AKC6955-Arduino Radio

Nowadays, we are accustomed to receiving the sound of online media. Do you still remember the feeling of listening to the radio? The music playing in the rustling background seems to be full of magic - you don't know where it comes from, you don't know what the next piece of music is, and you don't know if anyone else is listening to this ancient form of media with you. As a radio enthusiast, I love the mystery of radio and the experience of exploring this mystery myself.

This project is intended to provide a baseboard based on the AKC6955 radio DSP and Arduino pro mini, so that everyone can make their own programmable radio . 9 digital key interfaces are reserved for function selection, and Arduino is used as the main control to facilitate development.

The software part of this project adopts the design of https://github.com/pu2clr/AKC695X  . I would like to thank pu2clr and others for their contribution to the project. I personally transplanted it to STM32, see https://gitee.com/maaaaark/AKC695X-STM32 for details , but it has not been completely completed, so the STM32 hardware board is not available for this open source.

Since the software project is based on the MIT open source license, this hardware project is also open source based on the MIT license as a tribute to the software authors.

Embracing open source starts with me.

Notes are noted on the schematic

The core circuit in the schematic diagram has been verified by perforated board

The attachment contains the arduino project and exquisite BOM

7.25 project progress: The board is ready and has been welded. Picture: Circuit board changes: The circuit board before 7.24 was missing the arduino power supply. It has been added first, and the type-c has been replaced with a more commonly used in-line package, which has been optimized. FM receiving part wiring

A problem was discovered during testing

Warning! Problem description: The FM receiving part has a high probability of poor reception. After investigation, it was found that the ground wire and the FM receiving line have AC coupling characteristics. The earphones are grounded through the capacitor and will also bring signals to the FM receiving end and receive the sound. Speculation:

1. The wiring of the FM receiving part overlaps vertically with the copper layout or the distance is too small, resulting in AC coupling, which is highly unlikely. Improved in versions after 7.25
2. The solder mask layer falls off during soldering, and a large area of ​​copper is laid, causing a short circuit between GND and some lines, which is very likely. This time, the solder mask layer fell off easily (the temperature of the soldering iron did not exceed 300 degrees), and there were at least five peelings, causing the copper to be exposed. I personally feel that this is the most likely cause. Solution: No copper laying. The copper PCB for this project has been deleted.
3. The DSP chip is damaged. There is a small probability, because there have been successful receptions. The green indicator light in the picture indicates that there is a signal and the frequency has been locked.

Other additions: Since I am going to class on July 27, plus I am training at the electrician base and reviewing knowledge from the previous semester to prepare for the exam, I do not have enough energy and time to continue to complete the re-verification of the PCB project in August, September and October. I hope everyone can put it into practice. This open source fire is passed on and the project continues to be optimized.

New in 8.14:

1. Core function verification video has been released: BV1654y1m7da
2. PCB board display, overview and next plans: BV1Gf4y197Qt