Before start with examples please check System Preparation
To build the project run the command:
mvn clean package
The following outputs will be created in the target directory:
jgpio-examples.jarfilelibsdirectory
Copy these files to the device with GPIO pins.
This example was prepared and tested on a Raspberry PI 5.
To make this work on other boards, you will have to modify the chip and line in the source code.
If you are working with a Raspberry 5, connect the LED with a resistor between GND and GPIO14,
as shown below:
Then run the Blink application using command:
java \
--enable-native-access=eu.softpol.lib.jgpio \
-p jgpio-examples.jar:libs \
-m eu.softpol.lib.jgpioexamples/eu.softpol.lib.jgpioexamples.Blink
The LED should blink 10 times.
This example is based on the blink, just add a button between GND and GPIO18, as shown below:
To run use command:
java \
--enable-native-access=eu.softpol.lib.jgpio \
-p jgpio-examples.jar:libs \
-m eu.softpol.lib.jgpioexamples/eu.softpol.lib.jgpioexamples.Toggle
When the button is pressed, the LED should be on.
This example lists all chips and lines, it's similar to gpiodetect and gpioinfo.
To run use command:
java \
--enable-native-access=eu.softpol.lib.jgpio \
-p jgpio-examples.jar:libs \
-m eu.softpol.lib.jgpioexamples/eu.softpol.lib.jgpioexamples.ShowAllChipsAndLines
Sample output
--------------------------------------------------------------------------------
Chip name: gpiochip0
Chip label: pinctrl-rp1
Chip lines(54):
offset name in use direction
0 ID_SDA no input
1 ID_SCL no input
2 GPIO2 no input
3 GPIO3 no input
4 GPIO4 no input
5 GPIO5 no input
6 GPIO6 no input
7 GPIO7 no input
8 GPIO8 no input
9 GPIO9 no input
10 GPIO10 no input
11 GPIO11 no input
12 GPIO12 no input
13 GPIO13 no input
14 GPIO14 no output
15 GPIO15 no input
16 GPIO16 no input
17 GPIO17 no input
18 GPIO18 no input
19 GPIO19 no input
20 GPIO20 no input
21 GPIO21 no input
22 GPIO22 no input
23 GPIO23 no input
24 GPIO24 no input
25 GPIO25 no input
26 GPIO26 no input
27 GPIO27 no input
28 PCIE_RP1_WAKE no input
29 FAN_TACH no input
30 HOST_SDA no input
31 HOST_SCL no input
32 ETH_RST_N used by "phy-reset" output
33 - no input
34 CD0_IO0_MICCLK used by "cam0_reg" output
35 CD0_IO0_MICDAT0 no input
36 RP1_PCIE_CLKREQ_N no input
37 - no input
38 CD0_SDA no input
39 CD0_SCL no input
40 CD1_SDA no input
41 CD1_SCL no input
42 USB_VBUS_EN no output
43 USB_OC_N no input
44 RP1_STAT_LED used by "PWR" output
45 FAN_PWM no input
46 CD1_IO0_MICCLK used by "cam1_reg" output
47 2712_WAKE no input
48 CD1_IO1_MICDAT1 no input
49 EN_MAX_USB_CUR no output
50 - no input
51 - no input
52 - no input
53 - no input
--------------------------------------------------------------------------------
Chip name: gpiochip10
Chip label: gpio-brcmstb@107d508500
Chip lines(32):
offset name in use direction
0 - no input
1 2712_BOOT_CS_N used by "spi10 CS0" output
2 2712_BOOT_MISO no input
3 2712_BOOT_MOSI no input
4 2712_BOOT_SCLK no input
5 - no input
6 - no input
7 - no input
8 - no input
9 - no input
10 - no input
11 - no input
12 - no input
13 - no input
14 PCIE_SDA no input
15 PCIE_SCL no input
16 - no input
17 - no input
18 - no input
19 - no input
20 PWR_GPIO used by "pwr_button" input
21 2712_G21_FS no input
22 - no input
23 - no input
24 BT_RTS no input
25 BT_CTS no input
26 BT_TXD no input
27 BT_RXD no input
28 WL_ON used by "wl_on_reg" output
29 BT_ON used by "shutdown" output
30 WIFI_SDIO_CLK no input
31 WIFI_SDIO_CMD no input
--------------------------------------------------------------------------------
Chip name: gpiochip11
Chip label: gpio-brcmstb@107d508520
Chip lines(4):
offset name in use direction
0 WIFI_SDIO_D0 no input
1 WIFI_SDIO_D1 no input
2 WIFI_SDIO_D2 no input
3 WIFI_SDIO_D3 no input
--------------------------------------------------------------------------------
Chip name: gpiochip12
Chip label: gpio-brcmstb@107d517c00
Chip lines(17):
offset name in use direction
0 RP1_SDA no input
1 RP1_SCL no input
2 RP1_RUN used by "RP1 RUN pin" output
3 SD_IOVDD_SEL used by "vdd-sd-io" output
4 SD_PWR_ON used by "sd_vcc_reg" output
5 SD_CDET_N used by "cd" input
6 SD_FLG_N no input
7 - no input
8 2712_WAKE no input
9 2712_STAT_LED used by "ACT" output
10 - no input
11 - no input
12 PMIC_INT no input
13 UART_TX_FS no input
14 UART_RX_FS no input
15 - no input
16 - no input
--------------------------------------------------------------------------------
Chip name: gpiochip13
Chip label: gpio-brcmstb@107d517c20
Chip lines(6):
offset name in use direction
0 HDMI0_SCL no input
1 HDMI0_SDA no input
2 HDMI1_SCL no input
3 HDMI1_SDA no input
4 PMIC_SCL no input
5 PMIC_SDA no input
--------------------------------------------------------------------------------
Chip name: gpiochip0
Chip label: pinctrl-rp1
Chip lines(54):
offset name in use direction
0 ID_SDA no input
1 ID_SCL no input
2 GPIO2 no input
3 GPIO3 no input
4 GPIO4 no input
5 GPIO5 no input
6 GPIO6 no input
7 GPIO7 no input
8 GPIO8 no input
9 GPIO9 no input
10 GPIO10 no input
11 GPIO11 no input
12 GPIO12 no input
13 GPIO13 no input
14 GPIO14 no output
15 GPIO15 no input
16 GPIO16 no input
17 GPIO17 no input
18 GPIO18 no input
19 GPIO19 no input
20 GPIO20 no input
21 GPIO21 no input
22 GPIO22 no input
23 GPIO23 no input
24 GPIO24 no input
25 GPIO25 no input
26 GPIO26 no input
27 GPIO27 no input
28 PCIE_RP1_WAKE no input
29 FAN_TACH no input
30 HOST_SDA no input
31 HOST_SCL no input
32 ETH_RST_N used by "phy-reset" output
33 - no input
34 CD0_IO0_MICCLK used by "cam0_reg" output
35 CD0_IO0_MICDAT0 no input
36 RP1_PCIE_CLKREQ_N no input
37 - no input
38 CD0_SDA no input
39 CD0_SCL no input
40 CD1_SDA no input
41 CD1_SCL no input
42 USB_VBUS_EN no output
43 USB_OC_N no input
44 RP1_STAT_LED used by "PWR" output
45 FAN_PWM no input
46 CD1_IO0_MICCLK used by "cam1_reg" output
47 2712_WAKE no input
48 CD1_IO1_MICDAT1 no input
49 EN_MAX_USB_CUR no output
50 - no input
51 - no input
52 - no input
53 - no input