Chip Recommendation

Hi all,

Was wondering if anyone could recommend a chip in the Arduino (or Mighty Core) family that might fit my bill.

I need something to control a LoRa radio using RadioHead, but all it has to do is take in Serial and ship it out over radio and vice versa. It’s literally just a bridge from Serial to Lora. The code on it will be minimal except for the RadioHead library.

With that in mind I need SPI plus a reset line and a hardware interrupt. That’s 6 pins and one has to be a hardware interrupt (pin 2 or 3 on an UNO etc) for the radio. Plus I need a USART so I can put it on Serial. So that’s 8 pins, a USART, hardware SPI, at least one hardware interrupt, and at least one other digital IO pin.

I have ATTINY85 which could probably handle the code but doesn’t have the pins. I have ATMEGA328P and 1284P which could definitely take the code but are both way overkill on pins.

What’s in the middle that I can use with Arduino?

EDIT: Also needs to be DIP so I can solder it on perf board.

TIA

There are LoRa devices that have UART front ends built in.

Ebyte for instance.

The ATtiny84 is like an ATtiny85 with 14 pins. Both have a USI for serial, not a USART.

The ATmega168P is a 328P with half the flash, RAM and EEPROM but same pins and does have a USART.

Your description has not ruled out an Atmega 328 - what harm if it has some extra pins?

If you need the capability in a small package then the Attiny1634 fits the bill. It is only available in SOIC format but if you have a steady hand it is not difficult to solder wires to it.

I "converted" another SOIC to perfboard by soldering header pins into the perfboard, gluing the SOIC chip upside down between the pins with a bit of double-sided sticky foam and then soldering wires from the SOIC tabs to the header pins. (Heath Robinson aka Rube Goldberg lives on)

...R

Delta_G:
Hi all,

Was wondering if anyone could recommend a chip in the Arduino (or Mighty Core) family that might fit my bill.

I need something to control a LoRa radio using RadioHead, but all it has to do is take in Serial and ship it out over radio and vice versa. It's literally just a bridge from Serial to Lora. The code on it will be minimal except for the RadioHead library.

With that in mind I need SPI plus a reset line and a hardware interrupt. That's 6 pins and one has to be a hardware interrupt (pin 2 or 3 on an UNO etc) for the radio. Plus I need a USART so I can put it on Serial. So that's 8 pins, a USART, hardware SPI, at least one hardware interrupt, and at least one other digital IO pin.

I have ATTINY85 which could probably handle the code but doesn't have the pins. I have ATMEGA328P and 1284P which could definitely take the code but are both way overkill on pins.

What's in the middle that I can use with Arduino?

EDIT: Also needs to be DIP so I can solder it on perf board.

TIA

How about an AT Tiny 2313 or 4313? The device is available in P-DIP 20 pins.

Parametrics

Program Memory Type
Flash

Program Memory Size (KB)
4

CPU Speed (MIPS/DMIPS)
20

SRAM Bytes
256

Data EEPROM/HEF (bytes)
256

Digital Communication Peripherals
1-UART, 2-SPI, 1-I2C

Capture/Compare/PWM Peripherals
1 Input Capture, 1 CCP, 4PWM

Timers
1 x 8-bit, 1 x 16-bit

Number of Comparators
1

Temperature Range (°C)
-40 to 85

Operating Voltage Range (V)
1.8 to 5.5

Pin Count
20

Low Power
Yes

See datasheet: http://ww1.microchip.com/downloads/en/DeviceDoc/doc8246.pdf

The ATtiny841 fits the bill perfectly.
It's basically a souped up ATtiny84a with a.o. hardware UART and SPI.
Not available in DIP package but of course you can just solder it onto a SOP14 to DIP14 adapter board.

wvmarle:
The ATtiny841 fits the bill perfectly.
It's basically a souped up ATtiny84a with a.o. hardware UART and SPI.
Not available in DIP package but of course you can just solder it onto a SOP14 to DIP14 adapter board.

Well the OP specifically said he needed a DIP package...

That's so easily overcome with a simple breakout board which in turn can be soldered on perfboard just fine, that it's not a serious issue. 1.27mm SOP is really easy to hand solder.

Robin2:
Your description has not ruled out an Atmega 328 - what harm if it has some extra pins?

I know. That's probably what I end up with because I already have them here. It just makes the board larger than it has to be.

I bump into this a lot where the tiny85 is too small and the 328P is overkill. If there's something good in the middle I might buy a handful to keep for this sort of stuff.

GoForSmoke:
The ATtiny84 is like an ATtiny85 with 14 pins. Both have a USI for serial, not a USART.

That sounds exactly like the size of chip I'm looking for. Maybe not for this project, but that sounds like the thing I want in my drawer that I don't have.

krupski:
How about an AT Tiny 2313 or 4313? The device is available in P-DIP 20 pins.

That sounds like a winner if Mouser has them.

Delta_G:
That sounds like a winner if Mouser has them.

