Still working on mounting everything to run the Raspberry Pi on my T-Hex robot. Yesterday I did some work to remove the network wire from the pi, by installing an Edimax USB wireless adapter( amazon.com/Edimax-EW-7811Un- … 003MTTJOY/ ) which arrived yesterday.
After I updated my WPA configuration file to look like that one, I can now connect to my Pi with wifi.
Next up, mount the Pi inside the T-Hex, where before I had a Botboarduino. I think I will do that by using one of my prototype Seeeduino Mega shield rejects that I had not populated and mount the Pi to it with small spacers and then use the mounting holes which have the correct spacing to the T-Hex…
I have updated the power connector on the T-Hex to the type I have on my LiFePo4 batteries (Quick connect red ones, where one is horizontal and the other vertical), and So I can connect it up. I have the BEC wired up, with the output 5v going to a sparkfun micro USB breakout, so can power up Raspberry Pi. Also have it going out to small plug that plugs into a small USB hub I purchased a long time ago from Radioshack. Now just need to get all of this stuff, stuffed somehow on the T-Hex. Need to check to see if I have some real short USB cables… Hopefully in the next few days will have it all self contained.
Just a small update over on my front. Since you saw in my last update mine is moving as well I figured it was time to install everything on the bot as well. Here are a couple of images of the rpi installed using hex standoffs. I had to “stack” several things due to the footprint of space being rather tight.
I haven’t done much else because I’ve been sidetracked with openCV and text to speech experiments. I figured I’d give the robot a voice.
It has the SSC-32u board on one side and the Raspberry Pi attached to the other side. I am using one of my Prototype Seeeduino Mega shields that I had fabricated earlier. I drilled a few holes in it to match the Pi’s mounting holes and then attached it with screws with some plastic spacers. I then attached it to the T-Hex using the standard Lynxmotion hole patterns.
The T-Hex is using an LifePo4 battery (hopefully the slightly higher voltage won’t hurt the 645mg servos). Also using a Castle UBEC to get 5v’s to fee into the small USB hub that is also inside, which is also feeding the Raspberry Pi. I have an XBee attached to the front of the T-Hex. This is one of their USB adapters.
Still needs some cleanup and the like, but it works.
Other things to figure out. Sound? Switch to Arc32 instead of SSC-32? This T-Hex has foot sensors, but currently no place to plug them in…
Hey Kurt I’m not sure if I told you but I’ve been playing with espeak and festival for voice feedback. It’s interesting! I have it speaking the voltage as well as other startup commands. It’s kind of funny to hear it say “Triple Tripod sixteen steps” when I’m switching gaits. Check them out when you have time.
Thanks Kåre,
The shield is simply used to have something to screw into… I thought about cutting some plastic of some type to make a hole adapter from the pi holes to the Lynxmotion standard board hole pattern, when I remembered I had several first generation unpopulated servo shields with the Lynxmotion hole pattern, so simply used one to adapt… Yep it is fun to play with. Only problem is I have several projects all calling out for time.
Kevin, May have to look into those. Which hardware supports this?
EDIT: forgot the Pi has some sound support built in. HDMI plus headphone(line level jack). I hacked up a stereo cable and put one of the same little speakers I used on some other processors and sudo aplay can play a police siren sound. So far I have not gotten the voice output to output to the device…
I need to catch up with you. I haven’t put the legs on the hex since mounting the pi. I’ve been just trying different things with the pi. Trying to understand the GPIO and all it’s capable of as well. Plus the weather has been great… I was outside and running errands all day today. I was reading your progress on my phone. I just finished mowing the yard. I’ll try and muster up some extra energy to put the legs back on tonight. How is it up north? Decent?
Well the weather is getting nicer up here in the NW today, so spent morning out walking the dogs, and maybe this afternoon will do some yard work and make juice, so I maybe slacking off
Yep, I am trying the steps in the link you mentioned and I am getting some speech now. Not sure but in the /etc/modules file it had a line with:
snd-bcm2835, but this instruction says: snd_bcm2835 so I will need to verify which one is right. Also found a typo in their test for festival in that it had -tts instead of --tts.
I am getting a barely audible sound output using just a simple speaker (like the ones on the BB2 or Botboarduino) connected directly to one channel output. So I probably need some form of small amplifier output. I think Trossen maybe has a simple breakout board for this? Edit: Took another look at their new one (trossenrobotics.com/robotgeek-buzzer) and found that it does not have any amplification, it is the same as when I simply jamb the speaker wires into a servo extension wire and then plug the servo wire in…
Coleman: Have you tried any of your products like: robotshop.com/productinfo.as … lang=en-US on your Pi? Does it work? I am not wanting ear splitting volume. Actually I often put tape over the speaker on the BB2 or Botboarduino as to quite them down…
Alan, I could wire my own, as my shields as well as the BotBorduino have a little amplification designed in. But was hoping for simple set ups like the Trossen ones that have simple amplifier built in
I am not sure if it is a proper amp, but it does have the signal going to a transistor (GP NPN AMP SOT-23), plus some other stuff like capacitors, resistors, diode.
As you mentioned I could probably figure out how to hook one up. But might be nice to simply use on that is already built.
So I wanted to give an update. I was sidetracked tonight experimenting with different leg setups trying to come up with a 4dof leg with the brackets I had. After seeing Tyberius’s Envy I settled on this leg design while I was switching back to 3dof leg. I have everything put back together now and ready to shoot another video. Sadly it’s getting late and I have jury duty tomorrow. So no late night for me. The top has to come off again for more drilling so that is why I only have four screws in the top plate per servo. Anyway here is what it looks like currently. (I have a tendency to tweak and play so it might change.) Due to the Pi and the servo power supply the battery is now relocated to on top.
I just finished mowing the yard. I’ll try and muster up some extra energy to put the legs back on tonight. How is it up north? Decent?
