OrangePi Lite PA19 port problems

Hello Folks,

sorry for popping up here with a technical problem first thing - but I have some trouble.

I have a circuit where an attenuator is connected to PA19. Sadly, the port seems to have a pull up which stays active even when I use wiringPi to set the port to input - in fact, even if I short the pin to low via my Keithley ammeter, it still shows up as high.

Re things which I already tried: I tried to reduce the fex file to look like this:

[product]
version = "100"
machine = "orangepi-lite"

[platform]
debug_mode = 1
eraseflag = 1
next_work = 2

[target]
boot_clock = 1008
storage_type = -1

[key_detect_en]
keyen_flag = 0

[fel_key]
fel_key_max = 7
fel_key_min = 2

[card_boot]
logical_start = 40960
sprite_work_delay = 500
sprite_err_delay = 200
sprite_gpio0 = port:PL10<1><default><default><default>
next_work = 3

[box_start_os]
used = 1
start_type = 1
irkey_used = 1
pmukey_used = 1
pmukey_num = 3
led_power = 0
led_state = 0

[boot_init_gpio]
used = 1
gpio0 = port:PL10<1><default><default><1>
gpio1 = port:PG11<1><default><default><1>

[recovery_para]
used = 1
mode = 2
recovery_key = port:PL04<0><default><default><default>

[pm_para]
standby_mode = 1

[card0_boot_para]
card_ctrl = 0
card_high_speed = 1
card_line = 4
sdc_d1 = port:PF00<2><1><2><default>
sdc_d0 = port:PF01<2><1><2><default>
sdc_clk = port:PF02<2><1><2><default>
sdc_cmd = port:PF03<2><1><2><default>
sdc_d3 = port:PF04<2><1><2><default>
sdc_d2 = port:PF05<2><1><2><default>

[card2_boot_para]
card_ctrl = 2
card_high_speed = 1
card_line = 8
sdc_cmd = port:PC06<3><1><2><default>
sdc_clk = port:PC05<3><1><2><default>
sdc_d0 = port:PC08<3><1><2><default>
sdc_d1 = port:PC09<3><1><2><default>
sdc_d2 = port:PC10<3><1><2><default>
sdc_d3 = port:PC11<3><1><2><default>
sdc_d4 = port:PC12<3><1><2><default>
sdc_d5 = port:PC13<3><1><2><default>
sdc_d6 = port:PC14<3><1><2><default>
sdc_d7 = port:PC15<3><1><2><default>
sdc_2xmode = 1
sdc_ddrmode = 1

[twi_para]
twi_port = 0
twi_scl = port:PA11<2><default><default><default>
twi_sda = port:PA12<2><default><default><default>

[uart_para]
uart_debug_port = 0
uart_debug_tx = port:PA04<2><1><default><default>
uart_debug_rx = port:PA05<2><1><default><default>

[force_uart_para]
force_uart_port = 0
force_uart_tx = port:PF02<3><1><default><default>
force_uart_rx = port:PF04<3><1><default><default>

[jtag_para]
jtag_enable = 0
jtag_ms = port:PA00<3><default><default><default>
jtag_ck = port:PA01<3><default><default><default>
jtag_do = port:PA02<3><default><default><default>
jtag_di = port:PA03<3><default><default><default>

[clock]
pll_video = 297
pll_ve = 402
pll_periph0 = 600
pll_gpu = 576
pll_periph1 = 600
pll_de = 864

[dram_para]
dram_clk = 624
dram_type = 3
dram_zq = 0x3b3bfb
dram_odt_en = 1
dram_para1 = 283377664
dram_para2 = 0
dram_mr0 = 6208
dram_mr1 = 64
dram_mr2 = 24
dram_mr3 = 2
dram_tpr0 = 0x48a192
dram_tpr1 = 0x1c2418d
dram_tpr2 = 0x76051
dram_tpr3 = 0x0
dram_tpr4 = 0x0
dram_tpr5 = 0x0
dram_tpr6 = 0x64
dram_tpr7 = 0x0
dram_tpr8 = 0x0
dram_tpr9 = 0x0
dram_tpr10 = 0x0
dram_tpr11 = 0x6aaa0000
dram_tpr12 = 0x7979
dram_tpr13 = 0x800800

