This project is a 7 segment LED display module that can be driven using SPI protocol, so it needs only 3 pins of your mcu to drive 4 x LED displays. It’s based on MAX7219 LED display driver.
Seven segment LED displays are very popular for displaying numeric information because they are very attractive and readable from a far distance and wider viewing angle.
The downside is they are resource-hungry. For example, it requires 12 I/O pins of a MCU to drive a 4-digit seven segment display using a standard time-division multiplexing technique.
Here I present a serial seven segment LED display module that can be used with any MCU using a 3-wire SPI interface. This particular display has four digits (0.40 size) and two colon segments (to support time display) display.
Serial 4-digit seven segment LED display - [Link]
Microchip’s ENC28J60 is a 28-pin, 10BASE-T stand alone Ethernet Controller with on board MAC & PHY, 8 Kbytes of Buffer RAM and an SPI serial interface.
It takes just few components to get the ENC28J60 up and running and connected to a host microprocessor or microcontroller which support the standard SPI interface. Below I have designed a small ENC28J60 module. The ENC28J60 has a operating voltageof 3.3V, but the board is designed to run with 5V supply voltage, i.e. inculdes a 3.3 voltage regulator for the power supply and a 74ACT125 used as level shifter for the control lines. So it can be directly connected to any 5V microcontroller system. Optionally, an I2C EEPROM can be assembled on the board which can be used e.g. to store websites if the board is used in an embedded webserver environment.
ENC28J60 Ethernet Module - [Link]
DM&P has been producing low-power, x86-based Vortex processors for the embedded market for over ten years. Now in a nod to the Arduino market they have released the 86Duino Zero, a low-cost Arduino Leonardo sized board powered by their latest 300 MHz SoC Vortex86EX Processor.
This is a fully static 32-bit x86 processor board compatible with Windows OS, Linux and most other popular 32-bit RTOS. It integrates a PCIE bus, DDR3, ROM controller, xISA, I2C, SPI, IPC (Internal Peripheral Controllers with DMA and interrupt timer/counter included). The 86Duino Zero’s ports include USB 2.0 host and device coastline ports, a 10/100 Ethernet port and a microSD slot on the bottom of the board. The Zero’s baseboard also provides a 7-12V power jack, a reset button and a PCIe expansion connector.
The Zero supplies 14 digital I/O pins, half of which can provide 32-bit resolution PWM outputs and six 11-bit analog input pins. Each standard I/O pin supplies 16 mA while the 3.3 V pins can supply up to 400 mA. Like the Intel Galileo development board announced several weeks ago the 86Duino Zero marries Intel architecture to the Arduino platform. Its $39 price tag makes it an attractive proposition. [via]
The 86Duino Zero Runs Linux on x86 - [Link]
Embedded Lab’s new development board for PIC12F series microcontrollers:
The 12F series of PIC microcontrollers are handy little 8-pin devices designed for small embedded applications that do not require too many I/O resources, and where small size is advantageous. These applications include a wide range of everyday products such as hair dryers, electric toothbrushes, rice cookers, vacuum cleaners, coffee makers, and blenders. Despite their small size, the PIC12F series microcontrollers offer many advanced features including wide operating voltage, internal programmable oscillator, 4 channels of 10-bit ADC, on-board EEPROM memory, on-chip voltage reference, multiple communication peripherals (UART, SPI, and I2C), PWM, and more. Today we are introducing a new development board (rapidPIC-08 V1.0) for easy and rapid prototyping of standalone applications using PIC12F microcontrollers.
Rapid development board for PIC12F series microcontrollers - [Link]
Bertho shared his NoLoop galvanic isolator:
I had a problem some time ago with a nasty ground-loop and that cost me the USB port on my old laptop. It took me a while to realize what had happened and it was a generic problem we all run into more often than we think. Time to solve this particular problem once and for all and make generic isolation for Serial and SPI ports.
NoLoop galvanic isolator - [Link]
The MAX21000 is a low power, low noise, 3-axis angular rate sensor that delivers unprecedented accuracy and sensitivity over temperature and time. It operates with a supply voltage as low as 1.71V for minimum power consumption. It includes a sensing element and an IC interface that provides the measured angular rate to the external world through a digital interface (I2C/SPI). The IC has a full scale of ±31.25/±62.50/±125/±250/ ±500/±1k/±2k degrees per second (dps) and measures rates with a finely tunable user-selectable bandwidth.
MAX21000 – Ultra-Accurate, Low Power, 3-Axis Digital Output Gyroscope - [Link]
Here is a small collection of circuits that provide an interface to sensor transducers including pressure, temperature, and others.
This circuit provides a highly integrated analog sensor signal conditioner targeted for automotive applications. The device provides amplification, calibration, and temperature compensation. Output is digital. Read the rest of this entry »
Seven segment LED displays are known to be resource and power hungry. But because they are visually so charming and readable from a far viewing distance and at a much wider viewing angle as compared to any other electronic displays, they are still hugely popular. The required number of I/O pins to drive the LED segments can be reduced significantly by using an additional dedicated hardware. For example, the MAXIM’s MAX7219 device allows you to interface 8 pieces of seven segment LED modules using only 3 I/O pins of Arduino or any other microcontroller.
High-voltage seven segment LED display driver with SPI interface - [Link]
ArthurTC @ instructables.com writes:
In this instructible we will learn how we can hook up an LCD based on the HD44780 chipset to the SPI bus and drive it with only 3 wires for less than $1. Although I will focus on the HD44780 alphanumeric display in this tutorial, the same principle will work pretty much the same for any other LCD which uses an 8 bit parallel data bus, and it can be very easily adapted to suit displays with 16 bit data buses.
The HD44780 (and compatible) based alphanumeric displays are usually available in 16×2 (2 lines consisting of 16 characters) and 20×4 configurations, but can be found in many more forms. The most ‘complicated’ display would be a 40×4 display, this sort of display is special as it has 2 HD44780 controllers, one for the upper two row and one for the bottom two rows. Some graphic LCDs have two controllers as well.
3-Wire SPI HD47780 LCD for less than 1 dollar - [Link]
techshopdude @ instructables.com writes:
There are many electronic devices that use the SPI bus, or Serial Peripheral Interface bus, for communications (e.g. various sensors, LCD displays, digital potentiometers, D/A and A/D converters, wireless transmitters and receivers, audio volume controls). The devices receive data serially from a microcontroller using a 3-wire set-up that includes a chip select signal (usually titled CS – when this signal is at logic 0, a chip recognizes it will be receiving or sending data), a clock signal for clocking the serial data into the device, and the serial data stream itself.
Using an Arduino to Control or Test an SPI electronic device - [Link]