I put together a project roundup for the tin can R2D2:
Some notes on the schematic:
- I don’t use the Propeller “directly” but use the Propeller QuickStart board. The schematic below is soldered on perf-board and then attached as a shield to the QuickStart.
- Fritzing offered a XBee schematic which I used for the BTBee. This is OK since they are PIN compatible.
- If you connect the speaker like in the schematic, you will get noisy ugly sound.
- If you don’t use blue LEDs which are OK with 3.3V, you will need resistors too.
Finally I got around hacking a basic Android App to control my tin can robots. To quickly get a result, I used Processings Android mode and the Ketai library for the Bluetooth stuff. Regarding the effort needed for the results, they turned out pretty well.
The App has the following features so far:
- Device Discovery
- Device Selection
- Control Panel which could be switched between right- and left-hand mode
- Adapt to devices screen size
As usual, the sources could be found on
the projects github account.
Ok, the hardware for both robots (black R2D2 and pink R2KT) is done. Also a first version of the software is loaded on the Parallax Propeller inside the two bots. In the video below you could see them driving (remote controlled from smartphone/tablet).
The tin can based R2D2 robot driving around, remote controlled through tablet using Bluetooth:
The sound in the video is pretty poor. But what you here so far is a typical R2D2 beep-beep on start-up (or when you request it by remote command), an other beep when a new command was received, some sad “ohhhh” noise when you stop the robot. Also to keep the robot happy you need to drive it (the LEDs then smile). If you break, a sad LED face is shown …
And by the way: the little speaker will soon also get it’s housing.
Today I think I 3D printed my first real useful thing. This “thing” sits on the bottom border of our windows and helps keeping them pack (against cold air). Unfortunately I don’t know the name of this thing, so I decided to call it the “window thing”. One of our windows was missing the “window thing”, so I decided to rip off one from an other window an copy it with a caliper and OpenScad. It worked pretty well so far (I need to print an other one in white, but pink fillament was already loaded, and I was to lazy for change) …
All parts are printed! Now everything is ready for a first assembly.
But first the electronic components need some wiring:
The full BOM for the electronics looks like so:
- 1 x Parallax Propeller QuickStart Board
- 2 x gear motor
- 2 x wheels for gear motor
- 1 x Pololu 3.3V Step-Up/Down regulator to supply the Propeller MCU
- 1 x TB6612FNG dual motor controller
- 1 x BTBee SSP module
- 1 x Maxbotix ultrasonic range finder (not mounted yet)
- 1 x Speaker I found in my parts bin (not mounted yet)
- 1 x LiPo battery 7.2V, 450mA for the Propeller MCU
- 1 x LiPo battery 7.2V, 950mA for the motors
- 1 x dual switch to turn MCU and motor power on/off
So lets assemble all the abovce stuff like shown in the next figure:
We get as a result a tin can on wheels:
Which looks very very close like the initial model:
Finally the inlay which will hold the batteries and the Parallax Propeller.