Apparently pipers (bagpipers) often practice their playing by ‘playing’ the steering wheel while driving. This led to the idea of rigging a steering wheel cover with sensors so that you can actually play:
The sensors are decorative metal buttons from a fabric store. Each button is connected directly to a pin on an Arduino pro mini board. There are eight buttons total each placed to correspond to a hole on the bagpipe chanter:
Using the Arduino synth library that I made some years ago and a variation of the “Pseudo Capacitive Touch” interface mentioned in an earlier post I was able to make a reasonable sounding bagpipe chanter. To map each key to It’s corresponding pitch I needed to find the actual frequencies of each note on the chanter. It turns out that the notes are a bit off compared to standard MIDI notes. Here are a table from this page thanks to Ewan Macpherson:
| Note name | Ratio to low A |
Cents from low A |
Closest ET note |
ET cents | Deviation from ET |
Freq for A = 466 Hz |
Freq for A = 475 Hz |
| high A | 2:1 | 1200.0 | A | 1200 | 0.0 | 932 | 950 |
| high GM | 9:5 | 1017.6 | G | 1000 | +17.6 | 839 | 855 |
| high GJ | 16:9 | 996.1 | G | 1000 | -3.9 | 828 | 844 |
| high GH | 7:4 | 968.8 | G | 1000 | -31.2 | 816 | 831 |
| F(#) | 5:3 | 884.4 | F# | 900 | -15.6 | 777 | 792 |
| E | 3:2 | 702.0 | E | 700 | +2.0 | 699 | 713 |
| DM | 27:20 | 519.6 | D | 500 | +19.6 | 629 | 641 |
| DJ | 4:3 | 498.0 | D | 500 | -2.0 | 621 | 633 |
| C(#) | 5:4 | 386.3 | C# | 400 | -13.7 | 583 | 594 |
| B | 9:8 | 203.9 | B | 200 | +3.9 | 524 | 534 |
| low A | 1:1 | 0.0 | A | 0 | 0.0 | 466 | 475 |
| low GM | 8:9 | -203.9 | G | -200 | -3.9 | 414 | 422 |
| low GH | 7:8 | -231.2 | G | -200 | -31.2 | 408 | 416 |
Since the Arduino Synth library are capable of playing up to 4 voices simultaneously it is also possible to play 3 out of the 4 drones of the Highland bagpipe but for training purposes this is not desirable.
Here is a video of the prototype being tested:
To make an easy interface to the car stereo and get power to drive the project I bought a combined FM transmitter and phone charger:
Here is the project on the road: