R_e_c_u_r 3.5 inch SPI screen compatibility

I am interested in purchasing a used display / lot of displays for use with a r_e_c_u_r as prices for this project seem to keep increasing. Is it necessary to use the
Waveshare 3.5 inch SPI display listed in the build manual? I am most interested in the MHS 3.5 inch SPI display, which has a higher refresh rate (50hz) that would theoretically allow for more useful mirroring than the Waveshare display. Both are dependent on drivers, but maybe there is some hardcoding in r_e_c_u_r that I’m not aware of.

Anyone have any experience using alternative SPI displays with r_e_c_u_r? From what I understand, I need a non-touch-enabled screen in order to still have access to a second output via CV. Can’t find much more documentation than that.

1 Like

I personally am not too sure but I can say that I’ve used cheaper Waveshare clones in the past that work fine. I suppose the only way to know is to try but if it uses another driver it could be as simple as changing the overlay in config.txt

Thanks, I am optimistic. Once everything arrives from fleabay I will give it a shot. Realistically I would use a splitter + second monitor set-up most of the time, but having a proper on-device preview would be nice for travel/low-scale gigs.

2 Likes

even though i recommend the waveshare displays on the docs i actually have never bought one directly from them - iv always used cheaper clones from aliexpress… whcih use the same drivers…

im not sure if the one you have linked will be compatible out of the box - depends if different drivers are needed, but im sure it will be possible to get it working if you are prepared to install / set it up first…

one thing to note however is that i doubt it will result in higher refresh rate of mirroring - the low mirroring refresh rate is not a limitation of the screen (you can play videos quite smoothly on these screens) its more to do with how the framebuffer outputs are configured on the pi.

in short: when you connect the 3.5inch display and enable the drivers it outputs the rpi desktop onto framebuffer1 - which is where the interface is displayed when running recur… however the video output is still written to framebuffer0 - which is what is sent over hdmi/cvbs - the mirroring working using raspi2fb to copy everything on fb0 and dump onto fb1 - this is the bottle neck on refresh rate…

im not too what you mean by this. but using the waveshare clone screen i have enabled the touch screen features before… and connected the x & y position of this to effect parameters similar to kaoss pad style … and this works ! (although i stil prefer accessing effects via midi control)

the screen does need to connect over gpio - as you need to keep the hmdi output for video-out… so you cant use hdmi displays for recur

Thank you for your detailed reply and all of your work on r_e_c_u_r and everything else. Not sure exactly where my misunderstanding regarding touchscreens came from. Case closed, then: I will get a cheapo screen! Thank you.