Category: hardware

  • Lessons learnt from ESP NOW

    For those of you who aren’t aware of ESP NOW, it’s a communication protocol developed by Espressif for their ESP modules. What began as a simple “hook up my plant lights to HomeKit”, turned into a massive home grown firmware, but more about that in another post. I’ve successfully setup a bunch of ESP 8266…

  • Sending OTA updates over WiFi to your ESP8266

    This Christmas, I added a whole bunch of lights powered by 5V power sources. My goal was to switch them on at sunset, and switch them off on sunrise, by using a MOSFET for power control :) While I was doing this, I wanted to send OTA updates of my Lua files to the ESP8266…

  • nRF52840 – CircuitPython 5.0.0 pinout

    I recently got CircuitPython running on my SparkFun nRF52840 Pro Mini. Compared to what SparkFun says the pin mappings should be, I found them to be quite different. Perhaps they changed with CircuitPython 5.0.0? Here’s what the pin mapping looks like, when superimposed over SparkFun’s pinout diagram: Sources: https://learn.sparkfun.com/tutorials/nrf52840-development-with-arduino-and-circuitpython https://github.com/adafruit/circuitpython/blob/0f003ac5b8312fafb120e86e05eefd2431014d8c/ports/nrf/boards/sparkfun_nrf52840_mini/pins.c

  • nRF52840 – flashing the s340 v6.1.1 SoftDevice

    This post is a work in progress (WIP). The result of this experiment is a success. I have flashed my SparkFun nRF52840 mini, and I’m able to run the bicycle combined speed & cadence sensor example. Before we begin,  a big hats off to Charles, who brought support for the SparkFun board I have to the…

  • MPU 6050 and it’s DMP over time

    Using Jeff’s brilliant library for using the DMP on the MPU 6050, here are graphs of the DMP filling the FIFO buffer at 200 Hz, 100 Hz, and 50 Hz. At 200 Hz, I found that while the MPU did interrupt my Arduino Due at 200 Hz, I could only read off the FIFO at…

  • Arduino Due – Absolute Maximum Ratings

    The table below lists the maximum current which can be sourced or sinked for a given pin on an Arduino Due board: Due Pin Number SAM3X Pin Name Mapped Pin Name IOH (or ISOURCE) in mA IOL (or ISINK) in mA 0 PA8 RX0 3 6 1 PA9 TX0 15 9 2 PB25 Digital Pin…