Qball
@qballcow.bsky.social
#lowpower, #tech, #esp32, #fpga, #rofi, #embedded
My #esp32 image frame now uses libjpeg-turbo as fallback decoder if the hardware fails. (what a pain to get that module to work..).
I also use hw blending to transition between images. This is getting pretty close to being done.
I wonder if there is interest in this project.
I also use hw blending to transition between images. This is getting pretty close to being done.
I wonder if there is interest in this project.
December 7, 2025 at 5:46 PM
My #esp32 image frame now uses libjpeg-turbo as fallback decoder if the hardware fails. (what a pain to get that module to work..).
I also use hw blending to transition between images. This is getting pretty close to being done.
I wonder if there is interest in this project.
I also use hw blending to transition between images. This is getting pretty close to being done.
I wonder if there is interest in this project.
Anybody knows the model/type of this connector. I am looking for the part that mates with this. Its from a (very old) Norma power analyzer. Not visible here, but it also has a shield on 1/2 the side.
December 7, 2025 at 11:55 AM
Anybody knows the model/type of this connector. I am looking for the part that mates with this. Its from a (very old) Norma power analyzer. Not visible here, but it also has a shield on 1/2 the side.
I've tried a MS Surface pro 2, with immich and immich kiosk.
This worked better, nice view, auto sleep/wakeup.
However its power connector is iffy, it does not make contact very well and is easily knocked loose.
Now trying to make my own using an esp32p4, not for my dad, but to scratch the itch.
This worked better, nice view, auto sleep/wakeup.
However its power connector is iffy, it does not make contact very well and is easily knocked loose.
Now trying to make my own using an esp32p4, not for my dad, but to scratch the itch.
December 7, 2025 at 11:33 AM
I've tried a MS Surface pro 2, with immich and immich kiosk.
This worked better, nice view, auto sleep/wakeup.
However its power connector is iffy, it does not make contact very well and is easily knocked loose.
Now trying to make my own using an esp32p4, not for my dad, but to scratch the itch.
This worked better, nice view, auto sleep/wakeup.
However its power connector is iffy, it does not make contact very well and is easily knocked loose.
Now trying to make my own using an esp32p4, not for my dad, but to scratch the itch.
hmm crusty.. very hard to clean the trace.
November 27, 2025 at 6:52 PM
hmm crusty.. very hard to clean the trace.
First item of my next aliexpress batch.. Regrettable this been a bit of a dud so far. 5" DSI screen.
It seems aliexpress now uses unknown shipping companies, I got a call during work: 'I got a package for you, you are not home'.. 'we have no pick up point' to 'Ill throw it on your balcony.'..
It seems aliexpress now uses unknown shipping companies, I got a call during work: 'I got a package for you, you are not home'.. 'we have no pick up point' to 'Ill throw it on your balcony.'..
November 26, 2025 at 9:12 PM
First item of my next aliexpress batch.. Regrettable this been a bit of a dud so far. 5" DSI screen.
It seems aliexpress now uses unknown shipping companies, I got a call during work: 'I got a package for you, you are not home'.. 'we have no pick up point' to 'Ill throw it on your balcony.'..
It seems aliexpress now uses unknown shipping companies, I got a call during work: 'I got a package for you, you are not home'.. 'we have no pick up point' to 'Ill throw it on your balcony.'..
New aliexpress haul.
* Another 4" display like I got recently.
* esp32p4-m3
* Two banana to crocodile clamps. (to get free shipping)
I've been wanting to try out the p4 for ages, no use case *yet*. Need to find out how to re-program the c6.
The cables are '40 Amp'..3.5mm. What will be reality.
* Another 4" display like I got recently.
* esp32p4-m3
* Two banana to crocodile clamps. (to get free shipping)
I've been wanting to try out the p4 for ages, no use case *yet*. Need to find out how to re-program the c6.
The cables are '40 Amp'..3.5mm. What will be reality.
November 14, 2025 at 11:16 AM
New aliexpress haul.
* Another 4" display like I got recently.
* esp32p4-m3
* Two banana to crocodile clamps. (to get free shipping)
I've been wanting to try out the p4 for ages, no use case *yet*. Need to find out how to re-program the c6.
