| Sysop: | Amessyroom |
|---|---|
| Location: | Fayetteville, NC |
| Users: | 21 |
| Nodes: | 6 (0 / 6) |
| Uptime: | 28:46:29 |
| Calls: | 139 |
| Files: | 91 |
| Messages: | 42,689 |
The RP2040 has a cool mode where it can be made to boot up with the
USB port looking like a memory stick. That's great for software
installs or upgrades. The Pico board has a BOOT button on the board;
if the pico is powered up with the button pushed, it goes into that
boot mode.
But if I have a product (actually a family of products) in a nice
aluminum box, a user would have to remove the top cover, remove all
power sources (there can be three), and hold the button down while reconnecting power.
Some of my customers also want to lock a box such that it's impossible
to write to any nonvolatile memory while it's in a secure area.
So here's an idea: a small hole in the box allows a toothpick or a
paper clip to push a button. A short push is a regular reset. A long
push is a memory-stick mode boot. We can have a rotary switch LOCK
hole too.
https://www.dropbox.com/scl/fi/bbhdy053xsdzv77g0brc5/B-box_Reset_Button_3.jpg?rlkey=40ozzdvczf4z8625u8i081a9b&raw=1
Does that look like it will work? The paranoid customer can pave over
the two holes, and even the end-plate screws, with an official-looking sticker.
Schmitt trigger U3 is unfortunate and likely unnecessary, but it
insures against a low-probability hazard.
The RP2040 has a cool mode where it can be made to boot up with the
USB port looking like a memory stick. That's great for software
installs or upgrades. The Pico board has a BOOT button on the board;
if the pico is powered up with the button pushed, it goes into that
boot mode.
But if I have a product (actually a family of products) in a nice
aluminum box, a user would have to remove the top cover, remove all
power sources (there can be three), and hold the button down while reconnecting power.
Some of my customers also want to lock a box such that it's impossible
to write to any nonvolatile memory while it's in a secure area.
So here's an idea: a small hole in the box allows a toothpick or a
paper clip to push a button. A short push is a regular reset. A long
push is a memory-stick mode boot. We can have a rotary switch LOCK
hole too.
https://www.dropbox.com/scl/fi/bbhdy053xsdzv77g0brc5/B-box_Reset_Button_3.jpg?rlkey=40ozzdvczf4z8625u8i081a9b&raw=1
Does that look like it will work? The paranoid customer can pave over
the two holes, and even the end-plate screws, with an official-looking sticker.
Schmitt trigger U3 is unfortunate and likely unnecessary, but it
insures against a low-probability hazard.
The RP2040 has a cool mode where it can be made to boot up with the
USB port looking like a memory stick. That's great for software
installs or upgrades. The Pico board has a BOOT button on the board;
if the pico is powered up with the button pushed, it goes into that
boot mode.
But if I have a product (actually a family of products) in a nice
aluminum box, a user would have to remove the top cover, remove all
power sources (there can be three), and hold the button down while reconnecting power.
Some of my customers also want to lock a box such that it's impossible
to write to any nonvolatile memory while it's in a secure area.
So here's an idea: a small hole in the box allows a toothpick or a
paper clip to push a button. A short push is a regular reset. A long
push is a memory-stick mode boot. We can have a rotary switch LOCK
hole too.
https://www.dropbox.com/scl/fi/bbhdy053xsdzv77g0brc5/B-box_Reset_Button_3.jpg?rlkey=40ozzdvczf4z8625u8i081a9b&raw=1At a brief glance, yes, but I donbt see why a simmle disconnect power
Does that look like it will work? The paranoid customer can pave over
the two holes, and even the end-plate screws, with an official-looking sticker.
Schmitt trigger U3 is unfortunate and likely unnecessary, but it
insures against a low-probability hazard.
On 17-Sept-24 10:58 am, john larkin wrote:
The RP2040 has a cool mode where it can be made to boot up with the
USB port looking like a memory stick. That's great for software
installs or upgrades. The Pico board has a BOOT button on the board;
if the pico is powered up with the button pushed, it goes into that
boot mode.
But if I have a product (actually a family of products) in a nice
aluminum box, a user would have to remove the top cover, remove all
power sources (there can be three), and hold the button down while
reconnecting power.
Some of my customers also want to lock a box such that it's impossible
to write to any nonvolatile memory while it's in a secure area.
