Some of my recent Open Source projects with STM32F4 microcontrollers:
Decoding Radio Time Signals with an STM32F4
The project points out how to decode time station signals with an off-the-shelf decoder, an STM32F4 MCU and an LCD display.
ISM 433MHz data radio transmitter/receiver device (RFM12B, STM32F4)
The project describes a transmitter and a receiver for low-range data communication on one of the ISM bands (in this case 433MHz). Data is transmitted using FSK (frequency shift keying) in the transmitter, then being decoded in the receiver and displayed on an OLED.
A low complexity “anti-theft” GPS/GSM tracker for RVs
A simple device will be presented that can be installed into a “theft-prone” vehicle (caravan, RV, boat etc.) to detect and respond to unlawful movement of the vehicle like theft etc. It can be seen as a starting point for own further developments and is composed from off-the-shelf modules only:
Direct Frequency Modulation (FM) with fast DDS and STM32F4
An alternative method of generating frequency modulated radio signals will be shown. This project is part of a commercial project and intended for implementing an AFS/FSK data transmission line for exchanging weather data from various stations to a master station with in the 2.4 GHz frequency spectrum. As receivers for narrow band FM were already installed, the transmitter had to use this modulation method as mandatory requirement.
Dual Audio Frequency Generator with AD9850 and STM32F4
Dual audio tone modulation is a standard method for testing linearity of single sideband (SSB) transmitters. Usually 2 analog audio oscillators are used. With this project instead using analog oscillators a method of generating the two audio frequencies by the means of DDS will be described. The dual audio frequency generator is setup from standard modules.
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