Lightning does strike twice

Just a quick update this time. Got a lot on at the moment!

If you were around for the last Pi Wars you may remember I fried a Pi for the first time ever whilst mucking about with relays for the skittle ball release mechanism. It was sad. We had a minute’s silence. RIP RPi.

Weeeeell, it would appear I doggone went and did it again. Nooooooo!! This time it was whilst trying to hook up the Adafruit servo board (which I’ve used successfully several times in the past.)

There was smoke this time too. Proper thick, acrid, really not good smoke type of smoke. Rapidly followed by lots of frantic wire pulling.

Was undoubtedly a classic ID10T error. A quick aide memoir for myself and others:

9v > 5v > 3v3

This is important. It goes wrong quickly if you mix them up. Very quickly.

I was in all honesty surprised when the Pi actually booted up again. Sadly though, a quick check of the i2c deelybob (that’s a technical term I think) revealed that all was not well…

snafu

I’m not sure therefore if it’s the i2c driver on the Pi that’s gone, or whether its the servo board. In reality, I’ve not had time to check, I swapped out the Pi for a fresh one and have limited myself to using the hardware PWM on GPIO 18 of the Pi. I’m only running one servo that holds an arm to hold the ball in place (hopefully) for the golf and skittles events.

I had another moment earlier this week when, on reviewing the challenges on the piwars.org site that I realised that there had been a small, but rather flippin important change to the skittles challenge – someone put a turn in the course! I’d not seen the important ‘competitors must collect the ball and then…’ bit. The wonderful @GeekyTim ‘fessed up on Twitter when challenged and admitted that it was indeed he who had added a little something extra. This should make it a lot more interesting and requires some thought in actually controlling the ball to even get it as far as going in the direction of the skittles.

I’ve still got a long way to go, have been manically designing and printing a wild and wacky range of attachments to serve in the array of challenges. More of these next time. The bot is being assembled and reassembled repeatedly as I test, fit and retest different configurations. I’ve got most of the manual challenges sorted now and am working on the challenges that require some form of autonomy. I *may* have made these an awful lot more difficult than they reasonably should be due to a critical design decision I took very early on in the process. I’ll let you know.

So – onward and PiWar’d. Ermm…. did I say there’s only two weeks to go? Gotta dash – I’ll catch up with you all later.

Until next time…

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