Category: raspberrypi

raspberry pi boot long time – no boot / reboot issue fixed

I have raspberry pi 4 with raspbian os lite installed and the OS is directly installed on SSD which is connected with USB3.0 with connector USB-to-SATA. Whenever the power outage happens the pi some time boots and sometime it doesn’t and it also takes lots of time to boot 10min+

  • First I checked with below command what services are taking longer time and disabled docker and kubelet rpi-eeprom-update
root@lp-arm-3:~# systemd-analyze blame
1min 36.522s docker.service
     51.427s containerd.service
     50.609s rpi-eeprom-update.service
     50.590s user@1000.service
     50.221s ModemManager.service
     49.702s NetworkManager-wait-online.service
     38.108s apt-daily-upgrade.service
     32.277s dpkg-db-backup.service
      2.558s dev-sda2.device
      1.281s raspi-config.service
       670ms man-db.service
       613ms NetworkManager.service
       583ms keyboard-setup.service
       536ms systemd-logind.service
       512ms systemd-udev-trigger.service
       429ms systemd-journald.service


root@lp-arm-3:~# systemd-analyze
Startup finished in 36.419s (kernel) + 2min 33.375s (userspace) = 3min 9.794s 
multi-user.target reached after 2min 33.318s in userspace.



root@lp-arm-3:~# systemd-analyze critical-chain
The time when unit became active or started is printed after the "@" character.
The time the unit took to start is printed after the "+" character.

multi-user.target @2min 33.318s
└─kubelet.service @1min 6.646s
  └─network-online.target @55.038s
    └─NetworkManager-wait-online.service @5.315s +49.702s
      └─NetworkManager.service @4.687s +613ms
        └─dbus.service @4.552s +97ms
          └─basic.target @4.509s
            └─sockets.target @4.509s
              └─docker.socket @4.485s +23ms
                └─sysinit.target @4.468s
                  └─systemd-timesyncd.service @4.091s +375ms
                    └─systemd-tmpfiles-setup.service @3.805s +208ms
                      └─local-fs.target @3.777s
                        └─run-user-1000.mount @5.576s
                          └─local-fs-pre.target @1.650s
                            └─keyboard-setup.service @1.065s +583ms
                              └─systemd-journald.socket @1.019s
                                └─-.mount @946ms
                                  └─-.slice @946ms
  • This did not fix issue.
  • Main issue was USB SATA driver speed.
  • I enabled permanent logs for boot
journalctl --list-boots
journalctl -b -1