The cables are '40 Amp'..3.5mm. What will be reality.
* Another 4" display like I got recently.
* esp32p4-m3
* Two banana to crocodile clamps. (to get free shipping)
I've been wanting to try out the p4 for ages, no use case *yet*. Need to find out how to re-program the c6.
The cables are '40 Amp'..3.5mm. What will be reality.
3D print this morning tore a layer of my glass print bed...
RIP sidewinder. It was old-ish, but had a nice huge print bed and happily printed stuff like ASA.
RIP sidewinder. It was old-ish, but had a nice huge print bed and happily printed stuff like ASA.
November 6, 2025 at 6:11 PM
3D print this morning tore a layer of my glass print bed...
RIP sidewinder. It was old-ish, but had a nice huge print bed and happily printed stuff like ASA.
RIP sidewinder. It was old-ish, but had a nice huge print bed and happily printed stuff like ASA.
real lug, vs amazon lug.. Spot the difference.
October 30, 2025 at 6:35 PM
real lug, vs amazon lug.. Spot the difference.
mouser is often ok to get lower quantities (as long as total is enough to get free shipping) 100 caps for £2.40
October 27, 2025 at 10:11 AM
mouser is often ok to get lower quantities (as long as total is enough to get free shipping) 100 caps for £2.40
For now lets make a control panel for it for some measuring equipment/power supplies I have.
Now to hook everything up, mqtt is the easiest, but I will need SCPI for other stuff, so maybe investigate that.
Now to hook everything up, mqtt is the easiest, but I will need SCPI for other stuff, so maybe investigate that.
October 26, 2025 at 12:20 PM
For now lets make a control panel for it for some measuring equipment/power supplies I have.
Now to hook everything up, mqtt is the easiest, but I will need SCPI for other stuff, so maybe investigate that.
Now to hook everything up, mqtt is the easiest, but I will need SCPI for other stuff, so maybe investigate that.
Another (small) aliexpress haul, a 4" 480x480 esp32s3 display module (with touchscreen). It looks good, but importantly it is not spi, but paral. interface with vsync. So I should be able to make the interface tear-free. No use for it yet, but it looks a perfect panelmount.
below the widget demo:
below the widget demo:
October 25, 2025 at 7:17 PM
Another (small) aliexpress haul, a 4" 480x480 esp32s3 display module (with touchscreen). It looks good, but importantly it is not spi, but paral. interface with vsync. So I should be able to make the interface tear-free. No use for it yet, but it looks a perfect panelmount.
below the widget demo:
below the widget demo:
Below is the discharge curve of one of the li-sodium cells. While easy to determine the capacity left, it is terrible for powering stuff.. the 4s pack starts at 16V, then you go down to 8V. I saw you can now buy a power station with these batteries, wonder how they set it up.
October 21, 2025 at 7:57 PM
Below is the discharge curve of one of the li-sodium cells. While easy to determine the capacity left, it is terrible for powering stuff.. the 4s pack starts at 16V, then you go down to 8V. I saw you can now buy a power station with these batteries, wonder how they set it up.
Showed unCAL out of nothing. Going into the menu running rom/ram test passed and it seems happy again, but not a good sign.
October 5, 2025 at 8:26 PM
Showed unCAL out of nothing. Going into the menu running rom/ram test passed and it seems happy again, but not a good sign.
Sometimes keeping your random projects around pays off. Re-building my outdoor air particle measurement node, I Wanted to know the average power usage. The meter I build around an ina228 digital power monitor is perfect for the job.
A pmsa003 sensor and a esp32c3 battery powered.
A pmsa003 sensor and a esp32c3 battery powered.
September 27, 2025 at 5:33 PM
Sometimes keeping your random projects around pays off. Re-building my outdoor air particle measurement node, I Wanted to know the average power usage. The meter I build around an ina228 digital power monitor is perfect for the job.
A pmsa003 sensor and a esp32c3 battery powered.
A pmsa003 sensor and a esp32c3 battery powered.
Testing the little board, 2.5A continuous. This should be fine, given the average usage is 0.4A. Getting > 92% efficiency for most of the range.
