E220 with Arduino Pro Micro and Step-down DC converter

Hi!

I’m new to E220 and trying to work with it using Arduino Pro Micro (5V). I’ve made connections as instructed here, but since Arduino Pro Micro doesn’t have 3.3V output and I have few spare DC-DC step-down 3.3V converters, I added one to convert 5V to 3.3V (also instead of using 2k and 1k resistors, I used 1.8k and 3.6k which I found my storage box).

Unfortunately it seems that it doesn’t work, error (12 – no response from device) is shown. When using the same E220 device with my another Arduino Pro Mini (3.3V) with more simpler connections, everything works smoothly. I’ve checked the connections and everything should be fine based on my understanding.

Here’s the full trace:

”
No response from device! (Check wiring)
12
—————————————-
HEAD : 0 0 78

AddH : 65
AddL : 64

Chan : 114 -> 524MHz

SpeedParityBit : 0 -> 8N1 (Default)
SpeedUARTDatte : 1 -> 2400bps
SpeedAirDataRate : 0 -> 2.4kbps

OptionSubPacketSett: 1 -> 128bytes
OptionTranPower : 0 -> 22dBm (Default)
OptionRSSIAmbientNo: 1 -> Enabled

TransModeWORPeriod : 1 -> 1000ms
TransModeEnableLBT : 0 -> Disabled (default)
TransModeEnableRSSI: 0 -> Disabled (default)
TransModeFixedTrans: 1 -> Fixed transmission (first three bytes can be used as high/low address and channel)
—————————————-
Hi, I’m going to send message!
Success
”

Is there possibility to debug what might be the problem? Or do you think that this step-down converter is for some reason anyhow bad idea?

Here’s image of the connections if it helps anyhow.

Thanks a lot for the help in advance!