show only error

journalctl -b -1 -p err

Feb 07 20:40:53 lp-arm-3.home kernel: sd 0:0:0:0: [sda] tag#9 uas_eh_abort_handler 0 uas-tag 15 inflight: CMD OUT Feb 07 20:40:53 lp-arm-3.home kernel: sd 0:0:0:0: [sda] tag#9 CDB: opcode=0x2a 2a 00 01 50 21 78 00 00 08 00 Feb 07 20:40:53 lp-arm-3.home kernel: sd 0:0:0:0: [sda] tag#4 uas_eh_abort_handler 0 uas-tag 6 inflight: CMD Feb 07 20:40:53 lp-arm-3.home kernel: sd 0:0:0:0: [sda] tag#4 CDB: opcode=0x35 35 00 00 00 00 00 00 00 00 00 Feb 07 20:40:53 lp-arm-3.home kernel: scsi host0: uas_eh_device_reset_handler start Feb 07 20:40:53 lp-arm-3.home kernel: usb 2-2: reset SuperSpeed USB device number 2 using xhci_hcd Feb 07 20:40:53 lp-arm-3.home kernel: scsi host0: uas_eh_device_reset_handler success Feb 07 20:40:53 lp-arm-3.home kernel: sd 0:0:0:0: [sda] tag#8 UNKNOWN(0x2003) Result: hostbyte=0x07 driverbyte=DRIVER_OK cmd_age=61s Feb 07 20:40:53 lp-arm-3.home kernel: sd 0:0:0:0: [sda] tag#8 CDB: opcode=0x28 28 00 00 5e dc f8 00 00 10 00 Feb 07 20:40:53 lp-arm-3.home kernel: I/O error, dev sda, sector 6216952 op 0x0:(READ) flags 0x80700 phys_seg 2 prio class 2 Feb 07 20:40:53 lp-arm-3.home kernel: sd 0:0:0:0: [sda] tag#2 UNKNOWN(0x2003) Result: hostbyte=0x07 driverbyte=DRIVER_OK cmd_age=61s Feb 07 20:40:53 lp-arm-3.home kernel: sd 0:0:0:0: [sda] tag#2 CDB: opcode=0x28 28 00 02 88 f5 e0 00 00 30 00 Feb 07 20:40:53 lp-arm-3.home kernel: I/O error, dev sda, sector 42530272 op 0x0:(READ) flags 0x80700 phys_seg 6 prio class 2 Feb 07 20:40:53 lp-arm-3.home kernel: sd 0:0:0:0: [sda] tag#1 UNKNOWN(0x2003) Result: hostbyte=0x07 driverbyte=DRIVER_OK cmd_age=61s Feb 07 20:40:53 lp-arm-3.home kernel: sd 0:0:0:0: [sda] tag#1 CDB: opcode=0x28 28 00 00 5e cb c8 00 01 00 00 Feb 07 20:40:53 lp-arm-3.home kernel: I/O error, dev sda, sector 6212552 op 0x0:(READ) flags 0x80700 phys_seg 32 prio class 2 Feb 07 20:40:53 lp-arm-3.home kernel: sd 0:0:0:0: [sda] tag#3 UNKNOWN(0x2003) Result: hostbyte=0x07 driverbyte=DRIVER_OK cmd_age=61s Feb 07 20:40:53 lp-arm-3.home kernel: sd 0:0:0:0: [sda] tag#3 CDB: opcode=0x28 28 00 02 84 ee 68 00 00 50 00 Feb 07 20:40:53 lp-arm-3.home kernel: I/O error, dev sda, sector 42266216 op 0x0:(READ) flags 0x80700 phys_seg 10 prio class 2 Feb 07 20:40:53 lp-arm-3.home kernel: sd 0:0:0:0: [sda] tag#6 UNKNOWN(0x2003) Result: hostbyte=0x07 driverbyte=DRIVER_OK cmd_age=55s Feb 07 20:40:53 lp-arm-3.home kernel: sd 0:0:0:0: [sda] tag#6 CDB: opcode=0x28 28 00 02 80 6e 38 00 00 90 00 Feb 07 20:40:53 lp-arm-3.home kernel: I/O error, dev sda, sector 41971256 op 0x0:(READ) flags 0x80700 phys_seg 18 prio class 2 Feb 07 20:40:53 lp-arm-3.home kernel: sd 0:0:0:0: [sda] tag#7 UNKNOWN(0x2003) Result: hostbyte=0x07 driverbyte=DRIVER_OK cmd_age=49s Feb 07 20:40:53 lp-arm-3.home kernel: sd 0:0:0:0: [sda] tag#7 CDB: opcode=0x28 28 00 02 80 3c d0 00 00 58 00 Feb 07 20:40:53 lp-arm-3.home kernel: I/O error, dev sda, sector 41958608 op 0x0:(READ) flags 0x80700 phys_seg 11 prio class 2
  • The kernel is resetting the USB
  • Disabled UAS for SSD – fixed the issue
lsusb

#get the USB ID eg 7825:a2a4

vi /boot/firmware/cmdline.txt

append this line at the end

usb-storage.quirks=7825:a2a4:u

reboot

root@lp-arm-3:~# lsusb -t
/:  Bus 02.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/4p, 5000M
    |__ Port 2: Dev 2, If 0, Class=Mass Storage, Driver=usb-storage, 5000M
/:  Bus 01.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/1p, 480M
    |__ Port 1: Dev 2, If 0, Class=Hub, Driver=hub/4p, 480M

usb-storage (BOT):

sends one command at a time
waits for completion
has simpler recovery
tolerates retries and delays

BME680 sensor permanent fix for 0x77 and 0x76 on rasp pi 5

  • After reboot the 
root@pi5:~# i2cdetect -y 1
     0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f
00:                         -- -- -- -- -- -- -- -- 
10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
70: -- -- -- -- -- -- 76 --
  • After removing the power pin and reattaching
root@pi5:~# i2cdetect -y 1
     0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f
00:                         -- -- -- -- -- -- -- -- 
10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
70: -- -- -- -- -- -- -- 77
  • ValueError: No I2C device at address: 0x77
  • Solutions:
  • Some BME680 boards default to 0x76 so set it as default.
  • Update the code to try both 0x76 and 0x77

