xunonove
Daily Driver
Ciao Amici,
This is probably sacrilege for some of you purists out there, but I am continuing work on the dashboard of my '74 with K20 conversion and decided to modernize it. I am so grateful to Rodger for documenting and posting so many details about his build, and to Bob Brown for his electrical guru-ness and offering to make a final Marshall gauge conversion for me. I declined this kind offer because I wanted to try and tackle the gauge job myself.
Instead of the "traditional" conversion cutting up the original circuit board and soldering jumper wires, I elected to go a difference route: I used a string of addressable LEDs and an Arduino to power the gauge lights.
The basic setup is that the input wires are routed to a device called an optocoupler, which takes the 10-14V signal from the various inputs (blinkers, warning lights from the Hondata, etc) and sends a steady 5V connection to the Arduino, which it needs to sense the signal.
I decided to only replace the speedometer, but left the original tachometer (I'd rather have the backwards RPM tach then matching gauges!).
The stereo is a 7 inch Android that is readily available on eBay. It's nice and narrow, so fits within a widened radio space without protruding. The signal goes to a 400W amp and then a sound bar on the parcel shelf and a subwoofer in the spare tire bay. That's a post for another day...
Back of the gauge cluster:
Front of gauge cluster in its new home:
All of the wiring fits behind the Bertone speaker grille. There are a lot of wires - every signal needs it's own positive and ground. Some of the signals to the original cluster are positive and grounded to work, others are the opposite. These go to the optocoupler.
The optocoupler then sends the signal to the Arduino.
The code is pretty straightforward. I'm not a coder, but self-taught after watching some youtube tutorials. There is a library called "FastLED" that makes programming the addressable LEDs pretty easy. You can change color, brightness, etc. I have 15 lights, but you can control hundreds if so desired. They are also RGB so you can make them any color you want.
You'll also need a couple of 12V to 5V adapters. These are the things that are inside of the car cigarette lighter phone chargers. These are also readily obtainable on ebay. One powers the Arduino, one powers the light LEDs.
I should mention that everything is obviously fused - be careful to isolate all the wires and protect against shorts, as there are a lot of wires involved in this process. Meticulous labeling is also helpful.
It all tucks behind the Bertone grille. An installation in a later car may be trickier as it doesn't have this space. I will aim to clean this up later and probably use a more permanent solution with wires soldered onto an Arduino Nano Pro Mini.
The gauge lights are nice and bright, and I can even make silly light shows if I want.
Final gauge cluster with lights:
Final outcome:
I'm happy to share my experience with this. Reach out if you have any questions, want a copy of the code, etc.
Scott
This is probably sacrilege for some of you purists out there, but I am continuing work on the dashboard of my '74 with K20 conversion and decided to modernize it. I am so grateful to Rodger for documenting and posting so many details about his build, and to Bob Brown for his electrical guru-ness and offering to make a final Marshall gauge conversion for me. I declined this kind offer because I wanted to try and tackle the gauge job myself.
Instead of the "traditional" conversion cutting up the original circuit board and soldering jumper wires, I elected to go a difference route: I used a string of addressable LEDs and an Arduino to power the gauge lights.
The basic setup is that the input wires are routed to a device called an optocoupler, which takes the 10-14V signal from the various inputs (blinkers, warning lights from the Hondata, etc) and sends a steady 5V connection to the Arduino, which it needs to sense the signal.
I decided to only replace the speedometer, but left the original tachometer (I'd rather have the backwards RPM tach then matching gauges!).
The stereo is a 7 inch Android that is readily available on eBay. It's nice and narrow, so fits within a widened radio space without protruding. The signal goes to a 400W amp and then a sound bar on the parcel shelf and a subwoofer in the spare tire bay. That's a post for another day...
Back of the gauge cluster:
Front of gauge cluster in its new home:
All of the wiring fits behind the Bertone speaker grille. There are a lot of wires - every signal needs it's own positive and ground. Some of the signals to the original cluster are positive and grounded to work, others are the opposite. These go to the optocoupler.
The optocoupler then sends the signal to the Arduino.
The code is pretty straightforward. I'm not a coder, but self-taught after watching some youtube tutorials. There is a library called "FastLED" that makes programming the addressable LEDs pretty easy. You can change color, brightness, etc. I have 15 lights, but you can control hundreds if so desired. They are also RGB so you can make them any color you want.
You'll also need a couple of 12V to 5V adapters. These are the things that are inside of the car cigarette lighter phone chargers. These are also readily obtainable on ebay. One powers the Arduino, one powers the light LEDs.
I should mention that everything is obviously fused - be careful to isolate all the wires and protect against shorts, as there are a lot of wires involved in this process. Meticulous labeling is also helpful.
It all tucks behind the Bertone grille. An installation in a later car may be trickier as it doesn't have this space. I will aim to clean this up later and probably use a more permanent solution with wires soldered onto an Arduino Nano Pro Mini.
The gauge lights are nice and bright, and I can even make silly light shows if I want.
Final gauge cluster with lights:
Final outcome:
I'm happy to share my experience with this. Reach out if you have any questions, want a copy of the code, etc.
Scott
