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7-segment display and STM32 using ChibiOS

7-segment display and STM32 using ChibiOS

We have already introduced MAX7219 in STM32, ChibiOS and a 8×8 LED Matrix, so we are going to jump directly to code section. For convenience we just report link to documentation:

MAX7219 Datasheet

Note that even if pins are arranged in a different way, pin-out remains the same of the 8×8 LED matrix.

In this demo we are going to use Code-B decode to write with ease some number on our 8 digit 7-segment display.

In the demo shown in the video above we set up MAX7219 as normal operation mode, Code-B decode mode for each digit, scanning the whole display with the maximum continue reading...

STM32, ChibiOS and a 8×8 LED Matrix

STM32, ChibiOS and 8x8 LED Matrix

The MAX7219 is a compact, serial input/parallel output common-cathode display driver. Included on-chip there are a BCD code-B decoder, the multiplex scan circuitry, segment and digit drivers, and an 8×8 static RAM that stores each digit. Only one external resistor is required to set the segments current.

This chip is often used to drive 7-segment display having up to 8 digits or up to 64 individual LEDs. It is not unusual find this chip in DIY kits to be mounted on a small PCBs like that used in this article (See Fig. 1).

This chip could be found in different packages continue reading...

A Radio Frequency transceiver library: nRF24L01 and ChibiOS/RT

A Radio Frequency transceiver library nRF24L01 and ChibiOS/RT

The nRF24L01 is one of the most popular RF transceiver as it is very cheap and it could be found already configured on small PCBs with needed passive components. This means that only a MCU is needed to design a radio system with the nRF24L01.

The nRF24L01 is a highly integrated, ultra low power 2Mbps RF transceiver IC for the 2.4GHz ISM band. It provides an hardware protocol accelerator, the Enhanced ShockBurst, enabling the implementation of advanced and robust wireless connectivity with low cost MCUs.

By this article we want to provide a full library for nRF24L01 continue reading...

ChibiCube hardware explained

ChibiCube hardware explained

By this article, we will show schematic of ChibiCube in order to understand how it works and hot it has been designed.

As mentioned in the previous article, ChibiCube addresses all its LEDs through the combination of anode and cathode signals. Each floor of the cube is configured as common anode, while the various cathode signals are separately connected to the outputs of the Shift Register. Setting the anode voltage to a value equal or greater than the high logical threshold of our SR, for the same principle illustrated in the tutorial Meeting SPI, we can address single continue reading...

STM32F3 discovery and MEMS

STM32F3 discovery and MEMS

Reading Giovanni Di Sirio’s tweet announcing the release of ChibiOS/RT 3.0.0 preview, the reaction was enthusiasm. So I dusted off my first love, the STM32F3 discovery, to give a try to this new version of the Lizard. A few hours later took shape the demo we are going to discuss in this article.

We will show how to alternately read the data from the two MEMS mounted on the discovery and made some LED games according to read data.

Before starting, we link the “must-read” documentation for optimal use of the micro-controller:

STM32F303VC Reference Manual STM32F303VC continue reading...