52 lines
1.5 KiB
Markdown
52 lines
1.5 KiB
Markdown
# HX711 Module
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| Since | Origin / Contributor | Maintainer | Source |
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| :----- | :-------------------- | :---------- | :------ |
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| 2015-10-09 | [Chris Takahashi](https://github.com/christakahashi) | [Chris Takahashi](https://github.com/christakahashi) | [hx711.c](../../app/modules/hx711.c)|
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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.
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Note: To save ROM image space, this module is not compiled into the firmware by default.
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## hx711.init()
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Initialize io pins for hx711 clock and data.
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#### Syntax
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`hx711.init(clk, data)`
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#### Parameters
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- `clk` pin the hx711 clock signal is connected to
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- `data` pin the hx711 data signal is connected to
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#### Returns
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`nil`
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#### Example
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```lua
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-- Initialize the hx711 with clk on pin 5 and data on pin 6
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hx711.init(5,6)
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```
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## hx711.read()
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Read digital loadcell ADC value.
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#### Syntax
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`hx711.read(mode)`
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#### Parameters
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`mode` ADC mode. This parameter is currently ignored and reserved to ensure backward compatibility if support for additional modes is added. Currently only channel A @ 128 gain is supported.
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|mode | channel | gain |
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|-----|---------|------|
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| 0 | A | 128 |
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#### Returns
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a number (24 bit signed ADC value extended to the machine int size)
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#### Example
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```lua
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-- Read ch A with 128 gain.
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raw_data = hx711.read(0)
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```
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