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  View original topic: Megasquirt and Raspberry Pi Dash
av8shunmeckaneck Fri Dec 18, 2020 1:11 am

Thought some other Megasquirt users might find this little writeup about my dash useful. The intent is not to promote a bunch of stuff but to let you know what worked for me after some experimenting with different components.

I put a Subaru EJ205 with Megasquirt in my 181 and I'm using a 7" touchscreen with a Raspberry Pi mounted to the back as a dash.

For the monitor, I broke the first one and got a replacement of the same one. The touch function never worked correctly, or at all. The next monitor developed a line of "static" up the middle after a month or so.

My current display, and why I am writing this, is the best one yet. I found this one during Black Friday. It actually fits the Pi 4 correctly on the back and comes more than enough cables to mount everything in a neat package. It comes with ribbon cables that are exactly the right length so you dont need bulky HDMI and USB cables.
Here is a snipit of the ad for the one got from Amazon.




It also includes built in speakers on the back that I havent bothered with yet (maybe never).

The main reason I got this display is because of the screen buttons on the back. None of the monitors I've used or seen on Amazon had screen control buttons, more specifically dimming. The dash, even with a non-flashy dash selected, can be a little bright at night.

Right away I ordered a 4-way hat switch to control 'Menu' 'Up' 'Down' 'Exit'. The buttons are 4 pin momentary switches. The outboard row are all common grounds to eachother. The 2 pins on each switch on the inner row are common to each other on the switch (hope that makes sense).

The switch works awesome, Its time to figure out where to mount it now.

If your're interested in the rest of how I did the Pi dash is in my thread in the 181 forum. Look up Thingaru.

Thanks for watching.

modok Fri Dec 18, 2020 1:27 am

your post isn't showing up because of the link to amazon

av8shunmeckaneck wrote: Thought some other Megasquirt users might find this little writeup about my dash useful. The intent is not to promote a bunch of stuff but to let you know what worked for me after some experimenting with different components.

I put a Subaru EJ205 with Megasquirt in my 181 and I'm using a 7" touchscreen with a Raspberry Pi mounted to the back as a dash.

For the monitor, I broke the first one and got a replacement of the same one. The touch function never worked correctly, or at all. The next monitor developed a line of "static" up the middle after a month or so.
(amazon link here) My current display[/url], and why I am writing this, is the best one yet. I found this one during Black Friday. It actually fits the Pi 4 correctly on the back and comes more than enough cables to mount everything in a neat package. It comes with ribbon cables that are exactly the right length so you dont need bulky HDMI and USB cables.


It also includes built in speakers on the back that I havent bothered with yet (maybe never).

Now, for the main reason I got this newest display, the screen buttons on the back. None of the monitors I've used or seen on Amazon had screen control buttons, more specifically dimming. The dash, even with a non-flashy dash selected, can be a little bright at night.

Right away I ordered a 4-way hat switch to control 'Menu' 'Up' 'Down' 'Exit'. The buttons are 4 pin momentary switches. The outboard row are all common grounds to eachother. The 2 pins on each switch on the inner row are common to each other on the switch (hope that makes sense).

The switch works awesome, Its time to figure out where to mount it now.

If your're interested in the rest of how I did the Pi dash is in my thread in the 181 forum. Look up Thingaru.

Thanks for watching.

av8shunmeckaneck Fri Dec 18, 2020 1:35 am

Thanks Modok. I couldn't figure out why the whole thing was blank.

It would be nice if there was a pop-up message or something to let me know.

Oh well, I'll read the rules next time.

Guess I'll fix it now and add in some images that I forgot.

gprudenciop Fri Dec 18, 2020 11:10 am

another way of doing it is to get a 80 dollar tablet from walmart that runs windows, and a mini keyboard and dc to dc converter. $110 total.

Max Welton Fri Dec 18, 2020 1:48 pm

Android tablet running Shadow Dash

https://www.youtube.com/watch?v=cS3hwncBv_w&feature=youtu.be

https://www.youtube.com/watch?v=1nmcrYU_K-Q&feature=youtu.be

Max

Krochus Fri Dec 18, 2020 8:04 pm

I considered raspberry for my Microsquirt truck and just couldn’t get over the shutdown issue for a nearly daily driven vehicle

I use a $20 app called MSdroid and a free ex work tablet. I setup tasker to auto launch the app on usb connection which happens when I flip a usb switch. Easy peasy

I also have access to virtually all tuning functions through msdroid so I seldom get my laptop out anymore




buguy Fri Dec 18, 2020 9:05 pm

I'd like to do something like that. I have a very similar tablet that i got free when i bought my last phone. How is that in the sun? Can you see ok in your truck?

Max Welton Fri Dec 18, 2020 9:09 pm

I got some anti-glare film ... at office depot or staples I think.

Max

av8shunmeckaneck Sat Dec 19, 2020 2:41 am

I have the Pi running all the time. The display is powered off a seperate usb power supply that is turned off with the key. The display came with a micro JST to USB lead for the touch function. I had to de-pin the power because the Pi would power the display through the connector.

I thought about a tablet based dash with MSdroid or Shadow Dash. I figured the Pi would be a little easier to tweak on the hardware side. You can get these awesome little OLED displays and design custom individual analog looking gauges.


I forgot about anti-glare film. FWIW, at home I have a wall picture that came with anti-glare 'glass' (acrylic most likely). It appears frosted but when placed up against the picture in the frame you cant even tell its there. <---As I typed that outloud I realised you can't but it infront of a touchscreen..duh.

Still waiting for an official version of Google Drive 'Backup and Sync' for linux. Pi-Dash has it setup so that your log files are sync'ed a shared Google Drive folder. That way you can edit the tune on a seperate computer, save it the drive folder and load it to Tunerstudio.

I considered using my older Surface Pro 3 and make a center console similar to a Tesla. But I didnt feel comfortable leaving an expensive tablet in the car. Plus, its sort of big.

Krochus Sat Dec 19, 2020 6:41 am

Just turning the display off is an interesting approach.


What is the battery drain like from just the cpu in the background?

I know if I leave my tablet in communication with the usb/rs232 converter it drains the tablet battery down in a few hours.

Max Welton Sat Dec 19, 2020 8:59 am

av8shunmeckaneck wrote: I forgot about anti-glare film. FWIW, at home I have a wall picture that came with anti-glare 'glass' (acrylic most likely). It appears frosted but when placed up against the picture in the frame you cant even tell its there. <---As I typed that outloud I realised you can't but it infront of a touchscreen..duh. The stuff I got was designed for touch-screens. Came in 8x11 sheets.
av8shunmeckaneck wrote: Still waiting for an official version of Google Drive 'Backup and Sync' for linux. Pi-Dash has it setup so that your log files are sync'ed a shared Google Drive folder. That way you can edit the tune on a seperate computer, save it the drive folder and load it to Tunerstudio.
The logging features are one of the more useful features of MS. For a while I logged every minute of run-time. I was daily-driving the car at the time so that was 100s of files. My own personal black-box. 8)

Max

av8shunmeckaneck Sat Dec 19, 2020 6:59 pm

Krochus wrote: Just turning the display off is an interesting approach.


What is the battery drain like from just the cpu in the background?

I know if I leave my tablet in communication with the usb/rs232 converter it drains the tablet battery down in a few hours.

Kills the car battery after 4 or 5 days of sitting. I'd have to look but there are published numbers of what Pi4 draws in standby. I need to look into using the GPIO pins to trigger it to sleep when I turn off the car. That would get me a few more days.



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