A quick update on my keyboard project! I spun up my own basic PCB for the STM32F072RB. Dare I say it looks pretty schway.
By some stroke of luck, it worked the first time without needing any bodges. This means I can move forward with the next step of the development: Engineering the circuitry for multiplexing the optical switches. That is essentially the final big hurdle before I can make the proper circuit board for the final keyboard.
This mess of wires shows it all working perfectly.
By some stroke of luck, it worked the first time without needing any bodges. This means I can move forward with the next step of the development: Engineering the circuitry for multiplexing the optical switches. That is essentially the final big hurdle before I can make the proper circuit board for the final keyboard.
This mess of wires shows it all working perfectly.
I do not use Raspberry Pis and I recommend you don't either. There are countless alternatives that offer features that will better suit your application.
Here are my reasons why:
1. Their scarsity is such that I argue they aren't commercially available.
2. Even if you argue that they are in the legal sense, the length of time it takes to get one is too long and indeterminate they basically can't be used in deployment for anything commercial or non-hobbyist.
3. The likelihood of one failing and causing whatever it is attached to malfunction in a catastrophic manner is too high. Their only real use is for being a nerdy curiosity, such as an emulator machine or a pirated media center.
4. as far as I can tell, they have not been available at their 35$ price point for over three years. This would be pre-pandemic.
5. The hardware to get one up and running costs more than a raspi itself. You need, at a minimum, a good microSD card, a good USBC cable, a good USB wall adapter, a good enclosure, and a good mini-HDMI-to-HDMI cable. Note that I say "good" because a raspi is so fragile that "bad" ones will cause it to self-destruct. Parts that meet FCC, UL, CE and other regulatory compliance standards are not good enough. The Raspi needs ones that meet higher standards that are set arbitrarily and, to my knowledge, is not officially documented.
Iterating on point 5, I have gotten into many arguments over the peripherals I have sourced for my deployments. This is despite them all being on known-working whitelists at the time and meeting such compliance standards.
6. Personally, I have had reliability issues with All three of raspis that I have ownedin past. I will go over my three incidents here:
The first one I got was an original Raspberry Pi 1. I connected it to my TV so I could watch a video I had put onto a flash drive. When I plugged the flash drive into my pi, there was a power glitch, a puff of smoke from the pi, and my TV was bricked. It somehow destroyed my thousand dollar TV at the time just from the transient load from me hot-plugging a USB flash drive.
The second one was a Raspi 2 which had the uncapped bluetooth module. It would intermittently reset when it was powered on in my lab but not in other rooms. My lab used vacuum fluorescent bulbs at the time, and it's likely the flickering from them triggered the photoelectric effect in the uncapped bluetooth module which caused it to reset about every ten minutes.
The third one was a Raspi 3 that complained of not receiving enough voltage. It would do so even when I fed it +5.3v over vbus with a bench power supply.
There was also a fourth incident I ran into with a client. He was going to deploy a Raspi 2 (the same model with the photosensitive BT module) for a security deposit box of some sort. I showed him that I could bypass basically anything he set up by just making a sufficiently large EMP next to the bluetooth receiver. He promptly switched SBCs and found a different software and mechanical engineer for the job.
Here are my reasons why:
1. Their scarsity is such that I argue they aren't commercially available.
2. Even if you argue that they are in the legal sense, the length of time it takes to get one is too long and indeterminate they basically can't be used in deployment for anything commercial or non-hobbyist.
3. The likelihood of one failing and causing whatever it is attached to malfunction in a catastrophic manner is too high. Their only real use is for being a nerdy curiosity, such as an emulator machine or a pirated media center.
4. as far as I can tell, they have not been available at their 35$ price point for over three years. This would be pre-pandemic.
5. The hardware to get one up and running costs more than a raspi itself. You need, at a minimum, a good microSD card, a good USBC cable, a good USB wall adapter, a good enclosure, and a good mini-HDMI-to-HDMI cable. Note that I say "good" because a raspi is so fragile that "bad" ones will cause it to self-destruct. Parts that meet FCC, UL, CE and other regulatory compliance standards are not good enough. The Raspi needs ones that meet higher standards that are set arbitrarily and, to my knowledge, is not officially documented.
