Fail Sauce

It’s said that a chain is only as strong as its weakest link. Today, we found our weak link.

LunOrediggers was the 10th pick over all to compete, however we ended up going 4th since there were less then 10 ten with entries that were competing.

We passed inspection, weighing in at just over 68kg1. We received our briefing on our allotted five minutes of setup time and then went to work. Like a well oiled machine, we were ready and set with time to spare.

The judges counted down to power on: 5, 4, 3, 2, 1…power on.

Now this is the interesting part. The initialization sequence takes some time to complete. So even after power is applied, there isn’t any movement for a few seconds. However, the seconds soon changed into minutes. The judges reported that we were drawing no current, which was not a good sign.

After five minutes, we finally called it. Testing confirmed that the proper power was present at the connector. The judges reconnected the power cable to rover and powered it back on just to make sure. A few seconds later, things starting moving.

In somewhat of a confused panic, the judges quickly cut power. The issue had been that while we had inserted the plug into our connector, we hadn’t twisted it to lock it. This was simply because we weren’t familiar with the plug, which was a competition defined and provided part.

A temporary reprieve was issued as the judges went off to discus things.

Sometime later, they came back and decided they owned some of the responsibility between the mating of our technology and theirs. Thus, we were allowed to restart and run!

Round two began well enough. The rover powered up and began it’s initialization cycle. The sensor turret on the top moved around and then, nothing. Well not actually nothing, the sensor turret just kept performing its sweep. But the rover didn’t move. After a few minutes, we called it quits again; this time for real.

And that brings us back to the weakest link. What went wrong? Well, we haven’t had a formal diagnostic, but it seems to be a programming issue. The rover was positioned in a corner of the sandbox, with its front facing the corner. The IR sensors were close enough to the wall that they were being triggered before the rover even moved. Due to the way our error handling algorithm works, this caused the rover to continuously skip to the next command in the sequence, which left us standing still.

There is some good news though. Tomorrow, we’ll be testing again in a demonstration program. This will allow us to vet some of our other systems. There will be no rules for this demo, so we should be able to perform a complete cycle.

I’ll have some more updates and pictures tomorrow. However, more sleep is needed at this particular moment in time.

1 The maximum weight allowed was 70kg

(cross posted from http://csmnerds.com/2008/08/02/fail-sauce/)