Shared Projects by PeskyProducts

ST Microelectronic’s ultra-low-power real time clock coupled with Bosch’s BME280 pressure, humidity, and temperature sensor and ST’s M2402DFC 2Mbit EEPROM in an appallingly small add-on board for Teensy 3.1. Power is supplied via digital write to general GPIO pins since the total power requirement never exceeds 2 mA. Communication is via I2C and there are 4K7 pullup resistors on board. The temperature sensor allows the Teensy 3.1 microcontroller to make periodic calibration updates to the RTC calibration register so the clock remains temperature compensated for maximum (~2 ppm or 1 minute a year) accuracy. The clock outputs the usual date, days, hours, minutes, etc. but also outputs tenths of seconds as well as hundredths of a second.The on-board EEPROM is useful for data logging and storing alarm patterns (music) for output to a small speaker. With 2 Mbits (256 kBytes), lots of data can be logged and dozens of alarm sounds can be stored; one for every occasion! Added Taiyo Yuden PAS3225 2.6V 14 mF super capacitor and Comchip low forward voltage Schottky diode to provide power to the RTC time keeper even when disconnected from the microcontroller. The PAS3225 5 microAhour super cap can run the RTC (which needs ~330 nA at 2.6 V) for about 18 hours. The board is now a tiny weather logging station: pressure, temperature, and humidity can be logged once per minute for 15 days! IRQ pullup on the host side.

Test board for nRF51822 CFAC.

Simple DC brushed motor driver using TI’s DRV8837 1.8 A PWM-controlled H-Bridges. Board is designed to be mounted onto a Teensy 3.X although it can also be used on a breadboard. The H-bridges allow the motors to be driven both forward and reverse, with braking and coasting options as well. SLEEP pin HIGH enables the motors. Added zero resistor jumper to connect VM and VCC and added GND vias.

Test board for Toshiba’s BLDC motor controller. Added GND vias, moved caps slightly. Added GND vias on EPAD.

Reattempt