[wakeup_src_para]
cpu_en = 0
cpu_freq = 48
pll_ratio = 273
dram_selfresh_en = 1
dram_freq = 36
wakeup_src0 =
wakeup_src_wl = port:PG10<4><default><default><0>
wakeup_src_bt = port:PL03<6><default><default><0>

[uart0]
uart_used = 1
uart_port = 0
uart_type = 2
uart_tx = port:PA04<2><1><default><default>
uart_rx = port:PA05<2><1><default><default>

[uart1]
uart_used = 0
uart_port = 1
uart_type = 4
uart_tx = port:PG06<2><1><default><default>
uart_rx = port:PG07<2><1><default><default>
uart_rts = port:PG08<2><1><default><default>
uart_cts = port:PG09<2><1><default><default>

[uart2]
uart_used = 0
uart_port = 2
uart_type = 4
uart_tx = port:PA00<2><1><default><default>
uart_rx = port:PA01<2><1><default><default>
uart_rts = port:PA02<2><1><default><default>
uart_cts = port:PA03<2><1><default><default>

[uart3]
uart_used = 0
uart_port = 3
uart_type = 4
uart_tx = port:PA13<3><1><default><default>
uart_rx = port:PA14<3><1><default><default>
uart_rts = port:PA15<3><1><default><default>
uart_cts = port:PA16<3><1><default><default>

[spi0]
spi_used = 0
spi_cs_bitmap = 1
spi_mosi = port:PC00<3><default><default><default>
spi_miso = port:PC01<3><default><default><default>
spi_sclk = port:PC02<3><default><default><default>
spi_cs0 = port:PC03<3><1><default><default>

[spi1]
spi_used = 0
spi_cs_bitmap = 1
spi_cs0 = port:PA13<2><1><default><default>
spi_sclk = port:PA14<2><default><default><default>
spi_mosi = port:PA15<2><default><default><default>
spi_miso = port:PA16<2><default><default><default>

[spi_devices]
spi_dev_num = 1

[spi_board0]
modalias = "spidev"
max_speed_hz = 33000000
bus_num = 0
chip_select = 0
mode = 0
full_duplex = 1
manual_cs = 0

[gpio_para]
gpio_used = 1
gpio_num = 20
gpio_pin_1 = port:PA06<1><default><default><0>
gpio_pin_2 = port:PA13<1><default><default><0>
gpio_pin_3 = port:PA14<1><default><default><0>
gpio_pin_4 = port:PA01<1><default><default><0>
gpio_pin_5 = port:PD14<1><default><default><0>
gpio_pin_6 = port:PA00<1><default><default><0>
gpio_pin_7 = port:PA03<1><default><default><0>
gpio_pin_8 = port:PC04<1><default><default><0>
gpio_pin_9 = port:PC07<1><default><default><0>
gpio_pin_10 = port:PA02<1><default><default><0>
gpio_pin_11 = port:PA21<1><default><default><0>
gpio_pin_12 = port:PA07<1><default><default><0>
gpio_pin_13 = port:PA08<1><default><default><0>
gpio_pin_14 = port:PG08<1><default><default><0>
gpio_pin_15 = port:PA09<1><default><default><0>
gpio_pin_16 = port:PA10<1><default><default><0>
gpio_pin_17 = port:PG09<1><default><default><0>
gpio_pin_18 = port:PG06<1><default><default><0>
gpio_pin_19 = port:PA19<0><0><0><0>
gpio_pin_20 = port:PG07<1><default><default><0>


[leds_para]
leds_used = 1
green_led = port:PL10<1><default><default><1>
green_led_active_low = 0
red_led = port:PA15<1><default><default><0>
red_led_active_low = 0

