ATtiny85 + RFM95 Temperature Sensor

End Devices (Nodes)
10

I think I found the solution with disabling the ADC ADCSRA &= ~(1<<ADEN);
in sleep mode saves about 235uA.
without sensor 5uA in sleep mode I am happy :yum:

And with the thermistor connected 153uA.

ttn

2 Likes
11

which bootloader do you use ?
will it work with v2.0 ?

why the bod @ 1v8 ?

12

I didn’t test with 2.0v yet and disabled the BOD for low power consumption.
Now I use this fuse settings -U lfuse:w:0x52:m -U hfuse:w:0xdf:m -U efuse:w:0xff:m
With the USBtinyISP for programming no bootloader is needed

2 Likes
13

Great example! thanks for share it will be so usefull for me, in this holidays i will work on a version which supports partially class c, wish me luck!

14

good luck :wink:

x565
some ATtiny85 eBay products

1 Like
15

I like the ATtiny programmer shield it looks ancient. :joy:

1 Like
16

Thanks for the extra effort of bitbanging all the low level stuff…

17

All credits go to Gerben den Hartog I only rearranged it a bit. :+1:

18

Sure … but It’s still nice to see a experimenal Lora version of the outdated Tiny TX concept from Nathan Chantrell…

19

I had succesfull working on this code to be used as class c, but the code i worked on was for an Arduino Pro Mini, now its time to port it to the Tinny if annyone needs somenthing like that for an arduino uno or pro mini i left the link to the gist.

I’m Working on the message decryption part right now but at least right now im receiving

Hope it be usefull!

I will keep working in this code, and create a repository but by now this is what i have :smiley:

2 Likes
20

It seems that you have a pin shortage on the ATtiny if you need DIO5 and you read from the RFM module.
SPI 4x (MISO,MOSI,SCK,SS) VCC, GND, DOI0,DIO5 that’s it nothing left for temp sensing.

1 Like
21

Yeah, i did it for an arduino mini pro, i needed to do a Class c node, now i will port it to an ATtinny.

22

After my earlier sketch of the ATtiny85 I packed everything in an easy-to-use Arduino library.
I made a step-by-step tutorial on the TTN Labs site, explaining everything from the installation up to the wiring.
I replaced the thermistor with a smarter sensor with SPI capabilities.
The Bosch BME280 can measure temperature, humidity and pressure.

4 Likes
23

Thanks for sharing.

My two cents: As you are not using hardware interrupt for DIO0, you can replace your digitalRead() by a read of RFM95 register 0x12 (RegIrqFlags) bit 3 (TxDone).

This can free one pin on your ATTiny.

1 Like
26

Sorry, should read more first. Got too excited by the concept. Great work!!

27


US $1.35 incl. shipping

28

I tried this one, thinking I could use it instead of the Arduino setup (since it says “Programmer Board”), but I needed to upload a bootloader to the ATTINY85 first.
I ended up using the Arduino setup to first load the bootloader (and then also the program since that was just as easy).

29

@jym This is a good idea that saves the effort for changing the Reset pin.

30

OK I thought to that you could use it to upload a bootloader :sunglasses:

31

Yeah, it is different for the ones with the ATtiny85 integrated into the board:

https://nl.aliexpress.com/item/Free-shipping-Digispark-kickstarter-miniature-for-Arduino-usb-development-board-with-pins-and-Anti-static-bag/32222311445.html

Those already have the bootloader installed and can be used straight away by just plugging them into USB (and install all the needed stuff in the Arduino IDE of course)>
In price they only add 20 cents to the chip, but they expect 5V instead of 3V.