Iterating on point 5, I have gotten into many arguments over the peripherals I have sourced for my deployments. This is despite them all being on known-working whitelists at the time and meeting such compliance standards.
6. Personally, I have had reliability issues with All three of raspis that I have ownedin past. I will go over my three incidents here:
The first one I got was an original Raspberry Pi 1. I connected it to my TV so I could watch a video I had put onto a flash drive. When I plugged the flash drive into my pi, there was a power glitch, a puff of smoke from the pi, and my TV was bricked. It somehow destroyed my thousand dollar TV at the time just from the transient load from me hot-plugging a USB flash drive.
The second one was a Raspi 2 which had the uncapped bluetooth module. It would intermittently reset when it was powered on in my lab but not in other rooms. My lab used vacuum fluorescent bulbs at the time, and it's likely the flickering from them triggered the photoelectric effect in the uncapped bluetooth module which caused it to reset about every ten minutes.
The third one was a Raspi 3 that complained of not receiving enough voltage. It would do so even when I fed it +5.3v over vbus with a bench power supply.
There was also a fourth incident I ran into with a client. He was going to deploy a Raspi 2 (the same model with the photosensitive BT module) for a security deposit box of some sort. I showed him that I could bypass basically anything he set up by just making a sufficiently large EMP next to the bluetooth receiver. He promptly switched SBCs and found a different software and mechanical engineer for the job.
I am having trouble swallowing, but not for any reason you might think.
So for the backstory:
when I was 9, i fell off a balance beam and hit my head on it really hard. The balance beam actually hit my mouth area and chipped off the tops of my two front teeth.
They got patched up, of course, but since then my front tooth has had extreme cold sensitivity to where I have to use a straw to drink.
I am 29 now. About two months ago, I had an abscess in my gums. It turns out the nerve in one of my front teeth had died and it needed a root canal. I had that done, and since then, the cold sensitivity has completely vanished.
Here is the problem I am having:
I have tried switching away from using straws, but I simply can't. It's like I have un-learned how to drink fluid normally. If I try to take more than a large sip of water from a cup I end up inhaling it. I'm pretty sure it is not some kind of dysphagia, or trouble swallowing. The best analogy I can come up with is if someone had one of their legs paralyzed for a long time and then had that movement restored. They would need physical therapy to learn to walk again. I'm like that but with drinking water from a glass.
I have two questions:
1. is there a psychological term for this kind of phenomenon?
2. How can I teach myself to drink fluid like a normal person again?
So for the backstory:
when I was 9, i fell off a balance beam and hit my head on it really hard. The balance beam actually hit my mouth area and chipped off the tops of my two front teeth.
They got patched up, of course, but since then my front tooth has had extreme cold sensitivity to where I have to use a straw to drink.
I am 29 now. About two months ago, I had an abscess in my gums. It turns out the nerve in one of my front teeth had died and it needed a root canal. I had that done, and since then, the cold sensitivity has completely vanished.
Here is the problem I am having:
I have tried switching away from using straws, but I simply can't. It's like I have un-learned how to drink fluid normally. If I try to take more than a large sip of water from a cup I end up inhaling it. I'm pretty sure it is not some kind of dysphagia, or trouble swallowing. The best analogy I can come up with is if someone had one of their legs paralyzed for a long time and then had that movement restored. They would need physical therapy to learn to walk again. I'm like that but with drinking water from a glass.
I have two questions:
1. is there a psychological term for this kind of phenomenon?
2. How can I teach myself to drink fluid like a normal person again?
I ordered two halves of a gear for a project I was working on. The two halves were printed out of SLS nylon and one half was dyed black whereas the other was kept natural.
I left them bolted together for a bit over a year and this happened! Some of the dye from the black half leeched into the white half, permanently staining it.
For some context, SLS nylon can only be printed in white and the the only way to make it take on other colors is to boil it in Rit dye.
It's interesting to me that this can happen at all. Just thought I'd share.
I left them bolted together for a bit over a year and this happened! Some of the dye from the black half leeched into the white half, permanently staining it.
For some context, SLS nylon can only be printed in white and the the only way to make it take on other colors is to boil it in Rit dye.
It's interesting to me that this can happen at all. Just thought I'd share.