So here's an idea: a small hole in the box allows a toothpick or a
paper clip to push a button. A short push is a regular reset. A long
push is a memory-stick mode boot. We can have a rotary switch LOCK
hole too.
https://www.dropbox.com/scl/fi/bbhdy053xsdzv77g0brc5/B-box_Reset_Button_3.jpg?rlkey=40ozzdvczf4z8625u8i081a9b&raw=1
Does that look like it will work? The paranoid customer can pave over
the two holes, and even the end-plate screws, with an official-looking
sticker.
Schmitt trigger U3 is unfortunate and likely unnecessary, but it
insures against a low-probability hazard.
If the board needs to be powered up, rather than just reset, while the
button is pressed, then how does your solution work? If not, then why is
the fact that there are three power supplies relevant?
Sylvia.
On 2024-09-17 04:58, john larkin wrote:switch state on the BOOT- pin after a long (5 second?) reset pulse, but that would mean a slow start on each power on.
The RP2040 has a cool mode where it can be made to boot up with the
USB port looking like a memory stick. That's great for software
installs or upgrades. The Pico board has a BOOT button on the board;
if the pico is powered up with the button pushed, it goes into that
boot mode.
But if I have a product (actually a family of products) in a nice
aluminum box, a user would have to remove the top cover, remove all
power sources (there can be three), and hold the button down while
reconnecting power.
Some of my customers also want to lock a box such that it's impossible
to write to any nonvolatile memory while it's in a secure area.
So here's an idea: a small hole in the box allows a toothpick or a
paper clip to push a button. A short push is a regular reset. A long
push is a memory-stick mode boot. We can have a rotary switch LOCK
hole too.
https://www.dropbox.com/scl/fi/bbhdy053xsdzv77g0brc5/B-box_Reset_Button_3.jpg?rlkey=40ozzdvczf4z8625u8i081a9b&raw=1
Does that look like it will work? The paranoid customer can pave over
the two holes, and even the end-plate screws, with an official-looking
sticker.
Schmitt trigger U3 is unfortunate and likely unnecessary, but it
insures against a low-probability hazard.
I used the same idea, but with less hardware. The switch triggered (RC differentiator) the reset pulse and the MCU senses the state of the switch after the reset pulse trailing edge. I used the bootloader code for that timing. The RP2040 could sense the
I think your idea would work OK, just a bit complex. Just NEVER short a cap with a switch (or relay) without a series resistor.
Arie
On 17/09/2024 03:58, john larkin wrote:
The RP2040 has a cool mode where it can be made to boot up with theThats' what my PICO powered thermostats have. For the onboard button though >Resetting is done by pulling the power.
USB port looking like a memory stick. That's great for software
installs or upgrades. The Pico board has a BOOT button on the board;
if the pico is powered up with the button pushed, it goes into that
boot mode.
But if I have a product (actually a family of products) in a nice
aluminum box, a user would have to remove the top cover, remove all
power sources (there can be three), and hold the button down while
reconnecting power.
Some of my customers also want to lock a box such that it's impossible
to write to any nonvolatile memory while it's in a secure area.
So here's an idea: a small hole in the box allows a toothpick or a
paper clip to push a button. A short push is a regular reset. A long
push is a memory-stick mode boot. We can have a rotary switch LOCK
hole too.
The point is that if you do power up with the button pressed, you wipe
the entire FLASH RAM I think.
https://www.dropbox.com/scl/fi/bbhdy053xsdzv77g0brc5/B-box_Reset_Button_3.jpg?rlkey=40ozzdvczf4z8625u8i081a9b&raw=1At a brief glance, yes, but I donbt see why a simmle disconnect power
Does that look like it will work? The paranoid customer can pave over
the two holes, and even the end-plate screws, with an official-looking
sticker.
switch in addition to the onboard switch wouldn't be as easy.
Once you start laying out a board, put everything on it you may need,
Schmitt trigger U3 is unfortunate and likely unnecessary, but it
insures against a low-probability hazard.
Can always leave it out later
On Tue, 17 Sep 2024 10:49:58 +0200, Arie de Muijnck <noreply@ademu.nl>...............
wrote:
I think your idea would work OK, just a bit complex. Just NEVER short a cap with a switch (or relay) without a series resistor.
I don't think the 10u cap will weld the contacts of the pushbutton.
Some of my customers also want to lock a box such that it's impossible
to write to any nonvolatile memory while it's in a secure area.
