4-bit MCU Availability - Again...

[Ricky]

So anyone have knowledge of truly low cost/low power MCU devices? I found this company.

http://upt-ic.com/en/index.aspx

They have a line of 4-bit MCUs. Can\'t find a way to get prices unless I call them. I expect that would not be very effective.

--

Rick C.

- Get 1,000 miles of free Supercharging
- Tesla referral code - https://ts.la/richard11209

 

[Ed Lee]

On Saturday, June 11, 2022 at 11:12:10 AM UTC-7, Ricky wrote:

So anyone have knowledge of truly low cost/low power MCU devices? I found this company.

http://upt-ic.com/en/index.aspx

They have a line of 4-bit MCUs. Can\'t find a way to get prices unless I call them. I expect that would not be very effective.

This one at least have an email you can try:

sales@tritan.com.tw

https://www.tritan.com.tw/en/Products/2/1152/4-bit-OTP-MCU

 

[Ricky]

On Saturday, June 11, 2022 at 2:23:07 PM UTC-4, Ed Lee wrote:

On Saturday, June 11, 2022 at 11:12:10 AM UTC-7, Ricky wrote:
So anyone have knowledge of truly low cost/low power MCU devices? I found this company.

http://upt-ic.com/en/index.aspx

They have a line of 4-bit MCUs. Can\'t find a way to get prices unless I call them. I expect that would not be very effective.

This one at least have an email you can try:

sa...@tritan.com.tw

https://www.tritan.com.tw/en/Products/2/1152/4-bit-OTP-MCU

No way to look at datasheets. They require you to login, but no way to register to get a login. So no idea what their products are like. I\'m not interested enough to email them if I can\'t even view a data sheet. Insane!

I recall companies (mostly Asian) who provide data sheets, where copying text is locked out! Why would anyone want to prevent me from copying details of their data sheet? It makes it very inconvenient for me to include their data in my board documentation and does NOTHING to prevent their competition from gaining access to it.

The world is weird.

Thanks for the link. At least I know of two companies who make these things. What I\'d really like to know is how many they sell each year. I\'m thinking it\'s a LOT since so many products use them. Some have suggested many of those products are using 8 bit MCUs. There\'s one Chinese company that is available on LCSC with an 8-bit MCU at about $0.03 each, qty 100. That\'s insane!

In addition to the cost, there\'s the power issue. Remote controls need to be as low power as possible.

--

Rick C.

+ Get 1,000 miles of free Supercharging
+ Tesla referral code - https://ts.la/richard11209

 

[Lasse Langwadt Christensen]

lørdag den 11. juni 2022 kl. 20.52.52 UTC+2 skrev Ricky:

On Saturday, June 11, 2022 at 2:23:07 PM UTC-4, Ed Lee wrote:
On Saturday, June 11, 2022 at 11:12:10 AM UTC-7, Ricky wrote:
So anyone have knowledge of truly low cost/low power MCU devices? I found this company.

http://upt-ic.com/en/index.aspx

They have a line of 4-bit MCUs. Can\'t find a way to get prices unless I call them. I expect that would not be very effective.

This one at least have an email you can try:

sa...@tritan.com.tw

https://www.tritan.com.tw/en/Products/2/1152/4-bit-OTP-MCU
No way to look at datasheets. They require you to login, but no way to register to get a login. So no idea what their products are like. I\'m not interested enough to email them if I can\'t even view a data sheet. Insane!

I recall companies (mostly Asian) who provide data sheets, where copying text is locked out! Why would anyone want to prevent me from copying details of their data sheet? It makes it very inconvenient for me to include their data in my board documentation and does NOTHING to prevent their competition from gaining access to it.

The world is weird.

Thanks for the link. At least I know of two companies who make these things. What I\'d really like to know is how many they sell each year. I\'m thinking it\'s a LOT since so many products use them. Some have suggested many of those products are using 8 bit MCUs. There\'s one Chinese company that is available on LCSC with an 8-bit MCU at about $0.03 each, qty 100. That\'s insane!

In addition to the cost, there\'s the power issue. Remote controls need to be as low power as possible.

istm that power isn\'t _that_ critical in a remote control, it only needs to run when you push a button and
then the major power consumption is the transmitter

 

[Ricky]

On Saturday, June 11, 2022 at 3:14:05 PM UTC-4, lang...@fonz.dk wrote:

lørdag den 11. juni 2022 kl. 20.52.52 UTC+2 skrev Ricky:
On Saturday, June 11, 2022 at 2:23:07 PM UTC-4, Ed Lee wrote:
On Saturday, June 11, 2022 at 11:12:10 AM UTC-7, Ricky wrote:
So anyone have knowledge of truly low cost/low power MCU devices? I found this company.

http://upt-ic.com/en/index.aspx

They have a line of 4-bit MCUs. Can\'t find a way to get prices unless I call them. I expect that would not be very effective.

This one at least have an email you can try:

sa...@tritan.com.tw

https://www.tritan.com.tw/en/Products/2/1152/4-bit-OTP-MCU
No way to look at datasheets. They require you to login, but no way to register to get a login. So no idea what their products are like. I\'m not interested enough to email them if I can\'t even view a data sheet. Insane!

I recall companies (mostly Asian) who provide data sheets, where copying text is locked out! Why would anyone want to prevent me from copying details of their data sheet? It makes it very inconvenient for me to include their data in my board documentation and does NOTHING to prevent their competition from gaining access to it.

The world is weird.

Thanks for the link. At least I know of two companies who make these things. What I\'d really like to know is how many they sell each year. I\'m thinking it\'s a LOT since so many products use them. Some have suggested many of those products are using 8 bit MCUs. There\'s one Chinese company that is available on LCSC with an 8-bit MCU at about $0.03 each, qty 100. That\'s insane!

In addition to the cost, there\'s the power issue. Remote controls need to be as low power as possible.
istm that power isn\'t _that_ critical in a remote control, it only needs to run when you push a button and
then the major power consumption is the transmitter

\"Isn\'t *that* critical\"? No, nothing about a remote control is *critical*. The lower the power, the better until you match the self current of the battery. Given the battery lasts as long as 10 years on the shelf, I\'ve never had a remote battery last that long. Also, the lower the current drain, the smaller the battery can be. They tend to be AAA now.

The MCU has to run all the time to \"see\" that you pressed a button. It doesn\'t have to run 100% of the time to do that, but it\'s a far cry from only when you press the button. It\'s not like the MCU is just turned off and you press a button to turn on the remote, then press the button you want to send.
I suppose they could diode OR the buttons to the MCU power connection, so the MCU is off until a button is pressed. Do they do that? I guess they want to save the cost of the diodes, so instead they use a 4-bit MCU that draws very, very little current when running.

--

Rick C.

-- Get 1,000 miles of free Supercharging
-- Tesla referral code - https://ts.la/richard11209

 

[Ed Lee]

On Saturday, June 11, 2022 at 4:09:08 PM UTC-7, Ricky wrote:

On Saturday, June 11, 2022 at 3:14:05 PM UTC-4, lang...@fonz.dk wrote:
lørdag den 11. juni 2022 kl. 20.52.52 UTC+2 skrev Ricky:
On Saturday, June 11, 2022 at 2:23:07 PM UTC-4, Ed Lee wrote:
On Saturday, June 11, 2022 at 11:12:10 AM UTC-7, Ricky wrote:
So anyone have knowledge of truly low cost/low power MCU devices? I found this company.

http://upt-ic.com/en/index.aspx

They have a line of 4-bit MCUs. Can\'t find a way to get prices unless I call them. I expect that would not be very effective.

This one at least have an email you can try:

sa...@tritan.com.tw

https://www.tritan.com.tw/en/Products/2/1152/4-bit-OTP-MCU
No way to look at datasheets. They require you to login, but no way to register to get a login. So no idea what their products are like. I\'m not interested enough to email them if I can\'t even view a data sheet. Insane!

I recall companies (mostly Asian) who provide data sheets, where copying text is locked out! Why would anyone want to prevent me from copying details of their data sheet? It makes it very inconvenient for me to include their data in my board documentation and does NOTHING to prevent their competition from gaining access to it.

The world is weird.

Thanks for the link. At least I know of two companies who make these things. What I\'d really like to know is how many they sell each year. I\'m thinking it\'s a LOT since so many products use them. Some have suggested many of those products are using 8 bit MCUs. There\'s one Chinese company that is available on LCSC with an 8-bit MCU at about $0.03 each, qty 100. That\'s insane!

