LCD Gauge Update #3: 35 Data Items on 16 Pages!

MotorvateDIY

I am using a $8 ESP-32 micro controller to read the CAN bus, read the Bluetooth data, and drive the LCD display. It is quite the powerhouse!!

Two of the initial design goals was to be affordable and instant start up.

Down the road, I will be looking at using a pi as that will make it easy to drive a larger display. For now, I am focusing on a small (easier to place on the dash) display.

The most difficult and time consuming part of this project has been reverse engineering the CAN bus on multiple Nissan/Infiniti vehicles (like 370, G37, M56, Q50, etc) This is the only way to know if the gauges will work, or what to change in the code so they do work.

MotorvateDIY

Hey BULL, it was nice to chat yesterday.
Thanks for the offer to send me some pics of the disassembled 370 cluster. That will allow me to see inside the cluster without buying one. (for now!)

redondoaveb

All correct except water temp instead of oil temp. All standalone

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Fast Intentions "Stage Seb" twin turbo #098- Specialty Z/Tial-Xonarotor/CJM/Ecutek/HKS/KW/SPL/Hotchkis/Rohana/Toyo
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DPz34

Really enjoying seeing your progress on this project! Just to clarify, engine oil pressure is NOT on the CAN bus, right? Just a low oil pressure switch. Which aftermarket oil pressure sensor are you using that can send data to the bluetooth sensor server?

MotorvateDIY

I'm glad you have been following the progress. It has evolved into much more than I expected when I first started on it just over a year ago.

Correct, engine oil pressure is not on the CAN bus.

I am using a 150 PSI Honeywell PX3 pressure sensor for oil pressure and a 100 PSI PX3 for fuel pressure.

The Bluetooth sensor server will work with any 5v, 3 wire pressure sensor. They typically output 0.5 volts at 0 psi and 4.5 volts at the max rated pressure.
It does the analog to digital conversion, applies the scale and offset, then sends the data out via Bluetooth.

SLOPOS

Very familiar with that platform, granted when I was using them they were mostly used for WiFi gpio to control relays and the like, but not much else. Im guessing then you're using i2c for the screen output which wouldn't even require going to a pi as there are plenty of larger i2c screens available and the resolution and refresh rates seem to be adequate. More and more impressed with this project the more I learn about it, thanks for sharing!

MotorvateDIY

I think you meant SPI, not I2C... I2C is too slow for a full colour display.

A 320 x 240 display has 76,800 pixels, and each pixel has 16 bits (RGB565) of colour information, for a total of 1,226,800 pixels or 153,600 bytes per LCD screen/page.

The LCD controller I use supports a max SPI clock of 40 Mhz resulting in taking 0.180 seconds to draw each page. By only "drawing" the parts of the screen that change, the display updates around 30 times per second.

To make the best use of all clock cycles, I use a RTOS (real time operating system) which allows pre-emptive multitasking. This allows me to run multiple tasks at the same time.

The tasks I have set up are: reading the CAN bus, receiving Bluetooth data, and drawing the display. They all run independently and at full speed. Nice!

Also, since the ESP32 has 2 cores, core 0 is dedicated to handling all Bluetooth communications, and core 1 handles reading the CAN bus and rendering the display.

Anyways, I'm glad to share the details...

SLOPOS

Oh, derp! I was thinking esp8266 which didn't have spi capabilities *facepalm* - kinda the little brother of the esp32. I do think I have some 32s laying around from a weather station project I was working on but never finished. Can't wait to see the full published doc - if you need any 370 guinea pigs, feel free to drop be a line.

MotorvateDIY

Thanks for the offer, I will keep that in mind.
Since I am in the Toronto area, I will be testing in this area first

MotorvateDIY

Here is an overview of our Bluetooth Sensor Server.
This provides an easy way to convert any wired pressure/temperatures sensors to Bluetooth for our LCD gauges / mini-dash.
-AND-
This means you don't need to figure out how to get a wire from the engine bay, through the fire wall and into the interior of the car.
​​​​​​​https://youtu.be/U_kH3K_C2AE

redondoaveb

It's coming along great Frank. Have you decided on what size screen you're going to use? There are a few of us that would like to mount it in the existing cubby location and don't want it to be too small

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Fast Intentions "Stage Seb" twin turbo #098- Specialty Z/Tial-Xonarotor/CJM/Ecutek/HKS/KW/SPL/Hotchkis/Rohana/Toyo
700+whp

MotorvateDIY

Thanks!
Tell me what size you would like and I will see what is available and potentially acquire a few for testing.

redondoaveb

Let me do a quick survey and I'll get back to you. Thanks

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Fast Intentions "Stage Seb" twin turbo #098- Specialty Z/Tial-Xonarotor/CJM/Ecutek/HKS/KW/SPL/Hotchkis/Rohana/Toyo
700+whp

redondoaveb

Hey Frank, I think somewhere around 4" x 6" would work out really nice. You could set up a screen with just 2 gauges per screen or multiple gauges per screen (like Ecutek dashboard) can't you? For example, oil pressure and water temp. If so, it would be nice if those could be enlarged to a little under 3" diameter

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Fast Intentions "Stage Seb" twin turbo #098- Specialty Z/Tial-Xonarotor/CJM/Ecutek/HKS/KW/SPL/Hotchkis/Rohana/Toyo
700+whp

MotorvateDIY

Thank your for doing this!
I will investigate what my options are in that size.