So here's an idea: a small hole in the box allows a toothpick or a
paper clip to push a button. A short push is a regular reset. A long
push is a memory-stick mode boot. We can have a rotary switch LOCK
hole too.
https://www.dropbox.com/scl/fi/bbhdy053xsdzv77g0brc5/B-box_Reset_Button_3.jpg?rlkey=40ozzdvczf4z8625u8i081a9b&raw=1
On 17/09/2024 03:58, john larkin wrote:
The RP2040 has a cool mode where it can be made to boot up with theThats' what my PICO powered thermostats have. For the onboard button though >Resetting is done by pulling the power.
USB port looking like a memory stick. That's great for software
installs or upgrades. The Pico board has a BOOT button on the board;
if the pico is powered up with the button pushed, it goes into that
boot mode.
But if I have a product (actually a family of products) in a nice
aluminum box, a user would have to remove the top cover, remove all
power sources (there can be three), and hold the button down while
reconnecting power.
Some of my customers also want to lock a box such that it's impossible
to write to any nonvolatile memory while it's in a secure area.
So here's an idea: a small hole in the box allows a toothpick or a
paper clip to push a button. A short push is a regular reset. A long
push is a memory-stick mode boot. We can have a rotary switch LOCK
hole too.
The point is that if you do power up with the button pressed, you wipe
the entire FLASH RAM I think.
On Tue, 17 Sep 2024 11:07:17 +0100, The Natural Philosopher <tnp@invalid.invalid> wrote:
On 17/09/2024 03:58, john larkin wrote:
The RP2040 has a cool mode where it can be made to boot up with theThats' what my PICO powered thermostats have. For the onboard button though >> Resetting is done by pulling the power.
USB port looking like a memory stick. That's great for software
installs or upgrades. The Pico board has a BOOT button on the board;
if the pico is powered up with the button pushed, it goes into that
boot mode.
But if I have a product (actually a family of products) in a nice
aluminum box, a user would have to remove the top cover, remove all
power sources (there can be three), and hold the button down while
reconnecting power.
Some of my customers also want to lock a box such that it's impossible
to write to any nonvolatile memory while it's in a secure area.
So here's an idea: a small hole in the box allows a toothpick or a
paper clip to push a button. A short push is a regular reset. A long
push is a memory-stick mode boot. We can have a rotary switch LOCK
hole too.
The point is that if you do power up with the button pressed, you wipe
the entire FLASH RAM I think.
My Pi guy verifies that entering boot mode doesn't change the contents
of flash. Power cycle and things run like before.
You had me worried!
On 17/09/2024 17:09, john larkin wrote:
On Tue, 17 Sep 2024 11:07:17 +0100, The Natural Philosopher
<tnp@invalid.invalid> wrote:
On 17/09/2024 03:58, john larkin wrote:
The RP2040 has a cool mode where it can be made to boot up with theThats' what my PICO powered thermostats have. For the onboard button though >>> Resetting is done by pulling the power.
USB port looking like a memory stick. That's great for software
installs or upgrades. The Pico board has a BOOT button on the board;
if the pico is powered up with the button pushed, it goes into that
boot mode.
But if I have a product (actually a family of products) in a nice
aluminum box, a user would have to remove the top cover, remove all
power sources (there can be three), and hold the button down while
reconnecting power.
Some of my customers also want to lock a box such that it's impossible >>>> to write to any nonvolatile memory while it's in a secure area.
So here's an idea: a small hole in the box allows a toothpick or a
paper clip to push a button. A short push is a regular reset. A long
push is a memory-stick mode boot. We can have a rotary switch LOCK
hole too.
The point is that if you do power up with the button pressed, you wipe
the entire FLASH RAM I think.
My Pi guy verifies that entering boot mode doesn't change the contents
of flash. Power cycle and things run like before.
You had me worried!
Really?
I guess whenever I entered that mode it was to download fresh code...
In comp.sys.raspberry-pi john larkin <JL@gct.com> wrote:
Some of my customers also want to lock a box such that it's impossible
to write to any nonvolatile memory while it's in a secure area.
