Button Play

For my scouts groep I'm designing a Button-Play. The goal is to press the button as fast as possible. The one who presses fastest is selected, by his light turning on.

This is very usefull for like a quiz game. Attached is the eagle schematic of the boardlayout seen below. The shown pcb layout fits directly into an mushroom shape security button, shown on the right.

Multiple buttons can be added by daisychaining them. I've choosen standard UTP with 8 wires for the interconnection, for one because they are easily found, and secondly they have multiple wires in the same cable.

Temperature Sensor TMP100

For the mini2440 I've choosen a TI TMP100 I2C temperatur sensor. This sensor can measure in 0.5 degree steps, and is support by the lm75 kernel driver.

The only problem with the sensor is that the LM75 module does not autodetect the chip, and one has to force detection by echo'ing "tmp100

to new_device in /sys/bus/i2c/devices//new_device

Here is a picture of the sensor board. It will lateron piggyback on the daughterboard.

Promised Pictures

Here are some pictures I've made from the housing.

First the front. I'm still thinking on covering the screws on the front with some sticker.

Then the inside picture. Which shows the mini2440. At the moment it is build on the bottom of the housing, which is not very pratical if I'm going to put it up on the wall, then I want the LAN cable to come from the back instead of external. This will change next, after I've finished the d

aughter-board.

Last is a bottom view, where as said now the LAN, Comport, Power and Audio ports of the mini are made accessible.

mini2440

About a year ago I bought a friendly arm mini2440 development board with a 7 inch display.

The goal of my project is to create a home-automation system. Starting with replacing the central heating regulation with the mini2440. For this I will need to add an IO output switch to the board, which will turn on the heating system, and a temperatur sensor to measure the main temperatur in the house.

But first things first. The mini2440 came without a housing. So I bought a standard housing from RS Components..

RS stocknummer 509-5003, shown on the left. It is a bit larged for the mini2440, but then again leaves enough room for additions.

I'll try and post some foto's of the end results later.