diff --git a/README.md b/README.md index 70e63b3..dda5c27 100644 --- a/README.md +++ b/README.md @@ -7,7 +7,29 @@ Coming soon... ## Designs ### SmartKnob View -Premium SmartKnob experience. Under active development. Untested & unproven. +Premium SmartKnob experience. Under active development. + +Not recommended for general use yet (mechanical and electrical revisions are planned). + +Requires advanced soldering experience to build - reflow and small-pitch SMT soldering are required. + +Features: + - Powered by ESP32-PICO-V3-02 (Lilygo TMicro32 Plus module) + - 240x240 round LCD, protected by 39.5mm watch glass on rotor + - PCB flexure and strain gauges used for press detection (haptic feedback provided via the motor) + - 8 side-firing RGB LEDs (SK6812-SIDE-A) illuminate ring around the knob + - USB C (2.0) connector for 5V power and serial data/programming (CH340) + - VEML7700 ambient light sensor for automatic backlight & LED intensity adjustment + - Versatile back plate for mounting - use either 4x screws, or 2x 3M medium Command strips for mounting + - Front cover snaps on for easy access + +#### Demo video + + + + + +#### Exploded view ![Exploded view](doc/img/explodedv145.gif) @@ -20,6 +42,7 @@ Premium SmartKnob experience. Under active development. Untested & unproven. +Note: use white soldermask, for reflecting light from RGB LED ring around the knob. [Schematic](https://smartknob-artifacts.s3.us-west-1.amazonaws.com/master/electronics/view_base-schematic.pdf) @@ -58,6 +81,19 @@ Planned for the future. ## Component Info ### Magnetic encoders + +#### MT6701 (MagnTek) +Excellent sensor at a reasonable price - highly recommended. Less noisy than TLV493D, and more responsive (control loop is more stable) using SSI. + + - Lots of IO options - SSI, I2C, and ABZ - should offer good response latency + - SSI includes CRC to validate data + - No power-down or low-power options - may not be ideal for battery-powered devices + - Not available from US distributors (Mouser, Digi-Key) + +[Datasheet](http://www.magntek.com.cn/upload/MT6701_Rev.1.5.pdf) + +[Ordering (LCSC)](https://lcsc.com/product-detail/Angle-Linear-Position-Sensors_Magn-Tek-MT6701CT-STD_C2856764.html) + #### TLV493D (Infineon) A mediocre choice. Easy to prototype with using [Adafruit's QWIIC breakout board](https://www.adafruit.com/product/4366). @@ -71,27 +107,15 @@ There is also apparently a known silicon issue that causes the internal ADC to s be detected by: - Frame Counter (FRM) counter stucks and does not increment anymore. -In my experience testing 4 different Adafruit breakout boards, 2 of them (50%) regularly exhibit this lockup behavior within a minute or two of use. - -As of 2022-02-08, there is limited availability of this IC. +In my experience testing 4 different Adafruit breakout boards, 2 of them (50%) regularly exhibit this lockup behavior within a minute or two of use. It is possible to detect and auto-reset (and there is code in the project to do so), but it is slow and may cause undesirable jumps/delays if the sensor locks up often. [Datasheet](https://www.mouser.com/datasheet/2/196/Infineon_TLV493D_A1B6_DataSheet_v01_10_EN-1227967.pdf) -#### MT6701 (MagnTek) -Very promising based on the datasheet and initial tests. Seems to be less noisy than TLV493D, and more responsive (control loop is more stable) using SSI. - - - Lots of IO options - SSI, I2C, and ABZ - should offer good response latency - - SSI include CRC to validate data - - No power-down or low-power options - may not be ideal for battery-powered devices - - Not available from US distributors (Mouser, Digi-Key) - -[Datasheet](http://www.magntek.com.cn/upload/MT6701_Rev.1.5.pdf) - -[Ordering (LCSC)](https://lcsc.com/product-detail/Angle-Linear-Position-Sensors_Magn-Tek-MT6701CT-STD_C2856764.html) +#### ### Motor drivers #### TMC6300-LA -This is a relatively new IC and it's a perfect match! There generally aren't any other drivers (with integrated fets) that meet the requirements for the low-voltage and low-current motors used in this project. +This is a relatively new IC and it's a perfect match! There generally aren't any other drivers (with integrated fets) that meet the requirements for the low-voltage and low-current motors used in this project (DRV8316 might work, but has not been tested). Highlights: - 2-11V DC motor supply input