886 in stock, $1.33 each.

wvmarle:
That's so easily overcome with a simple breakout board which in turn can be soldered on perfboard just fine, that it's not a serious issue. 1.27mm SOP is really easy to hand solder.

True, but not everyone is skilled at hand soldering SMT. Also, you would need to solder header pins onto the breakout board, and then what? You can't plug fat 0.025 pins into a DIP ic socket. I personally would never solder it directly to the board.

Gotta have a socket. Murphy guarantees that the MCU will need to be replaced if it's soldered in, then he gets extra revenge by wrecking the pcb traces as you try to remove the bad chip.

Search your feelings. You know this to be true. :slight_smile:

This is the 21 century. Every serious tinkerer should have a rework station for hot air soldering.
Replacing an SMD chip is a 20-second job, and can be done many times without harming the circuit board.
Leo..

Wawa:
This is the 21 century. Every serious tinkerer should have a rework station for hot air soldering.
Replacing an SMD chip is a 20-second job, and can be done many times without harming the circuit board.
Leo..

Replacing a socketed DIP package is less than a 20 second job and does not require a rework station and can be done many, many times without harming the circuit board.

I'm beginning to wonder why I came back here. Is it possible that I actually enjoy banging my head against the wall and being kicked in the behind at the same time?

krupski:
I'm beginning to wonder why I came back here. Is it possible that I actually enjoy banging my head against the wall and being kicked in the behind at the same time?

Scratching my head why that would offend you. Sorry if it did.
I simply stated that replacing an SMD chip should not be a problem.
Rework stations are less than $40 on ebay.

I still remember reading your informative posts about replacing the 16MHz resonators for a 20/25MHz crystal.
(think it was you). How the heck did you do that without a hot air tool.
Good to see you back here.
Leo..

How about an AT Tiny 2313 or 4313? The device is available in P-DIP 20 pins.
Ok for this application but maybe not so useful as a general purpose chip because it has no adc.

Is that Krupski as in Officer Krupski of West Side Story? Because you know how that song ends...

Last I checked, this forum is mostly hobbyists. SERIOUS work is what AVR-Freaks do!

The only serious electronics tinkerers I have known all had EE degrees and a healthy respect for Murphy's Law and the infinite corollaries of that like if you tighten all the screws, you will have to take them all out.

GoForSmoke:
Is that Krupski as in Officer Krupski of West Side Story? Because you know how that song ends...

Last I checked, this forum is mostly hobbyists. SERIOUS work is what AVR-Freaks do!

The only serious electronics tinkerers I have known all had EE degrees and a healthy respect for Murphy's Law and the infinite corollaries of that like if you tighten all the screws, you will have to take them all out.

To be honest and blunt, half of the regulars here greet noobs with sarcasm while providing zero help that was asked for.

Also, many times wrong or absurd advice is presented by these same people as fact when indeed they know little to nothing about what they are discussing and all they do is parrot and regurgitate "facts" that they read somewhere.

No matter what help or advice is given, there is a clique here that NEEDS to either add pointless "Captain Obvious" information to the thread, or else simply state that the advice is somehow wrong.

I rarely ask for any help here... I usually give it, and I only give information that I know is right. I also try to ascess the knowledge level of a person who posted a question and reply accordingly, with examples or analogies that may help understanding.

Giving an idiotic, insulting reply to a question such as "use the code tags" or "read the datasheet" will accomplish nothing other than to infuriate and drive away members. Is that what we really want???

Sure, tell them to use code tags so we can better help them, but then at least attempt TO help a little. I doubt anyone comes here just to be scolded because they are not familiar with this board's text formatting tools (especially when their post count is 1).

Lastly, yes indeed I know how the Officer Krupski song ends. Is that what I'm being told? I can always go back to Avr freaks where at least I won't be insulted and corrected by "hobbiests". I am, after all, an engineer. Haven't been a noob for decades.

What do you suggest?

Wawa:
I still remember reading your informative posts about replacing the 16MHz resonators for a 20/25MHz crystal.
(think it was you). How the heck did you do that without a hot air tool.
Good to see you back here.
Leo..

Yes it was me that replaced the resonator with a teeny tiny 2-smd crystal. How did I do it? With my hot air tool.

Earlier in this thread I said that "not everyone is skilled at smd soldering" (also implying that not everyone has a hot air tool).

I never said that I didn't have one. :slight_smile:

6v6gt:

How about an AT Tiny 2313 or 4313? The device is available in P-DIP 20 pins.
Ok for this application but maybe not so useful as a general purpose chip because it has no adc.

You're right... it's got an analog comparator, but not an ADC. You probably could fudge one at 8 bits resolution by using an R/2R ladder and doing a successive approximation compare of the input vs the ladder (it would use 10 pins and several lines of code!).

Not too efficient.

krupski:
To be honest and blunt, half of the regulars here greet noobs with sarcasm while providing zero help that was asked for.

I have said it before, indeed recently in another Thread, please provide some examples to support your allegations.

I'm am well aware that there is a wide diversity in the writing styles of contributors, but nothing is going to change unless actual examples are brought to attention.

...R