atmega328p small (SMD) alternative with more memory?

[NeverDie]

@anticimex Yeah, the title was ambiguous. Looking back, your interpretation is probably closer than mine as to what he meant though.

[alexsh1]

@anticimex you are absolutely correct. It does not have to be binary identical to atmega328p. However, size wise, it has to be small enough.

For now atmega1284p is a direct replacement for atmega328p as code is almost identical. I do not need much more processing power just memory. However, I did struggle to find a very small footprint.

[tbowmo]

@alexsh1

Hmm.. perhaps I should pick up on the SenseBender MK2 again.. I lost focus as I had a lot of other projects running at the same time..

If I remember right, it had problems in it's bootup sequence when I left it alone last..

[NeverDie]

In terms of BOM cost, it would be cheaper to add a second atmega328p (or even multiple) than to use a 1284. Maybe worth considering if memory of just one is insufficient.

[tbowmo]

@NeverDie

You will then waste memory with "intercom" between the devices. As they have to speak together in some way..

[alexsh1]

@neverdie Did you see any small devices with two atmega328p?
Unfortunately, atmega1284p is more pricey (Moteino Mega is $15.95 on sale right now) and size wise it is much larger than atmega328p-au projects.

[NeverDie]

@alexsh1 said in atmega328p small (SMD) alternative with more memory?:

Unfortunately, atmega1284p is more pricey (Moteino Mega is $15.95 on sale right now) and size wise it is much larger than atmega328p-au projects.

Yes, that's what I was trying to say.

[NeverDie]

On the other hand, if you go with the cheapest source, the 1284p is not too bad. Here's the cheapest I could find:
https://www.aliexpress.com/item/ATMEGA1284P-AU-ATMEGA1284P-ATMEGA1284-TQFP44/32864539405.html?spm=2114.search0104.3.1.2efd4b5asFo5Vr&ws_ab_test=searchweb0_0,searchweb201602_5_10152_10065_10151_10344_10068_10130_10324_10342_5722912_10547_10325_10343_10546_10340_10341_10548_5722612_10698_10545_10697_10696_5722812_10084_10083_10618_5722712_10307_5711215_10059_10534_308_100031_10103_441_10624_10623_10622_5711315_10621_5723012_10620_5722512,searchweb201603_1,ppcSwitch_5&algo_expid=2d7e9a21-bc2a-4ce1-bfa8-6246a79e84df-0&algo_pvid=2d7e9a21-bc2a-4ce1-bfa8-6246a79e84df&priceBeautifyAB=0

[alexsh1]

@neverdie said in atmega328p small (SMD) alternative with more memory?:

https://www.aliexpress.com/item/ATMEGA1284P-AU-ATMEGA1284P-ATMEGA1284-TQFP44/32864539405.html?spm=2114.search0104.3.1.2efd4b5asFo5Vr&ws_ab_test=searchweb0_0,searchweb201602_5_10152_10065_10151_10344_10068_10130_10324_10342_5722912_10547_10325_10343_10546_10340_10341_10548_5722612_10698_10545_10697_10696_5722812_10084_10083_10618_5722712_10307_5711215_10059_10534_308_100031_10103_441_10624_10623_10622_5711315_10621_5723012_10620_5722512,searchweb201603_1,ppcSwitch_5&algo_expid=2d7e9a21-bc2a-4ce1-bfa8-6246a79e84df-0&algo_pvid=2d7e9a21-bc2a-4ce1-bfa8-6246a79e84df&priceBeautifyAB=0

I paid around £3.5 (about $5) and thought it was the cheapest. WOW!

[alexsh1]

My new toy (atmega1284p) - Mightyduino
However, I have to think about connecting radio as this is just a bare board.
Size wise it is quite small

[tochinet]

@alexsh1 Wouldn"t a teensy 3.sth fill all the requirements ? Or an ESP8266 if you don't need ADC mux. ESP32 is you do.

[RWoerz]

@tochinet
If you don't need a lot of them use a Mega it has lots more memory. They're much cheaper than they used to be. Of course an ESP8266 will also work if you don't need all the pins.

[coddingtonbear]

You might want to consider the STM32F103 -- they're programmable over serial in much the same way that traditional ATMEGA chips are, are arduino-compatible, can be found for roughly the same price as the 1284p, are a ton faster, and most versions have a ton more memory and flash.

You can see the full lineup of chips here: http://www.st.com/en/microcontrollers/stm32f103.html?querycriteria=productId=LN1565 -- I've personally used the STM32F103CB and STM32F103RE in a handful of projects lately.

[alexsh1]

@tochinet esp8266 and esp32 are hardly smaller than mega. Teensy is a good option. There is even an adapter to hook it up to Rfm69

[alexsh1]

@coddingtonbear interesting! Did you have any experience with STM32L0 (more suitable for battery power)? Do they have anything small enough?

[NeverDie]

@coddingtonbear said in atmega328p small (SMD) alternative with more memory?:

STM32F103

Does it have any advantages over the ARM used in the nRF52832? The nRF52832 SoC is built around a 32-bit ARM® Cortex™-M4F CPU with 512kB + 64kB RAM. Not sure about other features, but I believe the nRF52832 wins on flash and RAM size.

[mfalkvidd]

@neverdie stm32 supports up to 51 i/o pins, compared to 32 for the nrf52. But very few projects need that many pins.

[mfalkvidd]

There are some small stm32 boards that pack a lot of io though. I like the double row approah. Not breadboard friendly, but very compact. Are there similar nrf5 boards?

[coddingtonbear]

@alexsh1 I'm afraid I've only used STM32F103 variants. Although the Arduino core I've used (https://github.com/rogerclarkmelbourne/Arduino_STM32) is STM32F103 specific, it does look like the official core has support for that chip, though: https://github.com/stm32duino/Arduino_Core_STM32. Just keep in mind that different chips have differing capabilities as far as programming is concerned; I do think the STM32F103 is the most limited of them, though -- you can find details about the bootloader version for each chip here: http://www.st.com/content/ccc/resource/technical/document/application_note/b9/9b/16/3a/12/1e/40/0c/CD00167594.pdf/files/CD00167594.pdf/jcr:content/translations/en.CD00167594.pdf .

[coddingtonbear]

@neverdie Not sure -- I do know that the STM32 lineup goes as high as a whole megabyte of flash and 96k of ram -- just a little north of the numbers you've quoted for the nRF52832. I have to say that I haven't looked into that specific chip in much depth, though, given that my recent projects have needed low power consumption and lots of pins more than they do onboard BLE. I have used the ESP32 on a few projects in that category though!