Alarm unit for limit switches or flow switches

Have you ever faced the frustration of dealing with an overflowing tank or a pump running dry? These unexpected events can result in costly damage and inconvenience. A reliable floater switch alarm system can provide early warnings, allowing you to take prompt action and prevent further issues. This project guides you through building a do-it-yourself floater switch alarm system using a PIC12F508 microcontroller.

The circuit for this project is relatively simple and requires very few components. The system is designed to operate with a 12V DC power supply and utilizes a 230V AC buzzer unit for audible alerts.

Prototype version of the alarm controller.

The circuit includes a mute function that allows you to temporarily silence the alarm for a specified duration. Additionally, a built-in timeout mechanism ensures continuous alarm activation if the floater switch remains closed for an extended period, indicating a potential emergency. This project is suitable for various applications, including home or industrial monitoring, and environmental monitoring.

The firmware for the microcontroller will control the operation of the alarm system. It should perform the following tasks:

Monitor the floater switch: Continuously read the input pin from the floater switch.
Activate the alarm: If the floater switch detects a change in water level (e.g., rising water), activate the buzzer or alarm.
Mute function: Allow the user to temporarily mute the alarm by pressing a button.
Timeouts: If the alarm remains active for an extended period, it may indicate a serious issue.

The firmware for this project is developed using the MPLAB X IDE and the XC8 C compiler. The latest firmware source code is available in the firmware directory of the project repository. The compiled firmware is also available in the release section of the project repository.

To protect the electronic components from moisture and other environmental factors, it is recommended to enclose the system in a waterproof enclosure. In our prototype build, we use an 100mm × 68mm × 50mm project enclosure to mount this controller.

This is an open hardware project. All the project firmware source code, design files, and compiled binaries are available on the GitHub project page.

Comments

CD2003 - yet another simple FM radio receiver

In the last few days, we are looking for some simple FM radio receiver to integrate into one of our ongoing projects. For that, we try several FM radio receiver ICs including TDA7000, CD2003/TA2003/TA8164, CXA1019, and KA22429. Out of all those chips we select CD2003 (or TA2003/TA8164) based receiver for our project because of its simplicity and outstanding performance. Except to CD2003, Sony CXA1019 also perform well but we drop it because of its higher component count. We design our receiver based on Toshiba TA2003 datasheet and later we try TA8164 and CD2003 with the same circuit. Either CD2003 or TA8164 can directly replace TA2003 IC, and as per our observations, TA8164 gives excellent results out of those 3 chips. A prototype version of CD2003 FM radio receiver The PCB design and schematic which we used in our prototype project are available to download at google drive (including pin-outs of crystal filters and inductors ). Except for CD2003 IC, this receiver consist

Arduino superheterodyne receiver

In this project, we extend the shortwave superheterodyne receiver we developed a few years ago . Like the previous design, this receiver operates on the traditional superheterodyne principle. In this upgrade, we enhanced the local oscillator with Si5351 clock generator module and Arduino control circuit. Compared to the old design, this new receiver uses an improved version of an intermediate frequency amplifier with 3 I.F transformers. In this new design, we divide this receiver into several blocks, which include, mixer with a detector, a local oscillator, and an I.F amplifier. The I.F amplifier builds into one PCB. The filter stage, mixer, and detector stages place in another PCB. Prototype version of 455kHz I.F amplifier. In this prototype build, the Si5351 clock generator drives using an Arduino Uno board. With the given sketch, the user can tune and switch the shortwave meter bands using a rotary encoder. The supplied sketch support clock generation from 5205kHz (tuner frequ

Calculator for audio output transformers

Audio output transformers are heavily used in a vacuum tube and some (older) transistor base audio power amplifiers, but these days output transformer are quite hard to find and expensive item. For homebrew projects, the best option is to construct those transformers by ourselves and this script helps to calculate winding parameters for those transformers. This " AF output transformer calculator " script is written using Python and it works with most of the commonly available Python interpreters . The script is available to download at google drive under the terms of GNU General Public License version 3.0 . Homebrewed 25k: 4 output transformer Once supplied the input parameters this script provides a winding ratio, the number of turns required for primary and secondary winding and required copper wire gauges for both primary and secondary windings, etc. We construct several AF output transformers based on results of this script, which including transformers for M