In addition to the cost, there\'s the power issue. Remote controls need to be as low power as possible.
istm that power isn\'t _that_ critical in a remote control, it only needs to run when you push a button and
then the major power consumption is the transmitter
\"Isn\'t *that* critical\"? No, nothing about a remote control is *critical*.. The lower the power, the better until you match the self current of the battery. Given the battery lasts as long as 10 years on the shelf, I\'ve never had a remote battery last that long. Also, the lower the current drain, the smaller the battery can be. They tend to be AAA now.

The MCU has to run all the time to \"see\" that you pressed a button. It doesn\'t have to run 100% of the time to do that, but it\'s a far cry from only when you press the button. It\'s not like the MCU is just turned off and you press a button to turn on the remote, then press the button you want to send.
I suppose they could diode OR the buttons to the MCU power connection, so the MCU is off until a button is pressed. Do they do that? I guess they want to save the cost of the diodes, so instead they use a 4-bit MCU that draws very, very little current when running.

MCU draws very little current when sleeping, then wake up on button interrupt.

 

[boB]

On Sat, 11 Jun 2022 11:12:05 -0700 (PDT), Ricky
<gnuarm.deletethisbit@gmail.com> wrote:

So anyone have knowledge of truly low cost/low power MCU devices? I found this company.

http://upt-ic.com/en/index.aspx

They have a line of 4-bit MCUs. Can\'t find a way to get prices unless I call them. I expect that would not be very effective.

Were you able to download information on these ? The product table
has a download column on the right side but they appear to be dead,
even looking at the source there is nothing.

boB

 

[Ricky]

On Saturday, June 11, 2022 at 8:21:59 PM UTC-4, boB wrote:

On Sat, 11 Jun 2022 11:12:05 -0700 (PDT), Ricky
gnuarm.del...@gmail.com> wrote:

So anyone have knowledge of truly low cost/low power MCU devices? I found this company.

http://upt-ic.com/en/index.aspx

They have a line of 4-bit MCUs. Can\'t find a way to get prices unless I call them. I expect that would not be very effective.
Were you able to download information on these ? The product table
has a download column on the right side but they appear to be dead,
even looking at the source there is nothing.

No, I got nowhere. Tritan was no better requiring a login while not allowing you to sign up

--

Rick C.

-+ Get 1,000 miles of free Supercharging
-+ Tesla referral code - https://ts.la/richard11209

 

[Dave Platt]

In article <e71be537-a2eb-4eed-8e13-83c9e9f7b9c3n@googlegroups.com>,
Ricky <gnuarm.deletethisbit@gmail.com> wrote:

The MCU has to run all the time to \"see\" that you pressed a button. It
doesn\'t have to run 100% of the time to do that, but it\'s a far cry from
only when you press the button. It\'s not like the MCU is just turned
off and you press a button to turn on the remote, then press the button
you want to send.
I suppose they could diode OR the buttons to the MCU power connection,
so the MCU is off until a button is pressed. Do they do that? I guess
they want to save the cost of the diodes, so instead they use a 4-bit
MCU that draws very, very little current when running.

Some deep-low-power MCUs these days have specialized logic for this
purpose. There\'s a static (non-clocked) pin-state-change detection
circuit for one or more of the pins, which will operate even if the
core of the MCU is clock-stopped. In a typical implementation,
this circuit can trigger an interrupt which brings the MCU out of
a clock-stopped idle state (with some amount of latency as the
clock oscillator starts up again).

This gets the power usage down to \"static CMOS\" levels of leakage.

Fancier chips will have multiple power wells on the die, with the
ability to turn off power to non-essential peripherals and even
to the core itself. In those designs, only the pin-change
circuitry may actually be powered up when the MCU is standing
by - the core may be powered down.

 

[Martin Brown]

On 11/06/2022 19:52, Ricky wrote:

On Saturday, June 11, 2022 at 2:23:07 PM UTC-4, Ed Lee wrote:
On Saturday, June 11, 2022 at 11:12:10 AM UTC-7, Ricky wrote:
So anyone have knowledge of truly low cost/low power MCU devices? I found this company.

http://upt-ic.com/en/index.aspx

They have a line of 4-bit MCUs. Can\'t find a way to get prices unless I call them. I expect that would not be very effective.

This one at least have an email you can try:

sa...@tritan.com.tw

https://www.tritan.com.tw/en/Products/2/1152/4-bit-OTP-MCU

No way to look at datasheets. They require you to login, but no way to register to get a login. So no idea what their products are like. I\'m not interested enough to email them if I can\'t even view a data sheet. Insane!

