Menticol
Active Member
Hello everyone!
I'm working on repurposing a Chinese motorcycle dashboard for a racing simulator. I’ve successfully generated the 12V PWM signals to control the RPM and speedometer indicators as needed.
Now, I want to work on the fuel gauge. The gauge reads as "full" when its cable is shorted to ground and "empty" when it’s open. By precisely varying the resistance to ground, I aim to display intermediate levels such as 20%, 40%, and 80%.
The schematic below (apologies for the low quality) shows my approach. Each test point input is connected to an ESP32 micro-controller output, controlled programmatically. Only one transistor must be conducting at any given time.
Unfortunately, this circuit currently produces only random values on the gauge, and I’m not sure why. I’m aware this issue could be resolved with relays instead of transistors, but since I plan to use the same approach for the gearbox indicator, I would prefer to avoid the clicking noise and the wear and tear associated with relays on this application.
Any input (no pun intended) will be very appreciated
I'm working on repurposing a Chinese motorcycle dashboard for a racing simulator. I’ve successfully generated the 12V PWM signals to control the RPM and speedometer indicators as needed.
Now, I want to work on the fuel gauge. The gauge reads as "full" when its cable is shorted to ground and "empty" when it’s open. By precisely varying the resistance to ground, I aim to display intermediate levels such as 20%, 40%, and 80%.
The schematic below (apologies for the low quality) shows my approach. Each test point input is connected to an ESP32 micro-controller output, controlled programmatically. Only one transistor must be conducting at any given time.
Unfortunately, this circuit currently produces only random values on the gauge, and I’m not sure why. I’m aware this issue could be resolved with relays instead of transistors, but since I plan to use the same approach for the gearbox indicator, I would prefer to avoid the clicking noise and the wear and tear associated with relays on this application.
Any input (no pun intended) will be very appreciated
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