Transmission Range

[rbaron]

Transmission Range

[SystemFuchs]

Hi there,

due to the shortage for the chosen E73-2G4M08S1C module I opted for the following version with an external Ibex antenna socket (all other specs are identical) :

E73-2G4M08S1CX

I've ordered the following IBEX Antenna for 2.4G which can be easly put through the cover version with the hole.

Assembled it a few minutes ago & the range seems to be massive improved. Got a signal from the 1st floor to the ESP32 in the basement. Placed two of the sensors in our glasshouse in the garden & signal reception is fine (ca. 15m from the glasshouse to the ESP32) :-) Btw have to water the tomato this evening :-D Thx a lot for this beautiful project & all the effort which was put into it. Still have to solder 13 E73 chips on the remaining boards but really love it!

[mjeanrichard]

Cool, thanks for that input. For those who already have the module with the chip antenna, it can easily be desoldered and replaced with a piece of copper wire. I went with quarter wave and it works way better (even bent, see picture). Will do the same with the ESP32 to check if it improves further...

@SystemFuchs Did you by any change measure the power consumption with this antenna? I would assume it stays the same, but would like some data...

[rbaron]

That's awesome. Thanks for sharing @SystemFuchs.

[rbaron]

Hi @mjeanrichard,

I'm glad to hear they're working (consider contributing to your community gallery #19!).

There are three params you can tweak in prst_config.h:

• PRST_BLE_ADV_TX_POWER (already set to max by default)
• PRST_BLE_ADV_TIME_IN_MS - the amount of time it spends advertising (repeating the same advertisement). Set to 1 second by default
• PRST_BLE_ADV_INTERVAL_IN_MS - the interval between two consecutive advertisement packets (30 ms by default)

These last two params are mostly optimized for power efficiency. I have increased both for a couple of my b-parasites and observed some extra range (at cost of shorter battery life), but I also opted for having two bridges instead of just one.
Let us know if you manage to experiment with those params.

[mjeanrichard]

Ok, thanks for the suggestions. I will try to fiddle with the parameters.

What is the range you get out of yours?

[rbaron]

I haven't measured the range more precisely. I have two ESPHome bridges and they cover my whole apartment. It would be nice to collect some data against those params.

[mjeanrichard]

My insights after a some testing and trials:

• Enabling Bluetooth 5 Long Range might help (no exact measurements yet)
• Some other optimizations in code might help as well
• Removing the Chip Antenna and soldering a wire with the appropriate length make a HUGE difference

I'll follow up with some measurement (power consumption and range).

[rbaron]

@mjeanrichard I've been meaning to experiment with Coded PHY for a while. I added a new flag PRST_BLE_EXPERIMENTAL_LONG_RANGE that will switch the advertising PHY to use Coded PHY.

I only had time to run a quick test:

• In one b-parasite, I set PRST_BLE_EXPERIMENTAL_LONG_RANGE to 1
• On a different b-parasite, I hacked together a Coded PHY scanner based on the Coded PHY central from nRF Connect

It looks promising and I think this is worth pursuing. Hopefully you can use this flag in the tests you're running.

I'm interested in if/how can we implement Coded PHY scanning in ESPHome. Right now I don't think it's possible, but they do already support ESP32-C3/S3, which I believe are Bluetooth 5 capable and can do Coded PHY.

[SystemFuchs]

Cool, thanks for that input. For those who already have the module with the chip antenna, it can easily be desoldered and replaced with a piece of copper wire. I went with quarter wave and it works way better (even bent, see picture). Will do the same with the ESP32 to check if it improves further...

@SystemFuchs Did you by any change measure the power consumption with this antenna? I would assume it stays the same, but would like some data...

Hi @mjeanrichard,

didn't do any measurements until now. How can I measure the power consumption of a parasite?

[Hedda]

For those who already have the module with the chip antenna, it can easily be desoldered and replaced with a piece of copper wire.

Tip! With it using 2.4GHz you should normally make such monopole antenna length ~ 31.23mm long unless you know that the firmware is tuned for an antenna non-standard 2.4GHz length, and preferably use a 1mm diameter wire.

Recommend search on Google for "Monopole Antenna Calculator" (and "Dipole Antenna Calculator" if prefer such an antenna design instead)

[RobertLukan]

I have replaced the ceramic antenna with monopole 31mm long wire(1mm diameter) and there is a significant improvement. I could notice about 20-25 dB improvement. I am not sure how to measure the power consumption, but I guess it should be the same as I have not changed anything else. Thanks for the tip.