So here's an idea: a small hole in the box allows a toothpick or a
paper clip to push a button. A short push is a regular reset. A long
push is a memory-stick mode boot. We can have a rotary switch LOCK
hole too.
https://www.dropbox.com/scl/fi/bbhdy053xsdzv77g0brc5/B-box_Reset_Button_3.jpg?rlkey=40ozzdvczf4z8625u8i081a9b&raw=1
Looks neat. But I wonder if there's a mechanical solution. eg give the >customer a loop to put a padlock through to lock the lid, and hide the boot >button behind, such that they can't press it without undoing the
padlock. Could even be something simple like a Kensington lock slot where >the boot button is deeply recessed in the slot - you have to stick a >screwdriver in the slot and can't do so if there's a lock inserted.
Of course that might cost more than your solution, so you can probably
ignore me :)
Theo
On Tue, 17 Sep 2024 17:21:36 +0100, The Natural Philosopher ><tnp@invalid.invalid> wrote:
On 17/09/2024 17:09, john larkin wrote:
On Tue, 17 Sep 2024 11:07:17 +0100, The Natural Philosopher
<tnp@invalid.invalid> wrote:
On 17/09/2024 03:58, john larkin wrote:
The RP2040 has a cool mode where it can be made to boot up with theThats' what my PICO powered thermostats have. For the onboard button though
USB port looking like a memory stick. That's great for software
installs or upgrades. The Pico board has a BOOT button on the board; >>>>> if the pico is powered up with the button pushed, it goes into that
boot mode.
But if I have a product (actually a family of products) in a nice
aluminum box, a user would have to remove the top cover, remove all
power sources (there can be three), and hold the button down while
reconnecting power.
Some of my customers also want to lock a box such that it's impossible >>>>> to write to any nonvolatile memory while it's in a secure area.
So here's an idea: a small hole in the box allows a toothpick or a
paper clip to push a button. A short push is a regular reset. A long >>>>> push is a memory-stick mode boot. We can have a rotary switch LOCK
hole too.
Resetting is done by pulling the power.
The point is that if you do power up with the button pressed, you wipe >>>> the entire FLASH RAM I think.
My Pi guy verifies that entering boot mode doesn't change the contents
of flash. Power cycle and things run like before.
You had me worried!
Really?
I guess whenever I entered that mode it was to download fresh code...
It looks like a USB memory stick. You can delete or add files if you
want.
It boots CPU 0 (the one we call Alice) from a file with the extension
.UL2
Why .UL2 one wonders.
We'll put a bunch of files into the flash. Code for Bob, the 2nd CPU.
An FPGA bitstream file. A prototype calibration table. A README file
to explain everything in plain English.
If you copy a bunch of files into the flash, Windows will lie about
what's there, but there is really only one. If you disconnect the USB
cable and reconnect, Windows will show the one file.
On Tue, 17 Sep 2024 17:21:36 +0100, The Natural Philosopher <tnp@invalid.invalid> wrote:
On 17/09/2024 17:09, john larkin wrote:
On Tue, 17 Sep 2024 11:07:17 +0100, The Natural Philosopher
<tnp@invalid.invalid> wrote:
On 17/09/2024 03:58, john larkin wrote:
The RP2040 has a cool mode where it can be made to boot up with theThats' what my PICO powered thermostats have. For the onboard button though
USB port looking like a memory stick. That's great for software
installs or upgrades. The Pico board has a BOOT button on the board; >>>>> if the pico is powered up with the button pushed, it goes into that
boot mode.
But if I have a product (actually a family of products) in a nice
aluminum box, a user would have to remove the top cover, remove all
power sources (there can be three), and hold the button down while
reconnecting power.
Some of my customers also want to lock a box such that it's impossible >>>>> to write to any nonvolatile memory while it's in a secure area.
So here's an idea: a small hole in the box allows a toothpick or a
paper clip to push a button. A short push is a regular reset. A long >>>>> push is a memory-stick mode boot. We can have a rotary switch LOCK
hole too.
Resetting is done by pulling the power.
The point is that if you do power up with the button pressed, you wipe >>>> the entire FLASH RAM I think.
My Pi guy verifies that entering boot mode doesn't change the contents
of flash. Power cycle and things run like before.
You had me worried!
Really?
I guess whenever I entered that mode it was to download fresh code...
It looks like a USB memory stick. You can delete or add files if you
want.
It boots CPU 0 (the one we call Alice) from a file with the extension
.UL2
Why .UL2 one wonders.
We'll put a bunch of files into the flash. Code for Bob, the 2nd CPU.
An FPGA bitstream file. A prototype calibration table. A README file
to explain everything in plain English.