Voltage Sensor – with pico w 2

  • R1 – 7.5K
    R2 – 30K
from machine import ADC
from time import sleep

# Use ADC0 (GPIO26)
adc = ADC(26)

# Constants
VREF = 3.3              # Pico ADC reference voltage
ADC_RESOLUTION = 65535  # For read_u16() scale
DIVIDER_RATIO = 5       # Because 7.5k / (30k + 7.5k) = 0.2 → inverse is 5

def read_input_voltage():
    raw = adc.read_u16()
    v_out = (raw / ADC_RESOLUTION) * VREF
    v_in = v_out * DIVIDER_RATIO
    return round(v_in, 3)

# Main loop
while True:
    voltage = read_input_voltage()
    print("Measured Voltage:", voltage, "V")
    sleep(1)

Since the Pico ADC max is 3.3V and you’re dividing by 5: Vin max=3.3V×5=16.5VV = 3.3V \times 5 = 16.5V

Vin max​=3.3V×5=16.5V

So you can safely measure up to about 16.5 volts.

Pico 2 w – HC-SR04 ultrasonic distance sensor

Pins:

from machine import Pin, time_pulse_us
from time import sleep

# Define GPIO pins
TRIG = Pin(3, Pin.OUT)
ECHO = Pin(2, Pin.IN)

def get_distance():
    # Ensure trigger is low
    TRIG.low()
    sleep(0.002)  # Let sensor settle
    
    # Send a 10µs pulse to trigger
    TRIG.high()
    sleep(0.00001)
    TRIG.low()

    # Measure time for echo
    try:
        duration = time_pulse_us(ECHO, 1, 30000)  # 30ms timeout
    except OSError as ex:
        print("Pulse timed out")
        return None

    # Distance calculation: time (us) × speed of sound (cm/us) / 2
    distance_cm = (duration * 0.0343) / 2
    return round(distance_cm, 2)

# Main loop
while True:
    dist = get_distance()
    if dist:
        print("Distance:", dist, "cm")
    else:
        print("No distance measured.")
    sleep(1)

Pi Pico 2 W – UF2 flash – install

  • While connect to your PC first press the BOOTSEL cutton on the pico 2 w and then connect the USB
  • It will be connected as new drive(FS mode). you can view in “files”

Pico W with MQ-135 air quality sensor – Prometheus pushgateway

If you want to make portable Air quality sensor this is very easy setup. Make sure to include you mobile hostspot wifi ssid so that you can easily collect data from anywhere on the go.

Gas sensor normal takes 2-3 min to normalized it’s output vaules.

  • Pins
VCC = 3v3(OUT) - GP36
GND = GND -GP38
Input = ADC0 - GP26
  • Code
import network
import urequests
import machine
import time
import ubinascii

#only needed if sending over public ip with https.
USERNAME_P = "basic-auth-username"
PASSWORD_P = 'basic-auth-pass'

# WiFi Credentials
SSID = 'WIFI-SSID'
PASSWORD = 'WIFI-PASSWORD'

# PushGateway Configuration
PUSHGATEWAY_URL = 'https://pushgateway.example.com/metrics/job/gas_sensor/instance/pico-1/sensor/mq135'

# ADC Setup for MQ-135 on GP26 (ADC0)
adc = machine.ADC(26)

def connect_wifi():
    wlan = network.WLAN(network.STA_IF)
    wlan.active(True)
    if not wlan.isconnected():
        print('Connecting to WiFi...')
        wlan.connect(SSID, PASSWORD)
        while not wlan.isconnected():
            time.sleep(0.5)
    print('Connected, IP:', wlan.ifconfig()[0])

def read_gas_sensor():
    raw_value = adc.read_u16()  # 0–65535
    voltage = raw_value * 3.3 / 65535  # Convert to voltage if needed
    return raw_value, voltage

def send_to_pushgateway(value):
    # Prometheus format (you can include labels if you want)
    payload = f"gas_sensor_value {value}\n"
    auth_string = "{}:{}".format(USERNAME_P, PASSWORD_P)
    auth_encoded = ubinascii.b2a_base64(auth_string.encode()).decode().strip()
    
