Serial comms problem

Thread Starter

Joined Nov 27, 2013
Hi to all from new member ( Tony ). I built an accelerometer to measure athletic performance. Sensors send a signal to a reed relay, a stopwatch is activated by the reed. The stopwatch sends the collected data to a usb port, the data is saved as a text file. The problem is that the bridge between the stopwatch and usb port is not robust enough in performance.
I tried to measure the acceleration of gravity, taking a split time every 20 cm, the watch put out garbage and I have been unable to recover the bridge So what I am after is a microcontroller solution, which one should I buy ?, keeping in mind I am getting on in years, limited programming experience.
Adafruit ARDX has been suggested, comment and suggestion welcome.
kindest regards, Tony


Joined Oct 2, 2009
We're here to help you as best as we can but I cannot figure out heads from tails what you are saying. You said more than a dozen things that all seem totally disconnected.

accelerometer - what accelerometer? Model number?

to measure athletic performance - what athletic performance?

Sensors - what sensors?

send signal - what signal?

to a reed relay - why?

a stopwatch - what kind of stopwatch? Model number?

is activated by the reed - how?

stopwatch sends the collected data - what collected data?

to a USB port - how does it do this?

bridge - what is a bridge?

not robust enough - what do you mean?

measure the acceleration of gravity - how do you do this?

split time?

every 20cm?


unable to recover the bridge?

You sure the garbage did not get washed away with the bridge?

Sorry, couldn't help it.

Thread Starter

Joined Nov 27, 2013
Model 1 ( my own design ). Measure Leg Power, measure potential, measure current ability. The sensors are Tiny Eye retroreflective devices that send a 12 volt signal ( can vary )> The reed relay sends a dry signal. The stopwatch is an ultrak 499. Reed is activated by the 12 volt signal. The collected data is the time delay between the last reading and the latest reading. The usb bridge is a UART that interfaces the watch to the computer, converts serial data to parallel format. Not robust enough means I am unable to reset the bridge. To measure the gravity acceleration is complex. Readings are taken every 20 centimeters. Garbage is unexpected data that makes no sense at all. Recover bridge was previously explained. Anyhow thanks for the comment.