Shared Projects by PeskyProducts

Breakout board for nRF51822 SoC with Cortex M0 processor and Bluetooth LE 2.4 GHz radio. Also on board are Bosch’s BMP280 pressure sensor and Invensense’s MPU9250 9 DoF motion sensor, and MAX1555 LiPo battery charger with USB (charging only). Replaced TLV70733 200 mA 3V3 regulator with MIC5528 500 mA 3V3 regulator. LED indication for 3V3 on, battery charging, and GPIO-controlled rgb LED. Side through-holes for I2C, UART, SWD program port and 12 GPIOs.

ST Microelectronic’s M41T62 ultra-low-power real time clock coupled with Bosch’s BME280 pressure, humidity, and temperature sensor and ST’s M2402DRC 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 512 Hz square-wave output allows the Teensy 3.1 microcontroller to make periodic calibration updates to the RTC calibration register so the clock is continuously compensated for maximum (~2 ppm or 1 minute a year) accuracy. The Taiyo Yuden PAS3225 2.6V 14 mF super capacitor and 1N4148 diode 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! Went back to standard 1N4148 diode.

Breakout board to test magnetometer performance. Magnetometers include Honeywell’s HMC5883, Asahi Kasei’s AK8963C, and ST Microelectronics' LIS3MDL. Board allows comparative test of basic performance and test of effects of different mag data on EM7180 sensor fusion using the MPU6500 accel/gyro. Fixed LIS3MDL package error.

Small board for direct mounting on the teensy 3.x with the nRF51822 communicating with the teensy via hardware SPI like Adafruit’s SPI Friend. Should allow use of Adafruit’s software to create Teensy-based bluetooth peripheral nodes.

Programmable LP55231 led driver with three common-cathode Kingbright rgb leds in a standard Teensy 3.1 add-on board. Board can be mounted onto a teensy or used on a breadboard, and can be operated from the Teensy host or as a stand-alone, LiPo-battery-operated device. Vin is between 2.7 and 5.5 V. Switched red leds to D7-9 since driven directly by VIN as per data sheet.