Digital Potentiometer (POT)

The Digital Potentiometer uses a resistor array to achieve a 0-127 step range between its high (RH) and low value (RL). In most cases these are wired to the same logic high and low. Thus, providing a POT output (on RW) for analog usage in the RH-RL range.

In addition to the controllable wiper value (via WR) the device provides the ability to set the initialization value on startup. This is provided via a mode change such that writes to the wiper value are preserved in a persistent storage on the chip (withing IVR on the EEPROM).

This set-and-update mode while useful for setting persistent values over power loss also comes with increased delay in update.

⚠️ mode changes to the control register (CR) do not take effect until the next write phase

⚠️ it is not recommended to update both CR and WR in a single update, although it is supported

import { I2CAddressedBus } from '@johntalton/and-other-delights'
import { DS3502 } from '@johntalton/ds3502'

const bus = /* I2CBus */
const device = new  DS3502.from(new I2CAddressedBus(bus, 0x28))

const { persist } = await device.getControl()

await device.setWiper(42)