Monthly Archives: February 2015

LPC812 on a 20MHz External Crystal

Posted on February 25, 2015 by Jim Eli

Because the NXP LPC800 clock options and the setup are somewhat confusing, I thought I would post this example. Here is my LPC812 dev board running on a 20MHz external crystal. The frequency counter is reading the clockout pin which … Continue reading →

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LPC810 Breakout Board

Posted on February 22, 2015 by Jim Eli

This basic Arm Cortex-M0+ NXP LPC810 breakout board features a FTDI programming header, USB (mini-B) connector for power only, a LM117-3.3v voltage regulator, power LED, ISP and Reset buttons and a standard 2×5-pin 0.05″ SWD debug connector. All pins are … Continue reading →

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LPC812 Switch Matrix

Posted on February 13, 2015 by Jim Eli

One unique feature of the LPC8xx µC is the ability to swap pin functions. Want an UART TX on pin #10 and RX on #2? No problem. You can assign the pin functions via the Switch Matrix. This allows great … Continue reading →

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NXP LPC812 Clocks and Timers

Posted on February 10, 2015 by Jim Eli

Oscillators and Clocks The System Oscillator, not to be confused with the System Clock, can be fed by an external source (XTAL pins or CLKIN pin) or from the 12MHz Internal Oscillator. The external sources are limited to a maximum … Continue reading →

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ARM NXP LPC 812 (SysTick) IRQ Blnk

Posted on February 10, 2015 by Jim Eli

SysTick IRQ Blink Program:

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An ARM Up

Posted on February 5, 2015 by Jim Eli

On a recent project I needed a µC in a SOIC-20 package to fill a spot on a self-designed PCB. The project started with an ATtiny4313, but the software quickly outgrew the limited 4K flash program memory. I upgraded to … Continue reading →

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Converting a Float to a Char Array

Posted on February 5, 2015 by Jim Eli

Surprisingly, this question pops up often. While the technique used here is not really a conversion, it does allow access to the individual byte values of a float variable by constructing a union. A union is a data structure that … Continue reading →

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