49 lines
1.2 KiB
Markdown
49 lines
1.2 KiB
Markdown
# 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
|
|
```lua
|
|
-- 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
|
|
```lua
|
|
-- Read ch A with 128 gain.
|
|
raw_data = hx711.read(0)
|
|
```
|