www.steeman.be

This page describes the construction and operation of a device for testing rocket motors. It allows the recording of the thrust generated by the motor during a static test. The recorded data is then analyzed using an Excel spreadsheet.
This load cell amplifier is a little different from the other designs usually found on the internet. […]

To connect a PIC16F877A to my computer using a serial link, I needed a MAX232 level converter to convert between RS-232 and TTL signal levels. This post describes the schematic diagram and the board. The schematic diagram and the board layout are included in Eagle format.

The flight computer I am developing for my next rocket uses an atmospheric pressure sensor to calculate the flight altitude. I chose to use a Motorola MPX4100 sensor, since it is readily available through Conrad.be. It outputs a voltage proportional to the pressure; 0,3 V at 20 kPa and 4,9 V at 105 kPa.

The MPX4100A sensor is an SMD part (SOP case), so I needed a breakout board to be able to breadboard it. Below are the circuit diagram and the PCB layout in Eagle format.

I have recently started using Eagle to make my electronics projects, and i works so great that I finally got round to making a few boards I need very often. One of them was a power supply that plugs into the power rails of the bread board I use for prototyping my circuit.

The power supply can be fed from a wall wart, and supplies 5V and 12V to the breadboard’s power rails. It uses a pair of 7805 and 7812 IC’s for regulation.

I have incorporated wireless remote control in my rocket launch box, using ’s kits K8059 (transmitter) and K8057 (receiver). Obviously I would like to get as much separation as possible from the rocket as it is launched (and potentially explodes). The K8059 kit has a standard open field range of 30m, which ideally would have to be increased to 200m. This modification describes the changes that have to be made to the transmitter to increase its range.

Although the Kenwood TS-50 transceiver doesn’t have a serial interface, it can be interfaced to the computer for CAT (computer aided tuning) control using Kenwood accessories. The problem is that Kenwood charges almost 200€ for its CAT solution (your mileage may vary). You’ll need to buy both the IF-10D and the IF-232 unit to interface your TS-50. I figured these two units should be easy to homebrew.

One of the first things I homebrewed when I became a ham radio operator was a BayCom packet modem. This serial modem is intended for 1200baud AFSK use, and gave me many hours of pleasure while on the 2m packet network. It is fairly easy to build, if you can get your hands on the TCM3105 chip…

I own a Palm m100 organizer. It is cheap, and it helps to keep things that before floated around my head, organized. The m100 only has 2MB of RAM memory, which means it is always out of memory, especially when loading GPS maps or web site caches.
It can be upgraded to 8MB by replacing the […]

This little gizmo allows you to control your computer using any infrared remote control. I use it to control WinAmp with my stereo’s remote. Featuring a key learning mode, it will respond to commands sent by any IR remote control.

I have built and tested Jens Madsen’s PIC Programmer 2 (PP2). It programs the following versions of the PIC: PIC12C5XX, 12C67X, 24CXX, 16C55X, 16C61, 16C62X, 16C71, 16C71X, 16C8X, 16F8X (and also ISO-CARD’s with ASF). If you make an adapter socket, it can also be used to program other chips (but I haven’t tested this).