Prusa Touchscreen 3.5" with Raspberry Pi 4b and a Fan v4 kit by RockLava

Last crawled date: 3 years ago

The point is to use a $30 3.5” screen that runs off the DSI ribbon cable connected directly to a Raspberry Pi 4b so I don’t have to have drivers installed or modify anything on the OS. It is just plug and play and just runs right away. I also wanted to have active cooling so I have a very thin Pi Fan (comes with heat sink for 4b and 3b) and I have used the brass/copper heatsink for the 3b to have low profile with a fan sitting on top. I had to move one of the heatsinks on the board next to the fan to be able to put the fan on it. This entire assembly will sit on the table and touch it after kind of like feet so that no pressure on the top causes it to bend. Its thick enough that it should not bend anyway and I have added to the walls so it’s pretty strong.
In v2 I added a rear replacement panel with a clip in wall so the front hole is covered. You only have to reprint the rear cover with wall.
I am using a Raspberry Pi 4b 4gig and a 32gig MicroSD card. I did not include those below as I already had them. I put my pricing next to the item when I bought it below. All the accessories including the screen was $70 USD. I bought everything on amazon.
I printed it with supports only on the outside ramps that connect the LCD to the Prusa Frame, and the two-bottom touchscreen supports where there are floating squares to keep them straight. They do print ok without supports but not as clean. Like the normal Prusa LCD case, it has some supports that need to be broken out in the rear of the case where the screen clips in, and on the SD card side where the SD card sticks out.
I have two L shape cables that can connect to the pi and fit in the case and run between the screen and the Pi so you don’t have to have a cable coming out the top. Both I tested are listed below. I put this part together before putting the Pi In.
When you assemble the two parts for the screens joining the Prusa LCD with the Touchscreen, install the three screws on the Prusa panel first and tighten them. You have to push down on the emergency button to get the screw to fit in, don’t push to hard on it, just enough to get the screw started. Then install the Prusa LCD.
The touchscreen can go in two ways, A) from the bottom carefully but you need to make sure you watch the cable for the screen. This way will require removal of the SD card to install. B) This way you can keep the SD Card installed when putting it in. From the top you can put the screen in diagonally putting the bottom side in first and slowly and carefully lowering the top part turning it inside until you get it to fit like a puzzle. Don’t push hard on the screen cause you don’t want to crack it, if it doesn’t fit it might be some print or plastic stopping and you can take it out with Xacto. It is too tight depending on your print you might need to just make sure the plastic in the two corners is trim and smooth on the inside. It should be a just right tight fit so it doesn’t move around. Once you put the back on it will hold it all in place.
Put the back together and break out one section of the grill to be able to plug in the fan pins after its assembled. Put the side the says Pi Fan towards the RPi4b. It will blow toward the Pi. Then the grill goes on top with the nuts on the top outside. If you tried putting them inside, they might touch the RPi and short something. Again, I have used the brass/copper heatsink for the 3b that came with the fan to have low profile with a fan sitting on top.
Note: I have had problems with Raspberry Pi 4b power supplies saying they are 3.5 Amp that don’t work and when I put a meter on them, they are not 3.5amp. I did locate and test two models that worked but one came in a different kit. The one I listed below worked. You will know when you plug in the screen and power on the Pi 4b because you will see a little lightning bolt on the screen top left corner when there is not enough power.
Ps: I have modified so many models I don’t even know who to give credit to at this point, so thank you to everyone I stole from! I have taken things from others and combined and I’ve added to them but all of these pieces have been modified in some way except the back fan grill.
3.5” Screen =$30
OSOYOO 3.5 Inch DSI Touchscreen LCD Display for Raspberry Pi 4 B 3 Model B+ 2 | Capacitive Finger Touch screen | Plug and Play Monitor Compatible with Raspbain Ubuntu Kali RetroPie Windows 10 IOT core
by osoyoo
https://www.amazon.com/dp/B08634Y16L/ref=cm_sw_em_r_mt_dp_WJHFA0FKRMMWWKQ4H5AZ
Super Thin Pi Fan and comes with smaller heat sinks for 3b but I use for 4b = $7
GeeekPi Raspberry Pi 4 Fan, Raspberry Pi Cooling Fan 30x30x7mm DC 5V Brushless CPU Cooling Fan with 7PCS Raspberry Pi Heatsink for Raspberry Pi 4 Model B,3B+,Pi 3 & Retroflag NESPI CASE Plus (1-Pack) by GeeekPi
https://www.amazon.com/dp/B07C9C99RM/ref=cm_sw_em_r_mt_dp_PYBGAEP4C9S8XGS0YAGF
Screws = $8
100pcs M3 x 8mm 12.9 Grade Alloy Steel Hex Socket Head Cap Screws Bolts,Black Oxide Finish by zw99 Store
https://www.amazon.com/dp/B07CMQ1SQH/ref=cm_sw_em_r_mt_dp_NWDP1T69PG54VHVVV1JP
Choice A: Thin Long Cable – USB-C for Power to RPi4b = $13
ADT-LINK USB 3.1 Type-C Male to USB3.1 Type-C Male Up/Down Angle 3A USB Data Sync & Charge Cable Type c Cord Connector Adapter FPC FPV Flat 10G.BPS 20cm (20CM, T2-T1)
https://www.amazon.com/dp/B08DTF5W81/ref=cm_sw_em_r_mt_dp_JC8XEBBDZ0Q2DGZ904TB
Choice B: Thin Short Cable – USB-C alternative cable for RPi4b = $13
Short Slim USBC Cable FPV Soft Ribbon FPC Cable USB Type C 90 Degree Angled to USB Type C Straight for sync and Charging (5CM)
by permanent industry
https://www.amazon.com/dp/B07LFZ5RV7/ref=cm_sw_em_r_mt_dp_AW5BSGYCWB4CHKCC367J
Better Power supply 3.5 amp verified works with screen and camera attached to RPi4b = $12
Argon ONE Raspberry Pi 4 USB Type C Cable Power Supply | 5 Feet Long | UL Listed 18 Watts 5.25 Volts 3.5 Amps USB C Cable Power Adapter
https://www.amazon.com/dp/B07TW4Q693/ref=cm_sw_em_r_mt_dp_JQ7MQYQ1D35W63HDZFWW
Connector for Extension cable from USB-C to hook the small RPi4b cable to power supply =$7
Cellularize USB C Female to Female Adapter (Black, 2 Pack) 3.1/10Gbps USB Type C Coupler Extender Extension Connector for Samsung Galaxy S8, Google Pixel, Nintendo Switch by Cellularize
https://www.amazon.com/dp/B07S292X2V/ref=cm_sw_em_r_mt_dp_F9C74YSF5FBDBSVZ8FNK