[ths_para]
ths_used = 1
ths_trip1_count = 6
ths_trip1_0 = 75
ths_trip1_1 = 80
ths_trip1_2 = 85
ths_trip1_3 = 90
ths_trip1_4 = 95
ths_trip1_5 = 105
ths_trip1_6 = 0
ths_trip1_7 = 0
ths_trip1_0_min = 0
ths_trip1_0_max = 1
ths_trip1_1_min = 1
ths_trip1_1_max = 2
ths_trip1_2_min = 2
ths_trip1_2_max = 3
ths_trip1_3_min = 3
ths_trip1_3_max = 4
ths_trip1_4_min = 4
ths_trip1_4_max = 5
ths_trip1_5_min = 5
ths_trip1_5_max = 7
ths_trip1_6_min = 0
ths_trip1_6_max = 0
ths_trip2_count = 1
ths_trip2_0 = 105

[cooler_table]
cooler_count = 8
cooler0 = "1200000 4 4294967295 0"
cooler1 = "912000 4 4294967295 0"
cooler2 = "768000 4 4294967295 0"
cooler3 = "648000 4 4294967295 0"
cooler4 = "480000 4 4294967295 0"
cooler5 = "480000 3 4294967295 0"
cooler6 = "480000 2 4294967295 0"
cooler7 = "480000 1 4294967295 0"

[nand0_para]
nand_support_2ch = 0
nand0_used = 0
nand0_we = port:PC00<2><default><default><default>
nand0_ale = port:PC01<2><default><default><default>
nand0_cle = port:PC02<2><default><default><default>
nand0_ce1 = port:PC03<2><default><default><default>
nand0_ce0 = port:PC04<2><default><default><default>
nand0_nre = port:PC05<2><default><default><default>
nand0_rb0 = port:PC06<2><default><default><default>
nand0_rb1 = port:PC07<2><default><default><default>
nand0_d0 = port:PC08<2><default><default><default>
nand0_d1 = port:PC09<2><default><default><default>
nand0_d2 = port:PC10<2><default><default><default>
nand0_d3 = port:PC11<2><default><default><default>
nand0_d4 = port:PC12<2><default><default><default>
nand0_d5 = port:PC13<2><default><default><default>
nand0_d6 = port:PC14<2><default><default><default>
nand0_d7 = port:PC15<2><default><default><default>
nand0_ndqs = port:PC16<2><default><default><default>

[boot_disp]
advert_disp = 0
auto_hpd = 1
output_type = 4
hdmi_channel = 0
hdmi_mode = 4
cvbs_channel = 1
cvbs_mode = 11
output_full = 1
hdmi_mode_check = 1

[disp_init]
disp_init_enable = 1
disp_mode = 0
screen0_output_type = 3
screen0_output_mode = 5
screen1_output_type = 3
screen1_output_mode = 5
fb0_format = 0
fb0_width = 0
fb0_height = 0
fb1_format = 0
fb1_width = 0
fb1_height = 0

[hdmi_para]
hdmi_used = 1
hdmi_power = "vcc-hdmi-18"

