Post by Admin on Feb 3, 2014 22:56:43 GMT -5
My obsession with carputers began as a fairly simple idea. I have a 1970 Cadillac Eldorado. It doesn't have an ECM. In fact, you'd be hard pressed to find a single transistor. It also has a complete lack of gauges. Apart from fuel and speed, there are only idiot lights for temperature and oil pressure. And while I could purchase a ready-made gauge cluster, I wanted to do something a bit more...modern.
The idiot lights are driven by switches. When the temperature exceeds a threshold, the temperature switch closes and a light on the dash turns on. Similar case with oil pressure. If it gets too low, a switch closes and turns on a light.
I managed to find modern sending units with the same diameter and thread count as the original switches. These units use a 5 Volt reference voltage and return an analog range of values.
My plan is to use an Arduino Uno to convert the analog values to digital values. I learned that the Arduino has a 10-bit A/D (analog-to-digital) converter. This results in converting a voltage range of 0 - 5 volts into integers from 0 - 1,023. From there, it becomes a matter of establishing what those integers mean in Fahrenheit degrees or PSI.
All of the above turned out to be fairly simple with the exception of having to run all of the wires. My next step is to feed those values to some form of display. I can currently display them on a 2-line LCD. However, I'd like something a bit more impressive, which may require more than the Arduino alone. I may also wish to add other features such as playing MP3s or tethering my phone. Once Summer returns, I'll get back to being serious about next steps.
The idiot lights are driven by switches. When the temperature exceeds a threshold, the temperature switch closes and a light on the dash turns on. Similar case with oil pressure. If it gets too low, a switch closes and turns on a light.
I managed to find modern sending units with the same diameter and thread count as the original switches. These units use a 5 Volt reference voltage and return an analog range of values.
My plan is to use an Arduino Uno to convert the analog values to digital values. I learned that the Arduino has a 10-bit A/D (analog-to-digital) converter. This results in converting a voltage range of 0 - 5 volts into integers from 0 - 1,023. From there, it becomes a matter of establishing what those integers mean in Fahrenheit degrees or PSI.
All of the above turned out to be fairly simple with the exception of having to run all of the wires. My next step is to feed those values to some form of display. I can currently display them on a 2-line LCD. However, I'd like something a bit more impressive, which may require more than the Arduino alone. I may also wish to add other features such as playing MP3s or tethering my phone. Once Summer returns, I'll get back to being serious about next steps.