creativecontrol-circuitpython-ltc166x 1.2.3

Introduction

CircuitPython library for control of LTC1665 8-bit and LTC1660 10-bit 8 channel DACs from Linear Technologies.

LTC166X datasheet

Multiple LTC1665/LTC1660’s can be controlled from a single 3-wire serial port (i.e., SCK, DIN and CS/LD) by using the included “daisy-chain” facility. A series of n chips is configured by connecting each DOUT (except the last) to DIN of the next chip, forming a single 16n-bit shift register. The SCK and CS/LD signals are common to all chips in the chain. In use, CS/LD is held low while n 16-bit words are clocked to DIN of the first chip; CS/LD is then pulled high, updating all of them simultaneously.

Dependencies

This driver depends on:

• Adafruit CircuitPython

• Bus Device

Please ensure all dependencies are available on the CircuitPython filesystem. This is easily achieved by downloading the Adafruit library and driver bundle or individual libraries can be installed using circup.

Installing from PyPI

On supported GNU/Linux systems like the Raspberry Pi, you can install the driver locally from PyPI. To install for current user:

pip3 install creativecontrol-circuitpython-ltc166x

To install system-wide (this may be required in some cases):

sudo pip3 install creativecontrol-circuitpython-ltc166x

To install in a virtual environment in your current project:

mkdir project-name && cd project-name
python3 -m venv .venv
source .env/bin/activate
pip3 install creativecontrol-circuitpython-ltc166x

Installing to a Connected CircuitPython Device with Circup

Make sure that you have circup installed in your Python environment. Install it with the following command if necessary:

pip3 install circup

With circup installed and your CircuitPython device connected use the following command to install:

circup install creativecontrol_circuitpython_ltc166x

Or the following command to update an existing version:

circup update

Usage Example

import time
import board
import creativecontrol_circuitpython_ltc166x

ltc1665 = creativecontrol_circuitpython_ltc166x.LTC1665(csel=board.GP1, sck=board.GP2, mosi=board.GP3, debug=True)

dac_values = [1, 3, 7, 15, 31, 63, 127, 255]

while True:
     print('writing dac values ', time.monotonic())
     ltc1665.write_dac_values(dac_values)
     time.sleep(4)
     print('off')
     ltc1665.write_dac_values([0]*8)
     time.sleep(4)

Documentation

API documentation for this library can be found on Read the Docs.

For information on building library documentation, please check out this guide.

Tutorial

A tutorial on controlling daisy-chained LTC166X DACs can be found on my website creativecontrol.

Contributing

Contributions are welcome! Please read our Code of Conduct before contributing to help this project stay welcoming.