[tv_para]
tv_used = 0
tv_dac_used = 1
tv_dac_src0 = 0

[pwm0_para]
pwm_used = 0
pwm_positive = port:PA05<3><0><default><default>

[gmac0]
gmac_used = 0
gmac_power1 =

[csi0]
vip_used = 1
vip_mode = 0
vip_dev_qty = 1
vip_define_sensor_list = 0
vip_csi_pck = port:PE00<2><default><default><default>
vip_csi_mck = port:PE01<2><default><default><default>
vip_csi_hsync = port:PE02<2><default><default><default>
vip_csi_vsync = port:PE03<2><default><default><default>
vip_csi_d0 = port:PE04<2><default><default><default>
vip_csi_d1 = port:PE05<2><default><default><default>
vip_csi_d2 = port:PE06<2><default><default><default>
vip_csi_d3 = port:PE07<2><default><default><default>
vip_csi_d4 = port:PE08<2><default><default><default>
vip_csi_d5 = port:PE09<2><default><default><default>
vip_csi_d6 = port:PE10<2><default><default><default>
vip_csi_d7 = port:PE11<2><default><default><default>
vip_csi_sck = port:PE12<2><default><default><default>
vip_csi_sda = port:PE13<2><default><default><default>
vip_dev0_mname = "gc2035"
vip_dev0_pos = "front"
vip_dev0_lane = 1
vip_dev0_twi_id = 2
vip_dev0_twi_addr = 120
vip_dev0_isp_used = 0
vip_dev0_fmt = 0
vip_dev0_stby_mode = 0
vip_dev0_vflip = 1
vip_dev0_hflip = 1
vip_dev0_iovdd = ""
vip_dev0_iovdd_vol = 2800000
vip_dev0_avdd = ""
vip_dev0_avdd_vol = 2800000
vip_dev0_dvdd = ""
vip_dev0_dvdd_vol = 1800000
vip_dev0_afvdd = ""
vip_dev0_afvdd_vol = 2800000
vip_dev0_power_en = port:PA17<1><default><default><1>
vip_dev0_reset = port:PE14<1><default><default><1>
vip_dev0_pwdn = port:PE15<1><default><default><0>
vip_dev0_flash_en =
vip_dev0_flash_mode =
vip_dev0_af_pwdn =
vip_dev0_act_used = 0
vip_dev0_act_name = "ad5820_act"
vip_dev0_act_slave = 24
vip_dev1_mname = ""
vip_dev1_pos = "rear"
vip_dev1_lane = 1
vip_dev1_twi_id = 0
vip_dev1_twi_addr =
vip_dev1_isp_used = 0
vip_dev1_fmt = 1
vip_dev1_stby_mode = 0
vip_dev1_vflip = 0
vip_dev1_hflip = 0
vip_dev1_iovdd = ""
vip_dev1_iovdd_vol = 2800000
vip_dev1_avdd = ""
vip_dev1_avdd_vol = 2800000
vip_dev1_dvdd = ""
vip_dev1_dvdd_vol = 1500000
vip_dev1_afvdd = ""
vip_dev1_afvdd_vol = 2800000
vip_dev1_power_en =
vip_dev1_reset =
vip_dev1_pwdn =
vip_dev1_flash_en =
vip_dev1_flash_mode =
vip_dev1_af_pwdn =

[tvout_para]
tvout_used =
tvout_channel_num =
tv_en =

[tvin_para]
tvin_used =
tvin_channel_num =

[di_para]
di_used = 1

[mmc0_para]
sdc_used = 1
sdc_detmode = 3
sdc_buswidth = 4
sdc_clk = port:PF02<2><1><2><default>
sdc_cmd = port:PF03<2><1><2><default>
sdc_d0 = port:PF01<2><1><2><default>
sdc_d1 = port:PF00<2><1><2><default>
sdc_d2 = port:PF05<2><1><2><default>
sdc_d3 = port:PF04<2><1><2><default>
sdc_det = port:PF06<0><1><2><default>
sdc_use_wp = 0
sdc_wp =
sdc_isio = 0
sdc_regulator = "none"
sdc_power_supply = "none"

[mmc1_para]
sdc_used = 1
sdc_detmode = 4
sdc_buswidth = 4
sdc_clk = port:PG00<2><1><3><default>
sdc_cmd = port:PG01<2><1><3><default>
sdc_d0 = port:PG02<2><1><3><default>
sdc_d1 = port:PG03<2><1><3><default>
sdc_d2 = port:PG04<2><1><3><default>
sdc_d3 = port:PG05<2><1><3><default>
sdc_det =
sdc_use_wp = 0
sdc_wp =
sdc_isio = 1
sdc_regulator = "none"
sdc_power_supply = "none"
sdc_2xmode = 1
sdc_ddrmode = 1

[mmc2_para]
sdc_used = 0
sdc_detmode = 3
sdc_buswidth = 8
sdc_clk = port:PC05<3><1><2><default>
sdc_cmd = port:PC06<3><1><2><default>
sdc_d0 = port:PC08<3><1><2><default>
sdc_d1 = port:PC09<3><1><2><default>
sdc_d2 = port:PC10<3><1><2><default>
sdc_d3 = port:PC11<3><1><2><default>
sdc_d4 = port:PC12<3><1><2><default>
sdc_d5 = port:PC13<3><1><2><default>
sdc_d6 = port:PC14<3><1><2><default>
sdc_d7 = port:PC15<3><1><2><default>
emmc_rst = port:PC16<3><1><2><default>
sdc_det =
sdc_use_wp = 0
sdc_wp =
sdc_isio = 0
sdc_regulator = "none"
sdc_power_supply = "none"
sdc_2xmode = 1
sdc_ddrmode = 1