I recall companies (mostly Asian) who provide data sheets, where copying text is locked out! Why would anyone want to prevent me from copying details of their data sheet? It makes it very inconvenient for me to include their data in my board documentation and does NOTHING to prevent their competition from gaining access to it.

The world is weird.

Thanks for the link. At least I know of two companies who make these things. What I\'d really like to know is how many they sell each year. I\'m thinking it\'s a LOT since so many products use them. Some have suggested many of those products are using 8 bit MCUs. There\'s one Chinese company that is available on LCSC with an 8-bit MCU at about $0.03 each, qty 100. That\'s insane!

In addition to the cost, there\'s the power issue. Remote controls need to be as low power as possible.

That is far from clear. Once you go below 1uA standing current the
battery life might even be slightly enhanced by a tiny current flow.

Most of them can be configured to be at least an order of magnitude less
around 0.1uA in sleep mode and have a wake up on button pressed.

--
Regards,
Martin Brown

 

[Ed Lee]

On Sunday, June 12, 2022 at 4:12:35 AM UTC-7, Martin Brown wrote:

On 11/06/2022 19:52, Ricky wrote:
On Saturday, June 11, 2022 at 2:23:07 PM UTC-4, Ed Lee wrote:
On Saturday, June 11, 2022 at 11:12:10 AM UTC-7, Ricky wrote:
So anyone have knowledge of truly low cost/low power MCU devices? I found this company.

http://upt-ic.com/en/index.aspx

They have a line of 4-bit MCUs. Can\'t find a way to get prices unless I call them. I expect that would not be very effective.

This one at least have an email you can try:

sa...@tritan.com.tw

https://www.tritan.com.tw/en/Products/2/1152/4-bit-OTP-MCU

No way to look at datasheets. They require you to login, but no way to register to get a login. So no idea what their products are like. I\'m not interested enough to email them if I can\'t even view a data sheet. Insane!

I recall companies (mostly Asian) who provide data sheets, where copying text is locked out! Why would anyone want to prevent me from copying details of their data sheet? It makes it very inconvenient for me to include their data in my board documentation and does NOTHING to prevent their competition from gaining access to it.

The world is weird.

Thanks for the link. At least I know of two companies who make these things. What I\'d really like to know is how many they sell each year. I\'m thinking it\'s a LOT since so many products use them. Some have suggested many of those products are using 8 bit MCUs. There\'s one Chinese company that is available on LCSC with an 8-bit MCU at about $0.03 each, qty 100. That\'s insane!

In addition to the cost, there\'s the power issue. Remote controls need to be as low power as possible.
That is far from clear. Once you go below 1uA standing current the
battery life might even be slightly enhanced by a tiny current flow.

Most of them can be configured to be at least an order of magnitude less
around 0.1uA in sleep mode and have a wake up on button pressed.

10uA standby will last 10 years on 1000mAh battery. If the OP is willing to spend a few more cents, an 8 bit OTP MCU is far more capable (including A2D):

https://www.holtek.com/documents/10179/116711/HT46R064B_065B_066Bv120.pdf

 

[Ricky]

On Sunday, June 12, 2022 at 7:31:58 AM UTC-4, Ed Lee wrote:

On Sunday, June 12, 2022 at 4:12:35 AM UTC-7, Martin Brown wrote:
On 11/06/2022 19:52, Ricky wrote:
On Saturday, June 11, 2022 at 2:23:07 PM UTC-4, Ed Lee wrote:
On Saturday, June 11, 2022 at 11:12:10 AM UTC-7, Ricky wrote:
So anyone have knowledge of truly low cost/low power MCU devices? I found this company.

http://upt-ic.com/en/index.aspx

They have a line of 4-bit MCUs. Can\'t find a way to get prices unless I call them. I expect that would not be very effective.

This one at least have an email you can try:

sa...@tritan.com.tw

https://www.tritan.com.tw/en/Products/2/1152/4-bit-OTP-MCU

No way to look at datasheets. They require you to login, but no way to register to get a login. So no idea what their products are like. I\'m not interested enough to email them if I can\'t even view a data sheet. Insane!

I recall companies (mostly Asian) who provide data sheets, where copying text is locked out! Why would anyone want to prevent me from copying details of their data sheet? It makes it very inconvenient for me to include their data in my board documentation and does NOTHING to prevent their competition from gaining access to it.

The world is weird.

