💬 Arduino Pro Mini Shield for RFM69(H)W

[gohan]

read rfm69 datasheed, the pins can only take up to 3.6V, they are not 5V tolerant like the NF24

[pepson]

Yes
But i reduce power from 5V to 3,3V by AMS1117

[gohan]

I'm not talking about vcc, I'm talking about data pins

[scalz]

@pepson
if your arduino VCC is 5v, then arduino SPI lines are running at 5v and sending 5v to RFM69 SPI pins which is not ok. like gohan said, you need level shifter, or use a 3v arduino pro mini

[pepson]

i use it on arduino pro mini 5v and works ok. no problem. Also use RFM69HW on RPi3 and also works ok.
When i use on Arduino Pro Mini 5V i can not use RFM69HW with AMS1117 ? Radio will be destroy after some times ?

[pepson]

Also on mysensors show how connect it to Arduino 5V
https://www.mysensors.org/build/connect_radio

[zboblamont]

@pepson "NOTE: The NSS, MOSI and SCK are not 5V tolerant on RFM69. You will need to use a level converter if you're using a 5V Arduino."....

[pepson]

Ok but why nothing is describe on MySensors on page where show how connect radio ?
But i have connected and works ok 5V without logic level converter...

If i not use this logic level converter what will be happen ?
I can use this https://pl.aliexpress.com/item/8CH-IIC-I2C-Logic-Level-Converter-Bi-Directional-Module-DC-DC-5V-to-3-3V-Setp/32238089139.html?spm=a2g17.search0104.3.299.voV8Dr&ws_ab_test=searchweb0_0,searchweb201602_4_10152_5000015_10151_10065_10344_10068_10342_10343_51102_10340_10341_5130015_10084_10083_10304_10307_10301_10312_10059_10313_10314_10534_5790011_100031_10604_10103_10594_5060015_10142,searchweb201603_32,ppcSwitch_4&algo_expid=1efe59eb-1872-47dd-8d87-8a30137c624f-24&algo_pvid=1efe59eb-1872-47dd-8d87-8a30137c624f&rmStoreLevelAB=5 ?

[scalz]

@pepson
You're messing things, you should recheck.
zboblamont extracted the note exactly from here https://www.mysensors.org/build/connect_radio
If you check the rfm69 section, then you'll see it's not 5v tolerant. You can also check min and max input voltage in rfm69 datasheet if you need.
In the above link, it is not mentioned that it is using a 5v arduino (i agree the regulator on the pic can be misleading, but there is the note..).As there is no level shifter on the pic, you should consider it as 3v arduino with use of additional regulator in case the arduino is not beefy enough for the radio module.. :)

On your rpi, do you connect the rfm69 vcc to 5v rpi? I don't think so, or you'll fry your radio.. And the Rpi GPIO are 3v, not 5v. So no problem for the radio spi.

3v arduino mini pro has a regulator to convert 5v input to 3v for atmel. So on these boards, the atmel vcc is 3v, and signals too. To not mess with 5v arduinos, which are running full 5v.

I guess these level shifter should work, I have no xp with these. And generally prefer to go simpler, without levelshifting.

[pepson]

ok but for arduino pro mini 3v i can not connect relay 5v. I use it to control relay...
Can i use it : https://pl.aliexpress.com/item/8CH-IIC-I2C-Logic-Level-Converter-Bi-Directional-Module-DC-DC-5V-to-3-3V-Setp/32238089139.html?spm=a2g17.search0104.3.299.voV8Dr&ws_ab_test=searchweb0_0,searchweb201602_4_10152_5000015_10151_10065_10344_10068_10342_10343_51102_10340_10341_5130015_10084_10083_10304_10307_10301_10312_10059_10313_10314_10534_5790011_100031_10604_10103_10594_5060015_10142,searchweb201603_32,ppcSwitch_4&algo_expid=1efe59eb-1872-47dd-8d87-8a30137c624f-24&algo_pvid=1efe59eb-1872-47dd-8d87-8a30137c624f&rmStoreLevelAB=5

[zboblamont]

@pepson I suggest you read it again.... The table refers to VCC 3.3v, thereby what is shown NOT a 5v device, the NOTE on that page and which I quoted above spells it out clearly, a converter would be required for 5v.
If you are supplying it with 5v as well as connecting 5v logic, it is working outside it's specifications, that it is working at all is luck, but magic smoke will appear at some point.

[pepson]

To VCC i put 3.3V (by AMS1117)
All other pins from Arduino i use directly.

[scalz]

@pepson
let's recap, I'm not sure you got it..
Says you have a VIN of 5 or 9V, and you connect it to your arduino. On the arduino board you have a ldo. So:

• 5V Arduino variants will convert the VIN to a 5V VCC supply to you microcontroller (let's call it atmel, or 328p it's shorter). At this moment the atmel is running fully on 5v. If you set an IO to HIGH or =1, it will output 5V! And it's the same for SPI that you connect to your radio module. You thought you could apply a lower voltage to the radio module by applying an external 3V ?? Can't work, because SPI has datain and dataout. Dataout from atmel to radio will be 5v!!
• 3V arduino variants will convert your VIN (5, 9V etc..) to 3v. The atmel will run on 3v, its pins and peripherals too, so no problem for the dataout above.

I can't explain better, or maybe you should use a 3v arduino, and add a fet to drive your relay from 5v.
I would prefer this way (level shifting a basic io, than level shifting the spi bus)

[zboblamont]

@pepson This reminds of that famous quotation "Any ship can be a Minesweeper..."
"Once...."

[gohan]

@pepson if you need to run a relay, just get an optoisolated relay board and you can use a 3.3v arduino or raspberry without problems.

[pepson]

@scalz
What is "fet" ?

When i use Arduino Pro Mini 3V i can put power 5V to Arduino and he step down to 3V ? Arduino will not destroy ?

[pepson]

@gohan said in 💬 Arduino Pro Mini Shield for RFM69(H)W:

@pepson if you need to run a relay, just get an optoisolated relay board and you can use a 3.3v arduino or raspberry without problems.

I dont uderstand ?
Relay is power by 5V. But if i use Arduino Pro Mini 3V he give to relay 3V and relay probably not working on power 3V...
Sorry i am beginner...

And i can use this logic level converter

https://pl.aliexpress.com/item/8CH-IIC-I2C-Logic-Level-Converter-Bi-Directional-Module-DC-DC-5V-to-3-3V-Setp/32238089139.html?spm=a2g17.search0104.3.299.voV8Dr&ws_ab_test=searchweb0_0,searchweb201602_4_10152_5000015_10151_10065_10344_10068_10342_10343_51102_10340_10341_5130015_10084_10083_10304_10307_10301_10312_10059_10313_10314_10534_5790011_100031_10604_10103_10594_5060015_10142,searchweb201603_32,ppcSwitch_4&algo_expid=1efe59eb-1872-47dd-8d87-8a30137c624f-24&algo_pvid=1efe59eb-1872-47dd-8d87-8a30137c624f&rmStoreLevelAB=5

??

[gohan]

Get one of these and you can use whatever arduino you want
https://www.aliexpress.com/item/With-Optocoupler-4-Channel-4-channel-Relay-Modules-Relay-Control-Panel-PLC-Relay-5V-Four-Way/32458001101.html

And maybe a new rfm69 module since you probably already killed the one you used.

[pepson]

@gohan

Radio works ok.

But from where i get 5V for Relay ?

[gohan]

@pepson if you have the 5V power supply, you get it from there