[smc_para]
smc_used = 0
smc_rst = port:PA09<2><default><default><default>
smc_vppen = port:PA20<3><default><default><default>
smc_vppp = port:PA21<3><default><default><default>
smc_det = port:PA10<2><default><default><default>
smc_vccen = port:PA06<2><default><default><default>
smc_sck = port:PA07<2><default><default><default>
smc_sda = port:PA08<2><default><default><default>

[usbc0]
usb_used = 1
usb_port_type = 2
usb_detect_type = 0
usb_id_gpio = port:PG12<0><1><default><default>
usb_det_vbus_gpio = port:PG12<0><1><default><default>
usb_drv_vbus_gpio = port:PL02<1><0><default><0>
usb_host_init_state = 1
usb_restrict_gpio =
usb_restric_flag = 0
usb_restric_voltage = 3550000
usb_restric_capacity = 5
usb_regulator_io = "nocare"
usb_regulator_vol = 0
usb_not_suspend = 0

[usbc1]
usb_used = 1
usb_drv_vbus_gpio =
usb_restrict_gpio =
usb_host_init_state = 1
usb_restric_flag = 0
usb_regulator_io = "nocare"
usb_regulator_vol = 0
usb_not_suspend = 0

[usbc2]
usb_used = 1
usb_drv_vbus_gpio =
usb_restrict_gpio =
usb_host_init_state = 1
usb_restric_flag = 0
usb_regulator_io = "nocare"
usb_regulator_vol = 0
usb_not_suspend = 0

[usbc3]
usb_used = 1
usb_drv_vbus_gpio =
usb_restrict_gpio =
usb_host_init_state = 1
usb_restric_flag = 0
usb_regulator_io = "nocare"
usb_regulator_vol = 0
usb_not_suspend = 0

[usb_feature]
vendor_id = 6353
mass_storage_id = 1
adb_id = 2
manufacturer_name = "USB Developer"
product_name = "Android"
serial_number = "20080411"

[msc_feature]
vendor_name = "USB 2.0"
product_name = "USB Flash Driver"
release = 100
luns = 3

[serial_feature]
serial_unique = 0

[module_para]
module_num = 7
module_power0 = "vcc-wifi-33"
module_power0_vol = 0
module_power1 =
module_power1_vol =
module_power2 =
module_power2_vol =
module_power3 =
module_power3_vol =
chip_en =
lpo_use_apclk =

[wifi_para]
wifi_used = 1
wifi_sdc_id = 1
wifi_usbc_id = 2
wifi_usbc_type = 1
wl_reg_on = port:PL07<1><default><default><0>
wl_host_wake = port:PG10<0><default><default><0>
wl_host_wake_invert = 0

[bt_para]
bt_used = 0
bt_uart_id = 1
bt_rst_n =
bt_wake =
bt_host_wake =
bt_host_wake_invert = 0


[audio0]
audio_used = 1
lineout_vol = 31
cap_vol = 5
audio_hp_ldo = "none"
adcagc_used = 0
adcdrc_used = 0
dacdrc_used = 0
adchpf_used = 0
dachpf_used = 0
audio_pa_ctrl = port:PA16<1><default><default><0>

[spdif0]
spdif_used = 0
spdif_dout = port:PA17<2><1><default><default>

[audiohub]
hub_used = 0
codec_used = 1
spdif_used = 1
hdmi_used = 1

[s_cir0]
ir_used = 0
ir_rx = port:PL11<2><1><default><default>
ir_power_key_code0 = 87
ir_addr_code0 = 40704
ir_power_key_code1 = 26
ir_addr_code1 = 64260
ir_power_key_code2 = 20
ir_addr_code2 = 32640
ir_power_key_code3 = 21
ir_addr_code3 = 32640
ir_power_key_code4 = 11
ir_addr_code4 = 63240
ir_power_key_code5 = 3
ir_addr_code5 = 239
ir_power_key_code6 = 159
ir_addr_code6 = 19635
ir_power_key_code7 = 10
ir_addr_code7 = 30536
ir_power_key_code8 = 69
ir_addr_code8 = 48386
ir_power_key_code9 = 77
ir_addr_code9 = 56865
ir_power_key_code10 = 24
ir_addr_code10 = 65025
ir_power_key_code11 = 87
ir_addr_code11 = 65280
ir_power_key_code12 = 77
ir_addr_code12 = 65344

