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ESP8266 low power DHT11 temperature and moisture remote sensor

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- March 13, 2020

I have a problem with moisture in my loft. After planning some intervention, I wanted a way to remotely monitor the humidity and temperature up there, and to visualise the data on a server.

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arduino29 quadcopter17 Atmega328p16 ESP826612 ESP-01S10 8-bit computer9 Make9 IoT6 MicroPython5 bluetooth5

nRF24l015 ESP-12E3 assembly3 attiny853 bootloaders3 fuses3 mario3 ARM2 Kalman filter2 MS56112 STM322 Twitter2 DHT111 Lua1 Raspberry Pi1 atmega32u41

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8-Bit Computer: WS2812B LED module

- March 29, 2021

Every 8-bit computer needs some kind of output display, whether this is a LCD display, or a 7-segment display, it needs some way of displaying data to the outside world. Wouldn't it be cool to have a pretty RGB LED display as a way of not only showing the output of computation, but to act as a screen for showing animations, even playing simple games? At the very least it would be cool to have a kind of "RAM visualizer" to show the contents of RAM for debugging purposes. With that in mind, I recently came across a post on the timing for WS2812 LEDs, part 1 and part 2 , in which the blog post author Tim sets out the limits of the WS2812 LED protocol and shows they are rather flexible and not as stringent as the official datasheet suggests (i.e. see here for WS2812b datasheet or here ). Further he suggests a way of controlling LED strips with a simple timing cycle, encoding either a 0 or a 1 bit, like so: Tim then goes on to write some assembly language to control WS2812...

PS2 controller as a radio controller!

- June 11, 2019

Turning a PS2 controller into a wireless radio controller with Arduino Mini and an nRF24l01 radio module I have previously described a project to transmit PS2 controller signals by radio . The project featured an Arduino Nano that read the PS2 signals and transmitted them with an nRF24l01 module. Recently I have been inspired to incorporate the battery, charging circuit and Arduino right into the controller - heavily inspired by this project here:

Arduino and Raspberry Pi serial communciation

- June 30, 2019

Want to hook up your Arduino to your Raspberry Pi and send data between the two? Read on! So you have your Arduino robot, or weather station and you want to send data back and forth with a Raspberry Pi? The hardware hookup is really easy, but we have to configure a few things on the Pi. Hardware connections We'll use the serial UART pins on the Raspberry Pi Zero GPIO for this example, and transfer data from an Arduino to a Raspberry Pi zero, though all Raspberry Pis and Arduinos are capable of this feat. The UART is a common serial communication protocol comprised of two pins labelled, RX (receive data pin) and "TX" (transmit data pin). Wiring is easy - hook up the desired RX pin on the Arduino to the Raspberry Pi TX pin, and the Arduino TX to the Raspberry Pi RX pin. As always, make sure you connect the ground line between the Arduino and the Raspberry Pi. If the particular Arduino model you are using is powered by 5V (find out by measurin...

ESP8266: Minimum I2S code

- September 15, 2018

Question: What's the most convoluted way to flash an LED on an ESP8266? Answer : Using DMA (Direct Memory Access) and to output to a GPIO using the I2S protocol of course! Outputting memory straight to an LED using I2S

Getting started with the Pro Micro Arduino Board

- April 12, 2019

This is a brief guide to getting started with the Pro Micro Arduino Board (Atmega32U4) - not to be confused with the Pro Mini (which utilises the Atmega328P)! Note that the Pro Micro board comes in two flavours/flavors - 5V @ 16 MHz and 3.3V @ 8 MHz, so make sure you know which you have before getting started. It should be indicated on the bottom silkscreen of the bottom, or you could take a voltmeter and measure VCC against GND - it will be either 5V or 3.3V.

8-Bit Computer: UART Transceiver for breadboard computer

- July 29, 2020

You art UART I have an increasing fascination with building 8-bit computers from TTL chips, sparked by the excellent Ben Eater series on YouTube , and deepened by a variety of examples on Hackaday . In the process of designing/building my own 8-bit computer, I wondered how easy it would be to implement a UART transceiver purely out of basic 7400 series ICs... The finished design: UART Transceiver built from 7400 series ICs.

Interfacing a (micro)SD card with an Atmega328 microcontroller

- September 26, 2015

Interfacing a microSD card with an Atmega328 microcontroller Hooking up an SD card (or microSD card) to your AVR project will seriously increase the amount of data storage you can access. I wanted to stream WAV files from an SD card for an audio project I was working on. I'm not going to delve into FAT16/FAT32 architecture or the SD card SPI interface in this post, but working on the principle that Life's too short to reinvent the wheel, there are libraries available for reading and writing to SD cards with Atmel microcontrollers. First things first, we need to physically connect our SD card to the controller. I'm actually using a microSD card to save space on my PCB, but I'm using a microSD card adapter so this will apply to SD cards equally. Grab a soldering iron, your SD card (/microSD card adapter) and a 7 pin header and solder like so: Tin the header pins and be careful not to melt the plastic and bridge the connections. Using a put...

Height and vertical velocity Kalman filtering on MS5611 barometer

- June 01, 2017

Height and vertical velocity from a MS5611 barometer Steps towards vertical flight control This isn't a post explaining how Kalman filters work, I assume some working knowledge. Instead I wanted to record the process of developing a Kalman filter to derive both the height and the vertical velocity of a quadcopter using a MS5611 barometer, as it may be useful to others. After recording some flight data on my quadcopter EEPROM, I then spat the output to a PC for post-processing and model training. In Python I used a Kalman class to generate the following Kalman filter ( Wikipedia: Kalman filter ) based on the barometric height data.

Recovering ATMEGA328p chip from external clock fuse set

- March 13, 2016

A quick post of tragedy and triumph! Whilst breadboarding a new project with an Atmega328p chip (the heart of some of the Arduino ecosystem), I wanted to configure the AVR "fuses" (a desperately misleading term!) in order to use an external 16 MHz crystal, rather than the default internal 8 MHz oscillator. This is straight forward and something I've done before. Using the excellent fuse calculator , I wanted to get cracking and rushed in without double checking my fuse selection. Big mistake! I saw the option "external clock" (CKSEL=0000 SUT=00), and thought "great, that's it", also unselecting the CKDIV8 option (bit 7), generates the LOW fuse = 0xC0 and the HIGH fuse = 0xD9. Two right mistakes here! First of all the small one: Selecting a box corresponds to setting the bit to '0', rather than '1', i.e. *unselecting/unticking* the CKDIV8 boxes will SET this bit as true (and divide the clock signal by 8). It can't be...

ATtiny Mario

- January 14, 2020

ATtiny85 Mario Challenge! The ATtiny85 microcontroller is a capable but compact AVR. However with only 8K of program memory, 512 bytes of EEPROM, 512 of SRAM and only 8 pins (3 of which are dedicated to the usual suspects of Vcc, GND and RESET), it best suited to performing tasks where memory demands are not large, and only a few pins are required for interfacing.