    headers = {
        "Content-Type": "text/plain",
        "Authorization": "Basic " + auth_encoded
    }
    try:
        res = urequests.post(PUSHGATEWAY_URL, data=payload, headers=headers, timeout=5)
        print("Pushed to gateway:", res.status_code)
        res.close()
    except Exception as e:
        print("Push failed:", e)

def main():
    connect_wifi()
    while True:
        raw, voltage = read_gas_sensor()
        print(f"Gas Sensor Raw: {raw} | Voltage: {voltage:.3f}V")
        send_to_pushgateway(raw)
        time.sleep(1)  # Push every 10 seconds

main()
  • timeout=5 is to fix the error code -110, [Errno 110] , ETIMEDOUT, [Errno 115] EINPROGRESS
  • Read data from pico over USB tty
#find device
dmesg | grep tty

$ read X < /dev/ttyACM0
hello
$ echo $X
Gas Sensor Raw: 2496 | Voltage: 0.126V
  • Read using screen command
screen /dev/ttyACM0

#with Baud rate

screen /dev/ttyACM0 9600

Adafruit_DHT22 python3 issue fixed – RuntimeError: Unknown platform

git clone https://github.com/adafruit/Adafruit_Python_DHT.git

cd Adafruit_Python_DHT


if [ $(cat /proc/cpuinfo | grep Hardware | wc -l) != "1" ] ; then
  cat /proc/cpuinfo > /etc/cpuinfo 
  echo -e "\nHardware       : BCM2709" >> /etc/cpuinfo 
  mount --bind /etc/cpuinfo /proc/cpuinfo
  echo "Mounted cpuinfo with Hardware info"
fi

python3 setup.py install

https://stackoverflow.com/questions/72554099/error-installing-adafruit-dht-for-python-on-raspberry-pi-400

camera raspberry pi

raspistill -o image_$(date +%s).jpg -w 480 -h 360
root@lp-arm-4:~# raspistill -o image_$(date +%s).jpg -w 480 -h 360
mmal: Cannot read camera info, keeping the defaults for OV5647
mmal: mmal_vc_component_create: failed to create component 'vc.ril.camera' (1:ENOMEM)
mmal: mmal_component_create_core: could not create component 'vc.ril.camera' (1)
mmal: Failed to create camera component
mmal: main: Failed to create camera component
mmal: Only 76M of gpu_mem is configured. Try running "sudo raspi-config" and ensure that "memory_split" has a value of 128 or greater

/boot/firmware/config.txt add gpu_mem=128

RaspberryPi Camera not detected – Ubuntu 20.04.5 LTS

Switch relay with Raspberry pi + Arduino Uno

The 5V Relay switch require that i have require around 52mA current to work properly.

  • Raspberry pi max GPIO current with 5v Relay = ?
  • Arduino pin 13 current with 5v Relay = 38.5mA
  • Arduino pin 13 + 12 current with 5v Relay = 45 mA
  • Arduino pin 13 + 12 + 2 current with 5v Relay = 47.3 mA ( This worked )

So Now i can use Arduino as a switch on/off. Also I needed this switching to be based on some external events. So I used Aurdino Pin 2 as INPUT pin and added one 2.7K ohm resistor to from pin2 to Ground.

int status = 0;

void setup() {
  pinMode(13, OUTPUT);
  pinMode(12, OUTPUT);
  pinMode(2, INPUT);
}

void loop() {
  status = digitalRead(2);
  if (status == HIGH) {
    digitalWrite(13, HIGH);
    digitalWrite(12, HIGH);
    digitalWrite(8, HIGH);
  }
  else {
    digitalWrite(13, LOW);
    digitalWrite(12, L0W);
    digitalWrite(8, LOW);
  }
}

Switch ON = 7PM
Switch OFF = 12AM

  • added Cronjob on Raspberry Pi 4
0 19 * * * /usr/bin/python3.8 /opt/led.py on
0 0 * * * /usr/bin/python3.8 /opt/led.py on

led.py

import RPi.GPIO as GPIO
from time import sleep 
import sys

GPIO.setwarnings(False)
GPIO.setmode(GPIO.BCM)
GPIO.setup(21, GPIO.OUT, initial=GPIO.LOW)

if sys.argv[1] == "on":
    GPIO.output(21, GPIO.HIGH)
    #print("on")
    exit()
elif sys.argv[1] == "off":
    GPIO.output(21, GPIO.LOW)
    #print("off")
    exit()