[cir]
ir_used = 1
ir_tx = port:PH07<2><default><default><default>

[dvfs_table]
pmuic_type = 1
pmu_gpio0 = port:PL06<1><1><2><1>
pmu_level0 = 11300
pmu_level1 = 1100
max_freq = 1200000000
min_freq = 480000000
LV_count = 5
LV1_freq = 1200000000
LV1_volt = 1300
LV2_freq = 1008000000
LV2_volt = 1300
LV3_freq = 912000000
LV3_volt = 1100
LV4_freq = 648000000
LV4_volt = 1100
LV5_freq = 480000000
LV5_volt = 1100

[gpu_dvfs_table]
G_LV_count = 3
G_LV0_freq = 312000000
G_LV0_volt = 1200000
G_LV1_freq = 384000000
G_LV1_volt = 1200000
G_LV2_freq = 456000000
G_LV2_volt = 1200000

[Vdevice]
Vdevice_used = 0
Vdevice_0 = port:PH10<5><1><2><default>
Vdevice_1 = port:PH11<5><1><2><default>

[s_uart0]
s_uart_used = 0
s_uart_tx = port:PL02<2><default><default><default>
s_uart_rx = port:PL03<2><default><default><default>

[s_rsb0]
s_rsb_used = 1
s_rsb_sck = port:PL00<2><1><2><default>
s_rsb_sda = port:PL01<2><1><2><default>

[s_jtag0]
s_jtag_used = 0
s_jtag_tms = port:PL04<2><1><2><default>
s_jtag_tck = port:PL05<2><1><2><default>
s_jtag_tdo = port:PL06<2><1><2><default>
s_jtag_tdi = port:PL07<2><1><2><default>

[s_powchk]
s_powchk_used = -2147483648
s_power_reg = 0
s_system_power = 50

[sim0]
scr_used = 0
scr_vccen = port:PA06<2><default><default><default>
scr_slk = port:PA07<2><default><default><default>
scr_sda = port:PA08<2><default><default><default>
scr_rst = port:PA09<2><default><default><default>
scr_det = port:PA10<2><default><default><default>

[ts0]
tsc_used = 0
tsc_clk = port:PE00<3><default><default><default>
tsc_err = port:PE01<3><default><default><default>
tsc_sync = port:PE02<3><default><default><default>
tsc_dvld = port:PE03<3><default><default><default>
tsc_d0 = port:PE04<3><default><default><default>
tsc_d1 = port:PE05<3><default><default><default>
tsc_d2 = port:PE06<3><default><default><default>
tsc_d3 = port:PE07<3><default><default><default>
tsc_d4 = port:PE08<3><default><default><default>
tsc_d5 = port:PE09<3><default><default><default>
tsc_d6 = port:PE10<3><default><default><default>
tsc_d7 = port:PE11<3><default><default><default>

[gpio_power_key]
key_used = 1
key_io = port:PL03<6><default><default><0>

[key_para]
key_used = 0
key_cnt = 5
key1_vol = 222
key2_vol = 444
key3_vol = 666
key4_vol = 857
key5_vol = 2000

[d7s_para]
d7s_used = 0
din_gpio = port:PD00<1><default><default><1>
clk_gpio = port:PD01<1><default><default><1>
stb_gpio = port:PD02<1><default><default><1>

[mali_para]
mali_used = 1
mali_clkdiv = 1
mali_extreme_freq = 600
mali_extreme_vol = 1400

[w1_para]
w1_used = 1
gpio = 20

[corekeeper]
corekeeper_enabled = 1

Anyone have any success using PA19 as a GPIO input?