There is no question that steering wheel mounted controls are super convenient. Reaching all the way over to the dashboard to change a radio station is so 1990’s. An ever-increasing percentage of new cars are coming equipped with steering wheel controls for the stereo, however, you’ll lose the button control if you change out the stock head unit to something a little higher in quality. Sure, there may be an adapter readily available for your car/stereo combination, but there also may not be. [Ronnied] took the DIY road and made his own adapter.
The first obstacle for [Ronnied] was to figure out the wiring on the steering wheel controls. After some poking around he found that there were only two wires used for all of the control buttons, each button only changing the resistance between the two wires. The button states could easily be read by using an Arduino’s analog input. A Pro Mini model was chosen for its small size as it could be housed in the radio compartment of the dash.
The next step was getting the Arduino to control the aftermarket head unit. [Ronnied] did some research regarding JVC’s Stalk digital control interface but came to the conclusion that it would be easier to direct wiring the Arduino outputs to the appropriate spot on the head unit’s circuit board. To do this the button for each function that would also be represented on the steering wheel was traced out to find a common point on the circuit board. Jumper wires soldered to the circuit board simply allow the Arduino to emulate button pushes. To ensure that the head unit buttons still work in conjunction with the steering wheel buttons, the Arduino would have to keep the pins as inputs until a steering wheel button was pushed, the pin changed to an output, the signal sent and the pin changed back to an input. This feature was easily created in the Arduino sketch.
Video below.




The project featured in this post is 
[Tom] told us that the team is currently redesigning their hardware. The next generation prototype board with more protection can be seen in the far right of the top photo. He also mentioned that they’re shooting for 5 digits of accuracy, placing them on par with many bench scopes. We’re skeptical to say the least about 5 digits, but the team is definitely putting their all into this product. We’ll wait until the Kickstarter backers start getting their final devices to see if Voltset is everything it’s cracked up to be.
The kiln is built from slightly blemished pallet rack shelving that [Tim] cut to suit his needs. He skinned it with 1/2″ insulation boards sealed with aluminium tape and plans to add sheet metal to protect the insulation.