Crates.io | mcp4x |
lib.rs | mcp4x |
version | 1.0.0 |
source | src |
created_at | 2019-02-09 13:07:35.890521 |
updated_at | 2024-06-24 07:05:10.873743 |
description | Platform-agnostic Rust driver for the MCP4x digital potentiometers. |
homepage | https://github.com/eldruin/mcp4x-rs |
repository | https://github.com/eldruin/mcp4x-rs |
max_upload_size | |
id | 113726 |
size | 43,990 |
This is a platform-agnostic Rust driver for the MCP41xxx and MCP42xxx SPI
digital potentiometers (digipot), based on the embedded-hal
traits.
This driver allows you to:
set_position()
.shutdown()
.The MCP41XXX and MCP42XXX devices are 256-position, digital potentiometers available in 10 kΩ, 50 kΩ and 100 kΩ resistance versions. The MCP41XXX is a single-channel device and is offered in an 8-pin PDIP or SOIC package. The MCP42XXX contains two independent channels in a 14-pin PDIP, SOIC or TSSOP package. The wiper position of the MCP41XXX/42XXX varies linearly and is controlled via an industry-standard SPI interface.
The devices consume <1 μA during static operation. A software shutdown feature is provided that disconnects the "A" terminal from the resistor stack and simultaneously connects the wiper to the "B" terminal. In addition, the dual MCP42XXX has a SHDN pin that performs the same function in hardware. During shutdown mode, the contents of the wiper register can be changed and the potentiometer returns from shutdown to the new value. The wiper is reset to the mid-scale position (80h) upon power-up. The RS (reset) pin implements a hardware reset and also returns the wiper to mid-scale.
The MCP42XXX SPI interface includes both the SI and SO pins, allowing daisy-chaining of multiple devices. Channel-to-channel resistance matching on the MCP42XXX varies by less than 1%.
This driver should be compatible at least with the devices: MCP41010, MCP41050, MCP41100, MCP42010, MCP42050 and MCP42100.
Datasheet:
To use this driver, import this crate and an embedded_hal
implementation,
then instantiate the appropriate device.
In the following examples an instance of the device MCP41x will be created
as an example. Other devices can be created with similar methods like:
Mcp4x::new_mcp42x(...)
.
Please find additional examples using hardware in this repository: driver-examples
use mcp4x::{Channel, Mcp4x};
use embedded_hal_bus::spi::ExclusiveDevice;
use linux_embedded_hal::{Delay, SpidevBus, SysfsPin};
fn main() {
let spi = SpidevBus::open("/dev/spidev0.0").unwrap();
let chip_select = SysfsPin::new(25);
let dev = ExclusiveDevice::new(spi, chip_select, Delay);
let mut mcp41x = Mcp4x::new_mcp41x(dev);
mcp41x.set_position(Channel::Ch0, 50).unwrap();
// Get SPI device back
let _dev = mcp41x.destroy_mcp41x();
}
For questions, issues, feature requests like compatibility with similar devices and other changes, please file an issue in the github project.
Licensed under either of
at your option.
Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.