LEAP#394 Arduino 8051 Programmer

I’ve been meaning to dive a bit deeper into Intel MCS-51/8051 devices and programming ever since I built a Electronic Clock Kit powered by an AT89C2051.

Reading the AT89C2051 datasheet, its seems programming is actually a quite straight-forward process - the only complication being the need for a 12V programming voltage in addition to standard logic high of ~5V.

So while I could go out and buy a programmer, I found the idea of building (more...)

LEAP#393 Dickson Charge Pump

The Dickson Charge Pump is a neat trick for multiplying an input voltage. It is basically a capacitor bucket-brigade, with diodes for flow control, and a switching signal to make it go. It is not the most efficient voltage booster, and cannot drive very high currents, but may be a convenient solution depending on the application.

The version I’ve implemented here runs on an Arduino with a 62kHz PWM signal and generates a zener-regulated 12V (more...)

LEAP#392 BoldportClub Whiteboard

The BoldportClub project #22 whiteboard is a neat little “breadboard enhancer”, featuring variable and coin-cell power supplies and prototyping areas. As always, all notes, schematics and code are in the Little Electronics & Arduino Projects repo on GitHub

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Here’s a simple demonstration using the 4 LEDs on the shroud as outputs for a 4-stage CD4060 ripple counter:

Also included is a sheet of StickerCAD icons. I used them on my laptop case - including a (more...)

LEAP#391 Packaging the mV Meter

A while back I breadboarded an ATmega328-based millivolt meter based on a design by Scullcom Hobby Electronics. It uses an LTC2400 ADC and LT1019 voltage reference, and has some nice display modes on a 16x2 LCD.

It’s a nice design so I decided to go the whole hog and fab a PCB at OSHpark, but this time using EasyEDA for the schematic capture and board design. Althoughit’s PCB design tools are relatively primative, it (more...)

LEAP#389 Two-Stage Amp Design

Reviewing techniques for two-stage CE amplifier design. My calcs are a bit off (under-estimated gain), but I got a workable Class A amplifier out of it! As always, all notes, schematics and code are in the Little Electronics & Arduino Projects repo on GitHub hero_image

LEAP#387 GPS Modules

This is the first time I’ve played around with a GPS module, so it was an interesting dive into NEMA standards. But at the end of the day, the TinyGPSPlus library makes it a piece of cake to get GPS readings. I log these to serial and display the main facts on an LCD. As always, all notes, schematics and code are in the Little Electronics & Arduino Projects repo on GitHub hero_image

LEAP#386 The Blue Pill

Popularly known as the Blue Pill, the STM32F103C8T6 Minimum System Development Board seems like an excellent gateway drug for getting into ARM Cortex-M3 development.

This is particularly true as it is possible to program it with the familar Arduino IDE.

It is my first look at one of these boards, so I have simple expectations - follow along some of the tutorials on the web/youtube and at least get a simple program running on (more...)

LEAP#385 BolportClub Widlar Blinky

The µA723 voltage regulator is a classic from 1967, and was celebrated in the Boldport Club “Widlar” (Project #21). It is a bit boring to just regulate voltage, but since the µA723 contains an error amplifier and voltage reference … yes, it is possible to make an oscillator instead. My version of the Widlar glows an orange LED…

As always, all notes, schematics and code are in the Little Electronics & Arduino Projects repo on (more...)

LEAP#379 AS3935 Lightning Sensor

I first heard about the AMS AS3935 Franklin Lightning Sensor in Arduino for Ham Radio. They are available as modules with built-in tuned antenna, but are relatively expensive/rare. I finally got my hands on one to experiment with.

Since we have between 171 and 186 lightning days on average a year here in Singapore, with each square kilometer being struck up to 16 times annually, I’m expecting to have some fun with this.

Here’s (more...)

LEAP#378 BJT Phase Splitter

Simple unity-gain phase splitter in a little breadboard-compatible package. It uses a common-emmiter amplifier with a gain of -1.

As always, all notes, schematics and code are in the Little Electronics & Arduino Projects repo on GitHub hero_image