May 2020

433 MHz Wireless Data Range Extender

This simple, solar-powered 433MHz repeater can extend the range of your keyfob transmitter where range is limited by eg trees or other obstacles. Intended for devices that transmit intermittent bursts.

Range up to 200m in open space with optimised antenna. Repeater chaining possible (with caution). PIC 16F88-based, with codes downloadable for free from the PE Online Shop (registration required).

Bridge-mode Audio Amplifier Adaptor

In need of some extreme, earth-shattering power from your audio amp? You can combine this small, easy-to-build ‘bridge-tied load’ unit with a standard stereo amplifier to easily generate 400W into a single 8R speaker, or up to 1kW or more – per channel!

It produces up to four times the existing power into a single speaker, using a stereo amp or two mono amps. Use as a standalone module or build into your audio equipment.

iCEstick (Part 2)

A field-programmable gate array (FPGA) is considerably more proficient than a microcontroller in many ways. Following last month’s review of the Lattice iCEstick and IceStudio software, this month we offer a sample of its capabilities by creating an FPGA-based VGA terminal, which generates a VGA signal similar to an early home computer, ideal for simple text displays on monitors.

Ultra-low-distortion Preamplifier with Tone Controls (Part 2)

Last month we introduced our state-of-the-art stereo preamplifier. Along with almost unmeasurable noise and distortion, it sports a remote volume control, input selection and muting, along with bass and treble instrument knows on the front panel. This month we build the input selectors and power supply.

 Please read our note in the April 2020 issue Parts List before purchasing components.

Make it with Micromite (Part 16) – Introducing the Micromite Robot Buggy

This fun and highly customisable project demonstrates an ensemble of Micromite techniques and capabilities. The MRB was inspired by the popular Zumo buggy and offers enthusiasts the chance to give their Micromite a set of wheels (or tracks anyway)!

Also in this issue:

• Techno Talk – IoT vulnerabilities and Air-gen, electricity out of thin air
• Net Work – a network-attached Freeview receiver, and problems with a Humax PVR
• Circuit Surgery – impedance measurement and Howland current sources
• PIC n’ MIX – Audio Spectrum Analyser – bandwidth expansion
• Audio Out – Building the analogue noise generator described last month, and creating a variety of appealing synthesiser circuits.
• Visual Programming with XOD –  an instant pushbutton timer
• Max’s Cool Beans – Flashing LEDs and drooling engineers

Next month:

AM/ MW/ CW Scanning HF/ VHF RF Signal Generator; Steering wheel Audio button-to-infrared Adaptor; Ultra-low-distortion Preamplifier with Tone Controls (Part 3); Micromite Robot Buggy; Visual programming with XOD.