waveshare.WaveshareADS1256Channel(waveshare_ads1256: WaveshareADS1256, pos_pin: str, neg_pin: str = 'AINCOM', samples: int = 1)[source]

Bases: herosdevices.interfaces.atomiq.ADCChannel

A Single Channel of the Waveshare ADS1256 ADC board.

Parameters:

  • waveshare_ads1256 – Object or HERO of class WaveshareADS1256

  • posPin – Name of the pin receiving the positive voltage. I.e. AIN0 … AIN7 or AINCOM

  • negPin – Name of the pin receiving the negative voltage. I.e. AIN0 … AIN7 or AINCOM. For non-differential measurements this is usually AINCOM.

adc
pos_pin
neg_pin = 'AINCOM'
samples = 1
measure(samples: int | None = None, cached: bool = False, channel: str = '') → float[source]

Measure voltage at the current channel.

Parameters:

  • samples – Number of samples to average.

  • cached – not used

  • channel – not used