[Solved / Archived] Witty pi 2 with Raspberry Pi 4

It is possible that your Raspberry Pi 4 could not complete the boot due to low input voltage. Maybe the +5V and GND pins in GPIO header were not well connected to Witty Pi's corresponding pins, and hence generated some voltage drop.

Another possibility is that you installed the latest Raspberry Pi OS into your Pi, which has moved /boot/config.txt to /boot/firmware/config.txt (detailed discussions here), and Witty Pi's software installation script still writes to the old /boot/config.txt file, which doesn't take effect anymore. As a result the serial port was not properly configured, and TXD pin will not go to 3.3V during the boot, and hence Witty Pi cuts the power. If it is the case, you may copy those content in /boot/config.txt to /boot/firmware/config.txt file to fix this. 

Witty Pi 2 has been discontinued for 4+ years and we will not update its software installation script to adapt the latest Raspberry Pi OS.

Thank you for replying!

I want to mention that I didn't change, basically, anything between the two systems. The only thing that was changed between the 2 cases is the power supply (But 5V, 3A is enough.. Isn't it?)

*This is /boot/config.txt:

DO NOT EDIT THIS FILE

The file you are looking for has moved to /boot/firmware/config.txt
dtparam=i2c1=on
dtparam=i2c_arm=on
dtoverlay=pi3-miniuart-bt
core_freq=250

*And this is /boot/firmware/config.txt:

GNU nano 7.2 /boot/firmware/config.txt
# For more options and information see
# http://rptl.io/configtxt
# Some settings may impact device functionality. See link above for details

# Uncomment some or all of these to enable the optional hardware interfaces
dtparam=i2c_arm=on
#dtparam=i2s=on
dtparam=spi=on

# Enable audio (loads snd_bcm2835)
dtparam=audio=on

# Additional overlays and parameters are documented
# /boot/firmware/overlays/README

# Automatically load overlays for detected cameras
camera_auto_detect=1

# Automatically load overlays for detected DSI displays
display_auto_detect=1

# Automatically load initramfs files, if found
auto_initramfs=1

# Enable DRM VC4 V3D driver
dtoverlay=vc4-kms-v3d
max_framebuffers=2

# Don't have the firmware create an initial video= setting in cmdline.txt.
# Use the kernel's default instead.
disable_fw_kms_setup=1

# Run in 64-bit mode
arm_64bit=1

# Disable compensation for displays with overscan
disable_overscan=1

# Run as fast as firmware / board allows
arm_boost=1

[cm4]
# Enable host mode on the 2711 built-in XHCI USB controller.
# This line should be removed if the legacy DWC2 controller is required
# (e.g. for USB device mode) or if USB support is not required.
otg_mode=1

[all]

dtoverlay=w1-gpio,gpiopin=27

____________________________________

However, I've made something that could be the reason. Once, when I have been trying to mount the Witty Pi 2 on my raspi, I made a mistake; I have passed a row.. For instance, if we look to the pinout, we find that I have connected the 3V of the Witty Pi with the GPIO2 of the raspberry pi. But as I said early, the witty pi 2 is still detected when the power supply comes from the raspi.

So it's not burned or sthg :))

Any idea?

Posted by: @admin

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It is possible that your Raspberry Pi 4 could not complete the boot due to low input voltage. Maybe the +5V and GND pins in GPIO header were not well connected to Witty Pi's corresponding pins, and hence generated some voltage drop.

Have you checked this already? You can confirm it by measuring the actual voltage on the +5V pin in GPIO header, on Witty Pi's side and also on Raspberry Pi's side.

@admin Yes I have already done that: It's 5.3x for both of them. And also for +3V, GND it's 3.3V for both.

However, something bizarre started to exist today: The raspberry pi sometimes opens. However when I set a schedule and then shutdown my raspi, in the normal case The LED of the raspberry pi used to be turned off.. But now a red led is still there, and when the time of starting comes, it do not opens. 

Another strange thing happened, I can't anymore open the witty pi 2 using the button :))

If the red LED on Raspberry Pi stays ON after the Pi has been shut down, usually that's because the TXD pin didn't go LOW after shutdown. Witty Pi expects the voltage on TXD go to ~0V after shutdown, it should be the case when the serial port is properly configured. However sometimes the TXD pin doesn't go low after shutdown, it could be due to:

• Other hardware strongly pull up the TXD pin
• The Pi crashed during the shutdown

For the second case, Witty Pi 2 can do nothing about it. Witty Pi 4 (with firmware 0x05) can handle this case: it will make sure the power still be cut, as long as the shutdown is known to be initiated.

If the power is not cut after shutdown, Witty Pi can never turn on your Pi again, not even when you tap on the button. The only way out is to disconnect the power supply and reconnect it.