49 lines
1.2 KiB
Markdown
49 lines
1.2 KiB
Markdown
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# HX711 Module
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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.
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Note: To save ROM image space, the hx711 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 compatability 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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