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.
This module provides access to an [HX711 load cell amplifier/ADC](https://learn.sparkfun.com/tutorials/load-cell-amplifier-hx711-breakout-hookup-guide). 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.
Note: To save ROM image space, this module is not compiled into the firmware by default.
## hx711.init()
## hx711.init()
Initialize io pins for hx711 clock and data.
Initialize io pins for hx711 clock and data.
#### Syntax
#### Syntax
`hx711.init(clk,data)`
`hx711.init(clk,data)`
#### Parameters
#### Parameters
-`clk` pin the hx711 clock signal is connected to.
-`clk` pin the hx711 clock signal is connected to
-`data` pin the hx711 data signal is connected to.
-`data` pin the hx711 data signal is connected to
#### Returns
#### Returns
`nil`
`nil`
...
@@ -24,6 +23,7 @@ Initialize io pins for hx711 clock and data.
...
@@ -24,6 +23,7 @@ Initialize io pins for hx711 clock and data.
-- Initialize the hx711 with clk on pin 5 and data on pin 6
-- Initialize the hx711 with clk on pin 5 and data on pin 6
hx711.init(5,6)
hx711.init(5,6)
```
```
## hx711.read()
## hx711.read()
Read digital loadcell ADC value.
Read digital loadcell ADC value.
...
@@ -32,14 +32,14 @@ Read digital loadcell ADC value.
...
@@ -32,14 +32,14 @@ Read digital loadcell ADC value.
`hx711.read(mode)`
`hx711.read(mode)`
#### Parameters
#### 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` 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 |
|mode | channel | gain |
|-----|---------|------|
|-----|---------|------|
| 0 | A | 128 |
| 0 | A | 128 |
#### Returns
#### Returns
a number (24 bit signed ADC value extended to the machine int size.)
a number (24 bit signed ADC value extended to the machine int size)