Thanks for the link. At least I know of two companies who make these things. What I\'d really like to know is how many they sell each year. I\'m thinking it\'s a LOT since so many products use them. Some have suggested many of those products are using 8 bit MCUs. There\'s one Chinese company that is available on LCSC with an 8-bit MCU at about $0.03 each, qty 100. That\'s insane!

In addition to the cost, there\'s the power issue. Remote controls need to be as low power as possible.
That is far from clear. Once you go below 1uA standing current the
battery life might even be slightly enhanced by a tiny current flow.

Most of them can be configured to be at least an order of magnitude less
around 0.1uA in sleep mode and have a wake up on button pressed.
10uA standby will last 10 years on 1000mAh battery. If the OP is willing to spend a few more cents, an 8 bit OTP MCU is far more capable (including A2D):

https://www.holtek.com/documents/10179/116711/HT46R064B_065B_066Bv120.pdf

What makes you think you can\'t get an ADC in a 4-bit MCU?

You never understand the design process. At qty 1,000,000, no one cares about having \"more capable\" processors. They need what they need and will pay for nothing extra. I guess this doesn\'t surprise me, coming from you.

--

Rick C.

+- Get 1,000 miles of free Supercharging
+- Tesla referral code - https://ts.la/richard11209

 

[Ricky]

On Sunday, June 12, 2022 at 12:45:53 AM UTC-4, Dave Platt wrote:

In article <e71be537-a2eb-4eed...@googlegroups.com>,
Ricky <gnuarm.del...@gmail.com> wrote:

The MCU has to run all the time to \"see\" that you pressed a button. It
doesn\'t have to run 100% of the time to do that, but it\'s a far cry from
only when you press the button. It\'s not like the MCU is just turned
off and you press a button to turn on the remote, then press the button
you want to send.
I suppose they could diode OR the buttons to the MCU power connection,
so the MCU is off until a button is pressed. Do they do that? I guess
they want to save the cost of the diodes, so instead they use a 4-bit
MCU that draws very, very little current when running.
Some deep-low-power MCUs these days have specialized logic for this
purpose. There\'s a static (non-clocked) pin-state-change detection
circuit for one or more of the pins, which will operate even if the
core of the MCU is clock-stopped. In a typical implementation,
this circuit can trigger an interrupt which brings the MCU out of
a clock-stopped idle state (with some amount of latency as the
clock oscillator starts up again).

This gets the power usage down to \"static CMOS\" levels of leakage.

Fancier chips will have multiple power wells on the die, with the
ability to turn off power to non-essential peripherals and even
to the core itself. In those designs, only the pin-change
circuitry may actually be powered up when the MCU is standing
by - the core may be powered down.

On many remote controls, there are enough buttons they need to be multiplexed. I suppose it is possible to connect every I/O pin to a change detector..

\"Fancier chips\" is not what this is about. It is about the absolute lowest cost product. Even the pin state change detector might price the device above the competition. Not only is there die area costs, but tiny chips like these are dominated by the time spent on the tester.

This is the sort of situation where you can devise all sorts of fancy fasteners that have many advantages, but a nail is going to win the contest every time.

Keeping the entire chip in zero power state other than a low rate RC oscillator to wake up the device is going to win this contest every time. For the remote control, it has to wake up maybe 5 times a second to prevent perceptible lag. The CPU probable runs at a similarly slow clock rate, then shuts off. This is going on 24/7, so needs to be adequately low.

--

Rick C.

++ Get 1,000 miles of free Supercharging
++ Tesla referral code - https://ts.la/richard11209

 

[Ed Lee]

On Sunday, June 12, 2022 at 6:35:24 AM UTC-7, Ricky wrote:

On Sunday, June 12, 2022 at 12:45:53 AM UTC-4, Dave Platt wrote:
In article <e71be537-a2eb-4eed...@googlegroups.com>,
Ricky <gnuarm.del...@gmail.com> wrote:

The MCU has to run all the time to \"see\" that you pressed a button. It
doesn\'t have to run 100% of the time to do that, but it\'s a far cry from
only when you press the button. It\'s not like the MCU is just turned
off and you press a button to turn on the remote, then press the button
you want to send.
I suppose they could diode OR the buttons to the MCU power connection,
so the MCU is off until a button is pressed. Do they do that? I guess
they want to save the cost of the diodes, so instead they use a 4-bit
MCU that draws very, very little current when running.
Some deep-low-power MCUs these days have specialized logic for this
purpose. There\'s a static (non-clocked) pin-state-change detection
circuit for one or more of the pins, which will operate even if the
core of the MCU is clock-stopped. In a typical implementation,
this circuit can trigger an interrupt which brings the MCU out of
a clock-stopped idle state (with some amount of latency as the
clock oscillator starts up again).