September 25, 2025 at 5:30 PM
Testing the little board, 2.5A continuous. This should be fine, given the average usage is 0.4A. Getting > 92% efficiency for most of the range.
@ruenahcmohr.bsky.social For my rgb led these are the curves.. Green went to past -90V, blue ~-85V, red: -33V.
I also stress tested the blue LED, it failed after a while as a short.
I also stress tested the blue LED, it failed after a while as a short.
September 22, 2025 at 4:51 PM
@ruenahcmohr.bsky.social For my rgb led these are the curves.. Green went to past -90V, blue ~-85V, red: -33V.
I also stress tested the blue LED, it failed after a while as a short.
I also stress tested the blue LED, it failed after a while as a short.
Not *cough* going down the rabbit hole of measuring random leds. A blue high-power led (the worst leds to ever be invented).
Had to bypass the interlock to go down to -75V. Now the question is, where to find a plug with this keying..
Of if somebody has the official fixture lying around.......
Had to bypass the interlock to go down to -75V. Now the question is, where to find a plug with this keying..
Of if somebody has the official fixture lying around.......
September 21, 2025 at 7:37 PM
Not *cough* going down the rabbit hole of measuring random leds. A blue high-power led (the worst leds to ever be invented).
Had to bypass the interlock to go down to -75V. Now the question is, where to find a plug with this keying..
Of if somebody has the official fixture lying around.......
Had to bypass the interlock to go down to -75V. Now the question is, where to find a plug with this keying..
Of if somebody has the official fixture lying around.......
This is a LED I know is very old (>35 years). nice different curve..
September 21, 2025 at 6:12 PM
This is a LED I know is very old (>35 years). nice different curve..
this is a red led I had lying around.. (stopped @ 10mA)
September 21, 2025 at 5:53 PM
this is a red led I had lying around.. (stopped @ 10mA)
I got the curve tracer, but not this led. Do you have a product link?
September 21, 2025 at 4:44 PM
I got the curve tracer, but not this led. Do you have a product link?
Got an old decade box from 1957 (last checked in 1981).
It is from 0.1 Ohm to 1kOhm. Regrettable 6.0 Ohm is 6.4, all others are spot on. (this unit been used by students, so amazing it works).
Contacts needs some cleaning. Anybody knows what type of grease is best to stop the contacts oxidizing?
It is from 0.1 Ohm to 1kOhm. Regrettable 6.0 Ohm is 6.4, all others are spot on. (this unit been used by students, so amazing it works).
Contacts needs some cleaning. Anybody knows what type of grease is best to stop the contacts oxidizing?
September 19, 2025 at 8:47 PM
Got an old decade box from 1957 (last checked in 1981).
It is from 0.1 Ohm to 1kOhm. Regrettable 6.0 Ohm is 6.4, all others are spot on. (this unit been used by students, so amazing it works).
Contacts needs some cleaning. Anybody knows what type of grease is best to stop the contacts oxidizing?
It is from 0.1 Ohm to 1kOhm. Regrettable 6.0 Ohm is 6.4, all others are spot on. (this unit been used by students, so amazing it works).
Contacts needs some cleaning. Anybody knows what type of grease is best to stop the contacts oxidizing?
IRF540 mosfet test.. Vgate sweep from 0 - 2.5V and
measure back Igate and Idrain.
I suspected these to be fake, but so far some measurements I took seems to match datasheet.
measure back Igate and Idrain.
I suspected these to be fake, but so far some measurements I took seems to match datasheet.
September 13, 2025 at 9:24 PM
IRF540 mosfet test.. Vgate sweep from 0 - 2.5V and
measure back Igate and Idrain.
I suspected these to be fake, but so far some measurements I took seems to match datasheet.
measure back Igate and Idrain.
I suspected these to be fake, but so far some measurements I took seems to match datasheet.
a shotkey diode.. pretty fun to do..
next to make a jig so I can test transistors.
next to make a jig so I can test transistors.
September 13, 2025 at 11:52 AM
a shotkey diode.. pretty fun to do..
next to make a jig so I can test transistors.
next to make a jig so I can test transistors.