Ricoh GRIV camera review

 I used a GRIV for three days. Here is my take.

The good,

• Very sharp lens
• Lightweight and compact body
• 50GB internal storage
• The RAW format is DNG.
• Crisp display
• UI is clean and intuitive.
• Built-in ND filter
• Superb image stabilization

The bad,

• Video recording is limited to 1080p at 60fps.
• Does not support HEIF.
• Display is fixed. It does not flip or articulate.
• Only supports UHS-I microSD card.

The ugly,

The camera freezes after taking dozens of pictures on a moving vehicle. I ruled out SD card incompatibility because I did not insert one. I had to pull out the battery to reboot the camera. This is why I only kept it for three days.

 

 

 

Making UEFI bootable Win 11 USB drive on Linux

I searched for making bootable win 11 drive on Linux. Many results point to WoeUSB. I read WoeUSB's code and found out I can do it manually.

Steps,

1. Format the USB drive with MBR.
2. Create two partitions, one 10MB, the other bigger than Windows installer ISO.
3. Write this image into the first partition. 
4. Format the second partition in NTFS/exFAT.
5. Copy everything inside the ISO into the second partition.
6. Umount the second partition.
7. Remove USB drive.

JetKVM review

Update on Apr 29, 2025

The device suddenly stopped working. The screen went blank. The case got very hot. I presume it had a short circuit. I emailed JetKVM but have no receive a response.

###

I received a JetKVM last week. Here is my take.

the good,

• the metal casing feels nice
• Web UI is clean, responsive, and intuitive. 

the bad,

• Although it supports IPv6 SLAAC, the IPv6 address is not shown anywhere in the Web UI or on-device screen. I had to enable developer mode and SSH into it to see the address.
• Virtual media does not support loading media from the browser yet.
  
• It uses a mini-HDMI port instead of a regular one.
• Its only USB-C port is for both power and data (HID and storage emulation). So it comes with a special USB-C cable that splits a USB-C port to a data port and a power port.
• It does not support WiFi. Good for security but bad for convenience.
• Its irregular form factor makes it difficult to mount on a rack.

I recommend it at a price of 88 USD. But if you can wait, GL.iNet's GL-RM1 might be a better choice.

Block clients of a specific AP from accessing WAN on OpenWrt 25.12

I updated this post to target the latest Openwrt 25.12 release. 

I wrote a post on blocking clients of AP from Internet access on Mikrotik router a while ago at https://jim-think.blogspot.com/2023/04/block-internet-access-for-iot-devices.html

I have become dissatisfied with MikroTik's WiFi compatibility. So I switched to Openwrt.

Steps

0. apk add kmod-nft-bridge

1. Add a WiFi interface for restricted devices.

config wifi-iface 'wifinet2'
    option device 'radio1'
    option mode 'ap'
    option ssid '<redacted>'
    option encryption 'psk2+ccmp'
    option key '<redacted>'
    option ocv '0'
    option network 'lan'   // bridged to lan
    option ieee80211w '1'
    option ifname 'no-internet'  // remember this
 

2. Create a file at  /root/no_internet.nft with following contents.

table bridge filter
delete table bridge filter
table bridge filter {
    chain prerouting {
        type filter hook prerouting priority dstnat; policy accept;
        iifname "no-internet" mark set 0x1984
    }
}

3. Add firewall rules in /etc/config/firewall

config rule
    option name 'block-no-internet'
    list proto 'all'
    option src 'lan'
    option dest 'wan'
    option target 'REJECT'
    option mark '0x1984'

config include
    option    type        'nftables'
    option    path        '/root/no_internet.nft'
    option    position    'ruleset-post' 

4. Reboot or run service firewall restart.

5. Run nft list ruleset to verify. 

References

https://wiki.nftables.org/wiki-nftables/index.php/Setting_packet_metainformation#packet_mark

https://openwrt.org/docs/guide-user/firewall/fw3_configurations/bridge 

https://openwrt.org/docs/guide-user/firewall/firewall_configuration#includes_2203_and_later_with_fw4

Viltrox 28mm F4.5 E mount AF lens review

I have been using a Viltrox AF 28mm F4.5 FE on Sony A6400 for a while. Here is my review.

Good,

• extremely thin and lightweight
  
• auto focus
  
• AF motor is quiet
• affordable
• built-in lens cover

Bad,

• Aperture is fixed at f/4.5 which is too wide for landscape.
• No manual focus mode
• No filter attachment threads
• Prominent flare
• AF motor can be heard on video recordings
• No optical stabilization (not unexpected given the price)

Remeber screen brightness in Fedora

My laptop's screen is always at the lowest brightness when resuming from sleep. It is very annoying. I found a fix.

 

Create an executable file at /usr/lib/systemd/system-sleep/brightness with following contents,

#!/usr/bin/sh

case $1 in
    pre) cp /sys/class/backlight/intel_backlight/brightness  /tmp/saved_brightness ;;
    post) cp /tmp/saved_brightness /sys/class/backlight/intel_backlight/brightness  ;;
esac

2022 Civic EX Canadian version review

Good,

• It has heated front seats and heated steering wheel.
• Handling is agile.
• Good fuel efficiency.
• It has remote start without subscriptions.
• The car does not seem to be connected to cellular networks.
• AC control has physical knobs. 
• It prompts me to add windshield washer fluid when the level is low.
  

Bad,

• Lane centering does not work as well as Toyota. It feels jerky.
  
• No wireless phone projection.
• No auto-dimming rear view mirror option.
• No Aux audio input port.
  

Ugly

• Steering wheel controls are complicated. It has toggles, wheels, and buttons.
• Seating position is low. I can see part of the hood even at the highest position.
• Only the two front door windows support one-touch up/down.
• Honda issued a recall for "sticky steering". But all three dealerships nearby ran out of parts and could not repair the recall.