This gets the power usage down to \"static CMOS\" levels of leakage.

Fancier chips will have multiple power wells on the die, with the
ability to turn off power to non-essential peripherals and even
to the core itself. In those designs, only the pin-change
circuitry may actually be powered up when the MCU is standing
by - the core may be powered down.
On many remote controls, there are enough buttons they need to be multiplexed. I suppose it is possible to connect every I/O pin to a change detector.

You can still multiplex on pin change interrupt. The Holtek chip has 18 to 26 pins to multiplex.

> \"Fancier chips\" is not what this is about. It is about the absolute lowest cost product. Even the pin state change detector might price the device above the competition. Not only is there die area costs, but tiny chips like these are dominated by the time spent on the tester.

So, not much difference between 4 bits or 8 bits. You are dealing with much smaller segment in 4 bit manufacturers, and they usually want more profit..

This is the sort of situation where you can devise all sorts of fancy fasteners that have many advantages, but a nail is going to win the contest every time.

Keeping the entire chip in zero power state other than a low rate RC oscillator to wake up the device is going to win this contest every time. For the remote control, it has to wake up maybe 5 times a second to prevent perceptible lag. The CPU probable runs at a similarly slow clock rate, then shuts off. This is going on 24/7, so needs to be adequately low.

The Holtek chip can run on timer interrupt at 10uA for 10 years. Spec-ing battery for more than 10 years is just meaningless.

 

[Ed Lee]

> Keeping the entire chip in zero power state other than a low rate RC oscillator to wake up the device is going to win this contest every time. For the remote control, it has to wake up maybe 5 times a second to prevent perceptible lag. The CPU probable runs at a similarly slow clock rate, then shuts off. This is going on 24/7, so needs to be adequately low.

I have done pin change interrupt on 32KHz AVR. There was no perceptible lag. It takes more time to turn on the LCD than interrupt trigging.

 

[Martin Brown]

On 12/06/2022 15:40, Ed Lee wrote:

Keeping the entire chip in zero power state other than a low rate RC oscillator to wake up the device is going to win this contest every time. For the remote control, it has to wake up maybe 5 times a second to prevent perceptible lag. The CPU probable runs at a similarly slow clock rate, then shuts off. This is going on 24/7, so needs to be adequately low.

I have done pin change interrupt on 32KHz AVR. There was no perceptible lag. It takes more time to turn on the LCD than interrupt trigging.

Humans are pretty slow when compared to a 32kHz clock. The chips I use
actually clock at 8kHz when used with a 32kHz watch xtal. You still
can\'t notice any lag on button press.

Once you are running on a low power watch crystal and in a decent low
power mode it doesn\'t make much difference to battery life whether the
thing draws 1uA or 0.1uA. Even as much as 10uA still gives you 10^5
hours or >10 years per Ah of battery.

There is a tendency to use micro button cells with lower capacities in
tiny remotes these days but even so the 24/7 CPU drain is miniscule when
compared to the transmit power of the IR or RF when sending a command.

--
Regards,
Martin Brown

 

[Ed Lee]

On Sunday, June 12, 2022 at 7:57:59 AM UTC-7, Martin Brown wrote:

On 12/06/2022 15:40, Ed Lee wrote:
Keeping the entire chip in zero power state other than a low rate RC oscillator to wake up the device is going to win this contest every time. For the remote control, it has to wake up maybe 5 times a second to prevent perceptible lag. The CPU probable runs at a similarly slow clock rate, then shuts off. This is going on 24/7, so needs to be adequately low.

I have done pin change interrupt on 32KHz AVR. There was no perceptible lag. It takes more time to turn on the LCD than interrupt trigging.
Humans are pretty slow when compared to a 32kHz clock. The chips I use
actually clock at 8kHz when used with a 32kHz watch xtal. You still
can\'t notice any lag on button press.

Once you are running on a low power watch crystal and in a decent low
power mode it doesn\'t make much difference to battery life whether the
thing draws 1uA or 0.1uA. Even as much as 10uA still gives you 10^5
hours or >10 years per Ah of battery.

