Strange behaviour with DC 3.3v step-up booster

[jumping]

Hello,
my "mysensors" nodes are based upon a modified version of Easy/Newbie PCB (https://www.mysensors.org/hardware/newbie-pcb).
The nodes work fine with battery supply but without the step-up booster,
when I use a 3,3v DC step-up booster, the transmission with the gateway fails:

Starting sensor (RNNNA-, 2.0.0)
TSM:INIT
TSM:RADIO:OK
TSM:FPAR
TSP:MSG:SEND 255-255-255-255 s=255,c=3,t=7,pt=0,l=0,sg=0,ft=0,st=bc:
TSM:FPAR
TSP:MSG:SEND 255-255-255-255 s=255,c=3,t=7,pt=0,l=0,sg=0,ft=0,st=bc:
TSM:FPAR
TSP:MSG:SEND 255-255-255-255 s=255,c=3,t=7,pt=0,l=0,sg=0,ft=0,st=bc:
TSM:FPAR
TSP:MSG:SEND 255-255-255-255 s=255,c=3,t=7,pt=0,l=0,sg=0,ft=0,st=bc:
!TSM:FPAR:FAIL
!TSM:FAILURE

Other info:

• 47uF capacitor beetween VCC and GND
• mysensors version is 2.0

Do you have any idea to solve the problem?
Thank you for your help!

[AWI]

@jumping step ups tend to make a lot of noise on the power lines (switching frequency) . Combined with the sensitive radio there is every reason to get into trouble.
A few possible remedies : a better quality step up. ; filter the power lines with a coil/capacitor or (better) include an LDO regulator ; get rid of the step up and use a lithium 3v battery.
I'm sure there is a lot of experience with the setup of this @sundberg84 board.

[sundberg84]

@jumping - I cant say it better than @AWI.

I have experienced this in a few nodes - and it was due to bad booster quality. I have had some success using a 0,1uF ceramic capacitor on the booster between out and gnd but sometimes its just not possible to get the noice away.
When i have ordered batches of 10 booster - its about 8 which is good and the other crap for different reasons (noice is one).

And just to confirm - you have only added the jumper on "BAT". If you have any other jumpers/connections that means the radio are getting its power from the booster which it should not. The radio should be feed directly from the battery for this reason.

[jumping]

Thanks for your answers!
I will try with a 0.1uF ceramic capacitor.

@sundberg84 yes, I only have added the jumper on "BAT"

[jumping]

Hello,
yesterday I added a 0,1uF capacitor between 3,3V and GND pins and I tried 8 different step-up booster without success!

In the next days I will try different configurations to understand what is happening!

[AWI]

@jumping Not to get you completely demotivated but there is some good (educated) reading in this article about noise suppression and why a simple capacitor doesn't work.

My personal (open to suggestions) preference is in using a 3v lithium cell (i.e. CR123, around €1 on aliexpress) which keeps a high voltage utill it's bitter end..

[jumping]

Hello @AWI thanks for you reply, I will read the document!

With other sensors I use LiOn Nokia/Samsung battery, and it's ok!
But I want to solve this little issue