- on Microcontrollers
- Published in issue 12/2010 on page 0
Special: Embedded Guide 2010
Free 32-page supplement covering microcontroller hardware, software, programming and applications
Beaker from the Muppet Show can be built as an interactive puppet and his presence and responses (sort of) enjoyed for all they’re worth. The project is sketched only on these pages and really intended to add a light-hearted note to this December 2010 Embedded Guide. But make no mistake, Embedded Beaker! involves programming a microcontroller and juggling MP3 files, hence is a full blown embedded project.
LED Board on ATM18
Following on from “Build a Scrolling LED Message Board in One Day” , here in one page (or almost) is how to display a 64 × 32 pixel .bmp image on the aforesaid board. No need for a 32-bit microcontroller for that — our trusty ATM18 module has everything we need for this.
USB TO RS485 / RS232 Converter
The converter described here requires only two chips and a handful of passive parts. The core of the circuit consists of an FT232RL IC from FTDI. The IC includes everything needed to create an RS232 port on a PC that doesn’t have one.
Alongside USB, the Ethernet interface is a favourite when it comes to connecting computers to other devices. The Lantronix XPortPro device does the job quite well, besides adding an ultra-compact Linux based 32-bit mini server with many protocols supported. It’s also claimed to be The World’s Smallest Linux Networking Server. The discerning Elektor reader however will want to “switch stuff at home” hence rejoice at … I/O lines!
Using Minimod18 to Control up to 256 Servo Motors
Cheap radio-controlled (R/C) cars usually have only a single servo motor, just for the steering. In small model aircraft, you typically find two (steering and climb/descend), four is already quite a lot. So who might need to control up to 256 servos?
Easy Sceptre Programming with Oberon-07
Astrobe is an integrated development system running on Windows which incorporates an Oberon-07 compiler and linker with a powerful multi-window editor and a set of library modules. You can use it to develop applications for the NXP LPC2xxx ARM7 family, which includes the LPC2148 microcontroller used in the Scepter prototyping system. This article describes the structure of an Oberon-07 application and some of the low-level features of Oberon-07 used when programming the Elektor Sceptre hardware directly.
PIC-based Lighting Controller with Triacs
The objective of this design project is to generate lighting effects for works of art produced by students and displayed in an exhibition. This involves six 12-volt, 50-watt colored halogen lamps that are rhythmically switched on and off in varying combinations according to a ‘sound-to-light’ scenario in order to achieve artistic effects from the interplay of color, light and shadow.
A Graphics Display for the Sceptre
Here's how to link the Elektor Sceptre 32-bit fast prototyping platform to the colour graphics display for the Nokia 6100 phone (132 × 132 pixel square 4096-colour display with an effective area of around 30 × 30 mm). And the icing on the cake: you can buy ready-made PCBs with this display already fitted.
Modular LED Message Board
The circuit described in thbis article only comprises 64 LEDs and has been designed as the basic building-block of a panel that can be extended as much as you want, in height and width.So each of the building-blocks making up the message board comprises only 64 LEDs. The various blocks are physically juxtaposed to build up the message board.
An over-air low-battery warning system for remote controlled models.
One Pixel Eye
In this article we show how to make a simple ‘1-pixel camera’ using an LDR and an Arduino. Two pieces of software, one for the Arduino and the other for the PC, are used to control everything.
Speed Controller for Small DC Moters
Inspiration for this design came from the need to drive a Lego model using a small electric motor. The application required the motor speed to be adjustable and capable of maintaining a constant speed under varying load conditions at low speed. The neat solution given here uses an ATtiny44 micro to measure the motor’s back-EMF and control a motor driver stage.
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- Magazine December 2010
- MC9S08SH32CWL, programmed
- ATtiny44-20PU, programmed
- PCB, bare | USB TO RS485 / RS232 Converter (100372-1)
- PCB, bare | Ground Receiver (100611-1)
- PCB, bare | XPort(Pro)-to-Breadboard Interface (100475-1)
USB TO RS485 / RS232 ConverterResistors
R1,R2,R3.R5 = 470Ohm
R4 = 33kOhm
R6 = 120Ohm
C1,C2 = 10µF 63V radial
C3,C4,C5,C6,C7 = 100nF ceramic
C8 = 10nF ceramic
L1 = 100µH choke, axial
D1,D4 = LED, green, 3mm
D2,D3 = 1N5819
IC1 = FT232RL (FTDI)
IC2 = LTC1535 (Linear Technology)
S1 = slide switch, SPDT, right Angle, e.g. C&K type OS102011MA1QN1
Tr1 = transformer, Murata type 78253/55C, ratio 1:1.31, 1.5kV isolation
Jp1 = 2-way pinheader, lead pitch 0.1 inch, with jumper
K1 = USB receptacle, Type B, right-angled
K2 = RJ45 socket, PCB mount, with integrated LEDs, shielded, e.g. Amphenol RJHSE-5381
PCB # 100372-1
Case, ABS, black, dim. 23.62x51.32x65.54 mm (0.93"x2.02"x2.58"), e.g. Serpac CH-8BK
Resistors (all SMD)
R1–R12 = 10kOhm
Capacitors (all SMD)
C1,C2 = 10µF 16V electrolytic
C3 = 100nF ceramic
C4,C5 = 10nF ceramic
IC1 = LM1117, 3.3V positive voltage regulator (National Semiconductor)
T1–T6 = BSS138 (ON Semiconductor)
S1 = pushbutton, PCB mount, 6mm footprint
K2 = XPP100300S-01R XportPro module (Lantronix), Mouser # 515-XPP100300S-01R
K1,K3 = 5-pin SIL pinheader, 0.1 inch lead pitch
PCB, # 100475