Building a better bit-bang UART – picoUART

Ralph Doncaster writes, ” The screen shot above is from picoUART running on an ATtiny13, at a baud rate of 230.4kbps. The new UART has several improvements over my old code. To understand the improvements, it helps to understand how an asynchronous serial TTL UART works first. Most embedded systems use 81N communication, which means […]

App note: I/O emulated UART baud rate calibration

Software/bitbang method of baud rate calibration for micro without built-in UART, App note from Holtek. Link here (PDF) Not every HOLTEK MCU contains a Universal Asynchronous Receiver/Transmitter function, otherwise known as a UART. If this function is required, it can be emulated using software. However, the software accuracy will change according to the system frequency […]

Hacking a UART where there never was before

Thanks to Andrew for sharing – check out the full post on their blog, MOAM Industries. As part of a prototype developed 12 months ago I was tasked with reading measurements from a blood pressure cuff [sphygmomanometer] in real time. Not surprisingly there are no consumer level devices that have a serial interface because what […]

One wire control of HD44780 LCDs

Does the minimum 6 pins needed to control an LCD give your little microcontroller a sad? In the forum we’re discussing low pin-count control methods for common HD44780 parallel displays. This one uses is a simple serial UART adapter similar to our USB and Serial LCD backpack: Here’s a reasonably economical 1-pin Serial interface solution. […]

App note: Full-duplex software UART for LPC111x and LPC13xx

Here is an app note with source code describing how to implement a full-duplex software UART interface on LPC111x and LPC13xx microcontrollers. However, some applications require more UARTs than are available on the device. While the addition of an external stand-alone UART IC could be used in some of these situations, software based UARTs result […]

App note: Using UART Auto-Baud detection on dsPIC30 digital signal processors

Here is a app note from Microchip describing how to implement the Auto-Baud detection for UART operation on dsPIC30 digital signal processors. This function is useful when the oscillator of the dsPIC is unknown and/or the baud rate is unknown. All current dsPIC30F devices have a UART peripheral with Auto Baud capability. The signal on […]

Simple USB to UART adapter that works with 3.3V and 5V UART signals

The serial UART is a common interface used by many chips and devices. Ginpb designed a USB-to-UART adapter that works with 3.3V and 5V UART signals. The device is based around the FTDI FT232BL USB-to-UART IC with an added 3.3V power supply. The different interface levels are selected by an on-board jumper. Via the forum.

Save to a microSD cards with simple serial protocol

This is a UART driven microSD module that supports cards with up to 2 GB of storage. It stores data using the FAT16 file system, so any computer can read and write files to the cards too. It’s controlled with simple serial commands from a microcontroller. Most micro-controllers have small and limited on-chip memory. For […]

Implementation of UART transmitter in Verilog HDL for Spartan3 FPGA

If you’re experimenting with FPGAs its helpful to know how various common tasks are coded. Here is an article by M. Yasir explaining how to code a UART transmitter in a Spartan 3 FPGA. The tutorial uses the Verilog hardware definition language.

NEW PRODUCT: MCP2200 USB to Serial breakout board

The MCP2200 is a new USB to serial converter chip from Microchip. Our MCP2200 breakout board brings all the pins to bread board friendly headers. USB CDC virtual serial port interface Secondary HID configuration interface Up to 8 additional IO 256bytes user EEPROM TX/RX indicator LEDs All pins to bread-board friendly header Open source (CC-0) […]

Bus Pirate: Chip demonstrations

Here’s a comprehensive list of Bus Pirate chip demonstrations. It includes Ian’s old demonstrations from Hack a Day, and the most recent demos from Dangerous Prototypes. Tutorials are arranged by Bus Pirate hardware version. Bus Pirate v2&v3 Firmware v0g new feature demonstration PCF8563 real time clock calendar (I2C) ShiftBrite with A6281 3 channel LED driver […]