News: PCB development - I2C_mtrDrvr V1.0, servoDigitCtrlr, pxlBlck_multiPCB, XGZP6847_adapter and nanoPxl V1.4

I'm currently working on a few PCB projects and I would like to give you a little insight into them here. 🙂

I have all the boards presented below PCBWay.com have manufactured. They support my projects and provided me with the circuit boards for them. If you are looking for a reliable PCB manufacturer with very good service, I can PCBWay.com very recommended. 🙂

I2C_mtrDrvr V1.0

The I2C_mtrDrvr board has been on my desk for a while. It is part of the first experiments controlling the mechanics of WinDIY to simplify something. The following components are installed on the circuit board.

• DRV8830 I2C motor driver for controlling DC motors up to 1A
• ADS1115 I2C 4x ADC
• MCP9808 temperature sensor

A connected DC motor can be controlled using the DRV8830. I also have this driver on the first version of the controller WinDIY used to control the individual geared motors.

The also installed ADS1115 4x ADC can be used to read in up to four analog voltages. The first channel of the ADC is permanently connected to the shunt of the motor supply line. In this way, the current motor load can be determined and, if necessary, switched off in the event of an overload.

The MCP9808 temperature sensor is not necessary for the actual function. This provides the temperature on the PCB via the I2C bus.

The circuit works. You should only be careful with the FAULT line of the DRV8830, which is led out via the JST-PH connection, as it should not be connected to a GPIO without a series resistor. In a new version I will also accommodate this resistor on the PCB.

I will soon provide a structure article for the I2C_mtrDrvr here on Nerdiy.de. Until then you will find further information and pictures in the following paragraph.

servoDigitCtrlr

The servoDigitCtrlr board is intended as a control board for my servoDigit project (see video).

The goal is to be able to control the 28x SG90 servos (seven per digit). The following components are installed on the circuit board.

• 2x PCA9685 16x Port I2C PWM Expander
• 2x ADS1115 4x I2C ADC
• LM2596S step-down converter
• 1x WS2812 2x2mm RGB Led
• BME280 climate sensor
• MCP9809 temperature sensor
• DS3232M I2C RTC
• 2x RT9013 3.3V voltage regulator
• ESP32 Wroom as MCU

The first prototype works. The built-in JST-XH connector can also be connected directly to the balancer connection of a 4S lipo. Theoretically, the circuit or clock can also be powered by a battery. To save energy, the power supply of the installed sensors and actuators can also be controlled separately from the power supply of the ESP32.

Below is a video and a few photos of the first prototype.

pxlBlck_multiPCB

The pxlBlck_multiPCB is a very tightly populated four-layer board. An LED matrix of 10×10 WS2812 3.5×3.5mm LEDs can be installed on the underside.

There is space on the top for the following components.

• DS3232M RTC
• ESP32-Wrover-B MCU
• ADXL345 IMU
• MicroSD card slot
• MPR121 touch controller for up to 12 electrodes
• BME280 climate sensor
• USB-C connection including ESD protection and USB-serial converter which can be used to program the MCU
• MAX98357 I2S DAC including Class D amplifier
• QWIIC connection

The circuit board is supposed to be the new heart for mine pxlBlck platforms become. The plan is to also be able to play MP3 files from the built-in SD card and the Class D amplifier. In addition, inputs to control the pxlBlck can also be made via the 12 touch electrodes of the MPR121.

Using the QWIIC connection, other sensors and actuators with the same standard can also be connected. The board is ultimately supplied with up to 15W (5V/3A) via the USB-C connection.

XGZP6847_adapter

The XGZP6847_adapter board is a small adapter board that I use to set up my pick and place machine.

For this purpose, two XGZP6847 air pressure sensors can be installed on the board. These are intended to measure the pressure or negative pressure in the intake line to accommodate the components. This means the machine can automatically detect whether a recording process was successful or unsuccessful.

The measured pressure is output as a voltage between 0.5 and 4.5V. These voltages can be measured directly via the JST connector. Using the solder jumpers on the PCB, an optionally equipped ADS1115 can also be used to measure the voltages. The I2C bus is then accessible via the JST connector.

nanoPxl V1.4

The nanoPxl V1.4 board is the fourth iteration of the nanoPxl. This is an adapter board for the WS2811 that can be used to control three 5730 LEDs. This is intended as a stronger alternative to the well-known WS2812 LED, because I need a slightly brighter version for one of my projects.

You can find more information about this in the article Electronics – solder nanoPxl V1.1 SMD components or in the following video and pictures.