Pi Claw Update Part 3 - Fixes and ToDo

To play the Pi Claw head over to http://piclaw.xyz/


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Well it's been a little while since the last claw update so here's whats been happening!

If you follow me on twitter you'll likely have seen most of this however I've tried to merge it here in order.

Painting!

The machine has been entirely re-painted with a blue and orange theme and to finish it off the T-molding have been replaced with silver.

Here's a series of tweets showing the progress. I'll have a final image soon.

Electronics

The first version of the electronics also arrived in great time from Elecrow, I assembled it up and once the painting was finished tested it and...

It didn't work, upon investigating it seems that I forgot to pull down the H-Bridges logic inputs down to ground as the Raspberry Pi's GPIO is connected via a Diode to the bridge.

To bodge this I simply put some resistors from the diodes output to ground and then all of the motors worked perfectly!

I then found the claw did not shut and upon some more investigation found that the issue was that eagle had failed to draw the airwire between the 48V input to the positive connection on the claw. This should fix it?

I then ran the test program, the claw moved over to pick something up, lowered the claw then BANG. The power had cut out to the unit by the fuse on the input of the circuit.

I used a 20V reverse diode for the flyback on the EMC. /facepalm. I disconnected everything but the power supply and went to test it but once again the fuse popped as it seems that I damaged the power supply.

About £30 Later my new Power Supply setup arrived. The original had one unit to provide 5,12,24 & 48V. However I struggled to find one of these so instead went for 3 Smaller PSUs one of 12,24 & 48V at 3A each (1A More than the original rated current). Also being newer they're much more efficient and produce less heat.

I then plugged it all back in (after also re-solding a new diode of the correct rating and transistor) and it works!

Website and how you can play!

As of this you can now* play the claw online!

I've set it up with a web interface where you can drag two sliders to select how many seconds in each direction to move and it'll perform the actions with a live stream.

You can go and play over at http://piclaw.xyz/

The stream will be up from around 10:00 to 21:00 most days for the next week or so. Varying on factors such as if it needs repair. If I'm out most of the day etc.

To-Do

There's still some tweaks I want to do varying from major to minor tweaks. These are:

  • Finish re-assembly of the front panel so the buttons can be used again to control the claw.
  • Add FAQ Page to website
  • Finish T-molding on the last window
  • Get new Decals for top & Bottom
  • Tweak user ID on website
  • Improve live stream speed
  • Design & order new PCB with bodges pre-applied.
  • Possibly change music
  • Add payout sensor

And more!


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