microboy

My raspberry pi zero powered mini computer (3d print files, code, product lists)

Parts

Joystick - Sparkfun COM-09426

Display - 1.3" 240x240 LCD TFT SPI Display (ST7789 Driver) no chip select pin (GND,VCC,SCL,SDA,RES,DC,BLK)

Analog to Digital converter - Adafruit ADS1015 12-bit I2C

Battery - LP603450 LiPoly 3.7V 1000mAh TG15

Battery Charge / Voltage regulator / Transformer board - Adafruit PowerBoost 500 Charger TPS61090 DC Boost (Not strong enough to power pi4 or CM4)

Small Dip Switch (unknown)

9 Momentary Tactile PCB Push Buttons 6mm x 6mm

Raspberry Pi Zero W

Wiring

RPi BOARD Pin #1 (3.3V) -> Display VCC
       		        -> Joystick VCC (Pin 4)
                        -> ADS1015 VCC

RPi BOARD Pin #2 (5V)  -> PowerBoost 5V

RPi BOARD Pin #6 (GND) -> Display GND
                       -> Joystick GND (Pin 2)
		       -> ADS1015 GND
		       -> PowerBoost GND
                       -> Small Switch Right
                       -> Button 1 Right
                       -> Button 2 Right
                       -> Button 3 Right
                       -> Button 4 Right
                       -> Button 5 Right
                       -> Button 6 Right
                       -> Button 7 Right
                       -> Button 8 Right
                       -> Button 9 Right


RPi BOARD Pin #3 (SDA) -> ADS1015 SDA
RPi BOARD Pin #5 (SCL) -> ADS1015 SCL


RPi BOARD Pin #23 (SCLK) -> Display SCL
RPi BOARD Pin #19 (MOSI) -> Display SDA
RPi BOARD Pin #15 -> Display RES
RPi BOARD Pin #11 -> Display DC
Rpi BOARD Pin #13 -> Display BLK


RPi BOARD Pin #36 -> Button 1 Left
RPi BOARD Pin #22 -> Button 2 Left
RPi BOARD Pin #18 -> Button 3 Left
RPi BOARD Pin #16 -> Button 4 Left
RPi BOARD Pin #37 -> Button 5 Left
RPi BOARD Pin #29 -> Button 6 Left
RPi BOARD Pin #31 -> Button 7 Left
RPi BOARD Pin #40 (PCM_DOUT) -> Button 8 Left
RPi BOARD Pin #38 (PCM_DIN) -> Button 9 Left

ADS1015 A0 -> Joystick X/Y (Pin 1)
ADS1015 A1 -> Joystick X/Y (Pin 3)

PowerBoost EN -> Small Switch Left

Software

Run in the console of your raspberry pi:

sudo apt-get install cmake
cd ~
git clone https://github.com/juj/fbcp-ili9341.git
cd fbcp-ili9341

Then run sudo nano display.h and paste in

#define DISPLAY_SPI_DRIVE_SETTINGS (1 | BCM2835_SPI0_CS_CPOL | BCM2835_SPI0_CS_CPHA)

under the line

#define DISPLAY_SPI_DRIVE_SETTINGS (0)

Then continue with

mkdir build
cd build

Then make sure the SPI interface is turned off either in raspi-config or through sudo nano /boot/config.txt and making sure the line dtparam=spi=off is there (not sure if this is a necessary step)

If you have previously run 'cmake' and would like a fresh start do this:

cd fbcp-ili9341/build
rm -r *

Then run the command below changing your wire numbers (if you're using different wiring) for -DGPIO_TFT_DATA_CONTROL=17 -DGPIO_TFT_RESET_PIN=22 -DGPIO_TFT_BACKLIGHT=27 to the BCM pins from this site https://pinout.xyz/pinout/pin13_gpio27

cmake -DST7789VW=ON -DGPIO_TFT_DATA_CONTROL=17 -DGPIO_TFT_RESET_PIN=22 -DGPIO_TFT_BACKLIGHT=27 -DSTATISTICS=0 -DSPI_BUS_CLOCK_DIVISOR=40 -DUSE_DMA_TRANSFERS=OFF -DDISPLAY_ROTATE_180_DEGREES=ON ..

The DMA transfers argument increases the framerate and decreases CPU usage, should be used when possible (disabled because it didn't work for me) DSPI_BUS_CLOCK_DIVISOR should be a minimal even number (start out at something safe like 40, then decrease for better FPS until you notice glitches)

Finally run

make -j
sudo ./fbcp-ili9341

And if your display is like mine (advertised as ST7789 but ended up working with ST7789VW, no cs pin) it might work

For autorun on startup put this line before exit 0 in your sudo nano /etc/rc.local

sudo /home/pi/fbcp-ili9341/build/fbcp-ili9341 &

These lines are in my sudo nano /boot/config.txt file:

hdmi_group=2
hdmi_mode=87
hdmi_cvt=640 640 60 1 0 0 0
hdmi_force_hotplug=1

Make sure that all references to dtoverlay=vc4-fkms-v3d are removed/commented out with # although I'm not sure if necessary

64 bit fbcp-ili9341

To get fbcp-ili9341 working on a rpi 4 running a 64 bit operating system, you can replace the relevant steps above with the following

git clone --branch rpi2w-64bit-port https://github.com/zxfishhack/fbcp-ili9341.git

(uses a fork of fbcp-ili9341 with 64 bit compatability)

cmake -DST7789VW=ON -DGPIO_TFT_DATA_CONTROL=17 -DGPIO_TFT_RESET_PIN=22 -DGPIO_TFT_BACKLIGHT=27 -DSTATISTICS=0 -DSPI_BUS_CLOCK_DIVISOR=6 -DUSE_DMA_TRANSFERS=ON -DDISPLAY_ROTATE_180_DEGREES=ON -DAARCH64=YES ..

Note the difference of -DUSE_DMA_TRANSFERS=ON, -DAARCH64=YES and -DSPI_BUS_CLOCK_DIVISOR=6. DMA transfers increases the framerate and decreases CPU usage, should be used when possible. The DAARCH64 parameter enables some of the changes in the rpi2w-64bit-port branch of zxfishhack's fork of fbcp-ili9341. DSPI_BUS_CLOCK_DIVISOR should be a minimal even number (start out at something safe like 40, then decrease for better FPS until you notice glitches)

Extra info

• Avoid using this display, there is very little compatability for the version of the 240x240 small ST7789 display without a CS pin.
• fbcp-ili9341 doesn't work on 64 bit operating systems yet
• fbcp-ili9341 puts the screen to sleep after a while of keyboard inactivity, give a keyboard input after starting it if you are getting a black screen
• The ADC python library is depreciated and the wrong version gets installed if you use pip, you can clone it here, usage guide here
• The crontab syntax for starting fbcp-ili9341 on boot is putting @reboot root /home/pi/fbcp-ili9341/build/fbcp-ili9341 in /etc/crontab
• Neither the Adafruit PowerBoost 500, nor a lipo battery of this size are strong enough to power a RPi 4 or CM4
• On some operating systems, fbcp-ili9341 won't build and will give the error selected processor lacks an FPU unless you remove the flags -mfloat-abi=hard and -mhard-float from somewhere in display.h
• The original Pi Zero W (used here) is too slow for decent internet browsing
• pyautogui's mouse movement is too slow on the Pi Zero W and causes noticeable stutter, use mouse instead