nodemcu-firmware/docs/en/modules/hx711.md

HX711 Module

This module provides access to an HX711 load cell amplifier/ADC. The HX711 is an inexpensive 24bit ADC with programmable 128x, 64x, and 32x gain. Currently only channel A at 128x gain is supported.

Note: To save ROM image space, the hx711 module is not compiled into the firmware by default.

hx711.init()

Initialize io pins for hx711 clock and data.

Syntax

hx711.init(clk,data)

Parameters

• clk pin the hx711 clock signal is connected to.
• data pin the hx711 data signal is connected to.

Returns

nil

Example

-- Initialize the hx711 with clk on pin 5 and data on pin 6
hx711.init(5,6)

hx711.read()

Read digital loadcell ADC value.

Syntax

hx711.read(mode)

Parameters

• mode ADC mode. This parameter is currently ignored and reserved to ensure backward compatability if support for additional modes is added. Currently only channel A @ 128 gain is supported.

mode	channel	gain
0	A	128

Returns

a number (24 bit signed ADC value extended to the machine int size.)

Example

-- Read ch A with 128 gain.
raw_data = hx711.read(0)