A really small 32 bits computer (2013)

Elektor magazine had an article about a new 32 bits ARM cpu from NXP called the LPC800 series.

There were a couple of evaluation boards available and you could sign up if you wanted one. Alas as I entered my request, all evaluation boards were already given.

To my surprise there suddenly was a small parcel in my mailbox and upon opening I found the LPC800 evaluation board!

2013-06-27 18.19.54

The board consists of an 8 pin DIP chip with some prototyping area alongside. This tiny chip is a full blown 32 bit ARM M0 series CPU with 8k Flash memory and 1k SRAM. It has 6 selectable IO pins which can do I2C, SPI, UART (dual!), analog comparator and plain GPIO. Furthermore there are timers and all kinds of interrupts available.

Connection to a hosts computer is through a TTL level serial connection (FTDI for example) and power supply is by means of a micro USB socket.

Programming is by means of the LPCxpresso IDE and within a short time I had some results from this tiny device. But what can be done with only 6 pins of IO ? By some clever pin usage it was possible to program a two player PONG clone with composite video output (CVBS). All written in C and running on two AAA batteries drawing only a few milliamps.

The original idea was to use two analog controllers since the LPC8xx has two analog comparator inputs but after hours and hours of troubleshooting and datasheet reading it still would no work.

I mailed NXP about the problem I had with using the comparator showing my code. Well it should have worked.. I had found a fault in the chip! Proved that in the first series of the 8 pin LPC810 the comparator was not functional… As a reward I got a handful of LPC810’s of the new production batch.

The photos show the demo board I made with two Atari compatible joystick ports.



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