There is a tendency to use micro button cells with lower capacities in
tiny remotes these days but even so the 24/7 CPU drain is miniscule when
compared to the transmit power of the IR or RF when sending a command.

We did a project with the $1 AVR and 25c Holtek equivalent OTP chip. AVR draws more power when running, but less in sleeping. Our customer did not ask for cheaper chip (in 10k Qty) or longer battery life.

 

[Three Jeeps]

On Saturday, June 11, 2022 at 2:12:10 PM UTC-4, Ricky wrote:

So anyone have knowledge of truly low cost/low power MCU devices? I found this company.

http://upt-ic.com/en/index.aspx

They have a line of 4-bit MCUs. Can\'t find a way to get prices unless I call them. I expect that would not be very effective.

--

Rick C.

- Get 1,000 miles of free Supercharging
- Tesla referral code - https://ts.la/richard11209

I personally don\'t see the need for a 4 bit cpu. I see them as costing approximately the same as 8 bit cpus because they are a \'specialty\' device. My past designs were with the TI MSP430 or the microchip. you may want to check out stmicroelectronics - STM32g031 @ $1.80 USD in 100\'s is pretty cheap. Suppose you find a 4 bit @ <$1.00 USD, I suspect the additional cost of tools and time to program will easily offset the cost.
I don\'t know all your requirements so pls take these suggestions as just that. You may have already checked them out.
J

 

[bitrex]

On 6/12/2022 6:33 PM, Three Jeeps wrote:

On Saturday, June 11, 2022 at 2:12:10 PM UTC-4, Ricky wrote:
So anyone have knowledge of truly low cost/low power MCU devices? I found this company.

http://upt-ic.com/en/index.aspx

They have a line of 4-bit MCUs. Can\'t find a way to get prices unless I call them. I expect that would not be very effective.

--

Rick C.

- Get 1,000 miles of free Supercharging
- Tesla referral code - https://ts.la/richard11209
I personally don\'t see the need for a 4 bit cpu. I see them as costing approximately the same as 8 bit cpus because they are a \'specialty\' device. My past designs were with the TI MSP430 or the microchip. you may want to check out stmicroelectronics - STM32g031 @ $1.80 USD in 100\'s is pretty cheap. Suppose you find a 4 bit @ <$1.00 USD, I suspect the additional cost of tools and time to program will easily offset the cost.
I don\'t know all your requirements so pls take these suggestions as just that. You may have already checked them out.
J

I don\'t see much power-saving advantage to a 4 bit CPU, either, modern 8
bit microcontrollers can be put into sub-uA sleep waiting on a pin
change interrupt.

 

[Ricky]

On Sunday, June 12, 2022 at 6:58:57 PM UTC-4, bitrex wrote:

On 6/12/2022 6:33 PM, Three Jeeps wrote:
On Saturday, June 11, 2022 at 2:12:10 PM UTC-4, Ricky wrote:
So anyone have knowledge of truly low cost/low power MCU devices? I found this company.

http://upt-ic.com/en/index.aspx

They have a line of 4-bit MCUs. Can\'t find a way to get prices unless I call them. I expect that would not be very effective.

--

Rick C.

- Get 1,000 miles of free Supercharging
- Tesla referral code - https://ts.la/richard11209
I personally don\'t see the need for a 4 bit cpu. I see them as costing approximately the same as 8 bit cpus because they are a \'specialty\' device. My past designs were with the TI MSP430 or the microchip. you may want to check out stmicroelectronics - STM32g031 @ $1.80 USD in 100\'s is pretty cheap. Suppose you find a 4 bit @ <$1.00 USD, I suspect the additional cost of tools and time to program will easily offset the cost.
I don\'t know all your requirements so pls take these suggestions as just that. You may have already checked them out.
J

I don\'t see much power-saving advantage to a 4 bit CPU, either, modern 8
bit microcontrollers can be put into sub-uA sleep waiting on a pin
change interrupt.

Can they be put to sleep waiting for any key on the keypad to be pressed? I\'ve just never seen a device that had that flexibility.

I was actually hoping to hear from some people who design products that sell millions and only have a need for a very limited processor, like a 4 bit device. There was one guy in particular who used to post here and designed toys. He talked about design reviews removing a resistor they felt was not important enough to retain because of the cost.

--

Rick C.

--- Get 1,000 miles of free Supercharging
--- Tesla referral code - https://ts.la/richard11209