This is the firmware repo for the Core Electronics Makerverse Load Cell ADC MicroPython module.

See the Makerverse Load Cell Kit for more documentation.

The example below assumes that Sclk and Dout are connected to GPIO16 and GPIO17, respectively. It reads values from the load cell ADC and prints an estimate of the weight in grams.

For higher accuracy, the calibration procedure in the guide can be followed.

from machine import Pin
from Makerverse_hx710c import Makerverse_hx710c
from time import sleep_ms

LC = Makerverse_hx710c(dataPin = Pin(17), clkPin = Pin(16), calibration=1.4397e-3)

while True:
    Data = LC.read_hx710_calibrated()
    print("{:+.3f} g".format(Data))
    sleep_ms(90)

Returns a Makerverse_hx710c object to interface with a Load Cell ADC module connected to the specified pins.

Returns a floating point value equal to the mass measured by the load cell in units of grams. The accuracy of the returned value depends on the accuracy of the calibration.

This function is blocking and will wait for an ADC reading to become available before returning. It can take up to 100ms to return.

Returns a the next available raw ADC value minus the zero point. The raw value is a 24-bit 2's complement number from 0x800000 to 0x7FFFFF (decimal -8388608 to 8388607). The zero point is typically relatively close to zero but can cause the return value to exceed the specified range.

This function is blocking and will wait for an ADC reading to become available before returning. It can take up to 100ms to return.

Returns the average of several readings to achieve greater measurement precision. Note that the accuracy (derived from the accuracy of the calibration procedure) remains unchanged.

When using this function you may wish to consider first taking a "large" number of samples of the zero point. The zero point measured at initialisation only uses an average of 10 readings.

Note that the noise in ADC readings is closely Gaussian. As such, noise decreases with the square root of the number of samples in the average. To halve the error the number of averaged samples must increase by a factor of 4.

This function is blocking and will wait for all required ADC readings to become available before returning. It can take up to 100ms per averaged sample to return.

Note that 32 samples can be buffered in the PIO' FIFO. If readings are not being streamed from the ADC then 32 samples should be read and discarded directly before calling this function to ensure that the most recent values are used.

This method performs a calibration procedure to measure the sensitivity of the load cell and load cell ADC in units of grams per least significant bit.

The calibration procedure requires a calibration reference mass. The Makerverse Load Cell Kit contains a 50g mass with an error far below the 0.1g resolution of the hardware provided with the Makerverse Load Cell Kit.

If requied, 50g calibration mass is available individually and has SKU CE08490.

This method can be used with a calibration mass of any size. The ideal mass is one equal to the full scale measurement of the load cell, in the kit's case 3kg, but this is impractical for the kit.

Multiple 50g masses can be placed on the load cell platform simultaneously for increased accuracy. The 0.1g accuracy is only realised for measurements below the calibration mass.

With a single 50g calibration mass the approximate absolute error at 3kg is around +/- 6g (0.2%).

Resets the "zero" point to the currently measured weight.