smarthome

The board has been split up into components and you can buy each kit separately. If you already have an external 3V and 5V power supply and a prop-plug, you can get a propeller working on this board with just the propeller kit. See the bottom of the page for notes regarding building the board all at once rather than in stages.

Solder in the power supply components. Connect a DC power supply (tip positive) and check the leds light up and that 3V and 5V are available. The board has sockets for several types of regulators and you could, for example, use a 7805 instead of the switching regulator. However, as you add more peripheral components such as a keyboard and a mouse, you will find that linear regulators will get very hot and need a large heatsink. Switching regulators do not need a heatsink.







Install the sockets, the chips and the support components. You can program this now with the Prop Plug, available separately from parallax. Alternatively, see the next step for what I consider a better solution that does not use the prop plug.





Install the sockets and support components. The max232 gives you two serial ports and also allows the propeller to be programmed with an inexpensive USB to serial adapter (included in the kit). This solution works out cheaper than using the prop plug, plus you can then talk to other boards or devices using the serial ports. There is a little jumper that selects whether you use the second serial port or the mouse.





The SD card is installed next. Solder the socket first before soldering the resistor array. You may need a solder sucker to remove any shorts between pins and/or the pins and the metal case. Check carefully under a bright light.





External memory allows you to run retro computer emulations, as well as access more code space for programming in C. Install the sockets, then the bypass capacitors and then the chips. Note that the latch chips are 74HC374 – don’t get them mixed with latches for the LCD display which are 74HCT374.





Some software, such as KyeDOS and the CPM emulation are able to display text on a 20x4LCD display. This is useful for portable applications where you don’t have a TV or VGA display. When making the cable, make sure the bump on the header socket is facing the same way. Use a vice to squeeze the cable in, do both ends, and then add the strain relief part last. To build the LCD display adaptor, first solder the 16 way sil header into the back of the LCD display. Then solder the box header onto the little adaptor board. Put a solder bridge across where it says LED on the board. Then solder the adaptor board onto the LCD display. Alternatively, you can just solder the 16 wires onto the LCD display as they end up in the right order after coming out of the header.



The parallel port adds 8 generic inputs and 8 generic outputs. No software has been written for this, though it will end up being only a few lines of Spin.



It is possible to build a board about three times faster by doing parts in groups. In general, start with the lowest parts first and then work up. I start with the SD card socket first, then do the resistors. Then I put all the sockets in, put a flat board on top of the sockets and flip the whole thing over. Then solder all the sockets at the same time. Then do all the bypass capacitors. Then I do the power supply and test it, then add all the other passives, and finally put the chips in the sockets.