[Scott] as well as his friends were having some fun with their handheld transmitters someday when they chose it was time to develop some add-on hardware that might transmit as well as get place data. They set their sights on a set of Audio frequency shift Keying units that might each encoded as well as decipher place from the counterpart.

The develop got off to an simple start, centering around an Arduino board with a GPS module for catching accurate place data. next it was time to execute AFSK. On the transmitting side this was done by bit banging the output pins. After a look at the resulting signals on an oscilloscope the team was able to tune the firmware for a quite tight 1200 as well as 2200 Hz output. however difficulty was brewing on the decoding side of the equation.

The very first decoding attempt utilized the FreqMeasure library written by [Paul Stoffregen]. After no success they transferred to a hardware service in the type of the XR-2211 FSK Demodulator chip. It ought to have been simple, feed it the signals as well as checked out the digital output pins to catch the preferred data. This is the point at which you requirement to click the job link at the top to soak in all of the gory details. long story short, a noisy power rail was triggering sporadic performance of this chip. By the time this problem was found rate of interest had waned as well as the job was ditched as a failure. was there a quick repair that might have salvaged it such as adding a filtering circuit for that chip? let us understand exactly how you would get this back on track by leaving a comment below.

[Thanks Lewin]

Fail of the Week is a Hackaday column which runs every Wednesday. Help keep the fun rolling by composing about your past failures and sending us a link to the story — or sending in links to stop working compose ups you discover in your Web travels.