Firebeetle insuffiient wi-fi transmit power
nick.bower 2019-06-12 12:26:27 4627 Views8 Replies Hello. We have been having problems with Firebeetles unreliably sending network traffic when on wi-fi and some testing has highlighted a possible problem in the antenna design. See below for RSSI as measured by a Ubiquiti AP at 3 metres from a collection of various ESP32 boards. Please note that all of these RSSI results below from ESP-WROOM-32 chips are collected running the exact same firmware that we have under development.
DFRobot Fire Beetle 1 : -86
DFRobot Fire Beetle 2: -83
DFRobot mini ESP32 (PCB cut out below antenna): -72
Arducam ESP32: -47
Another ESP32 (white LORA board): -56
Another ESP32 PCB: -52
When extending the range to 15m and introducing some single brick walls,
Unmodified DFRobot Firebeetle 1 & 2: No association
DFRobot mini ESP32 (PCB cut out below antenna): -86
Arducam ESP32: -68
Another ESP32 (white LORA board): -72
Another ESP32 PCB: -69
The units if unmodified do not seem usable and the comparison shows that other ESP-WROOM-32 chips show a symmetrical RSSI (from device end and AP end), whereas the DFRobot design shows a significant asymmetry and degradation in TX power as seen from the AP.
We are experimenting with attaching a simple whip antenna as documented elsewhere but would like to hear DFRobot's view if these results are expected?
DFRobot Fire Beetle 1 : -86
DFRobot Fire Beetle 2: -83
DFRobot mini ESP32 (PCB cut out below antenna): -72
Arducam ESP32: -47
Another ESP32 (white LORA board): -56
Another ESP32 PCB: -52
When extending the range to 15m and introducing some single brick walls,
Unmodified DFRobot Firebeetle 1 & 2: No association
DFRobot mini ESP32 (PCB cut out below antenna): -86
Arducam ESP32: -68
Another ESP32 (white LORA board): -72
Another ESP32 PCB: -69
The units if unmodified do not seem usable and the comparison shows that other ESP-WROOM-32 chips show a symmetrical RSSI (from device end and AP end), whereas the DFRobot design shows a significant asymmetry and degradation in TX power as seen from the AP.
We are experimenting with attaching a simple whip antenna as documented elsewhere but would like to hear DFRobot's view if these results are expected?
2019-10-27 18:44:41 Dear all,
I have improved my ver 3 Firebeetle's extremely bad wi-fi performance considerably by carefully removing the PCB under the WROOM antenna. I used a Dremel grinding tool. RSSI improved from -70ish to -55, albeit still at close distance to the AP.
This was inspired by Daniel deBeer of EzSBC who in a blog post pointed out that "The ESP32 module is designed to have the antenna sit out in free space. The antenna is not supposed to sit on top of the PCB, the design guide by Espressif makes that very clear. The measurements that they did and documented show clearly that there is a significant loss in performance when the antenna sits on top of the PCB. The module’s PCB is much thinner than the standard 1.6mm PCB and they obviously designed the antenna for the thin pcb. User reviews of some of the other ESP32 boards on the market confirm that the ones where the module sits completely on top of the PCB have poor RF performance." hans.fahlin
I have improved my ver 3 Firebeetle's extremely bad wi-fi performance considerably by carefully removing the PCB under the WROOM antenna. I used a Dremel grinding tool. RSSI improved from -70ish to -55, albeit still at close distance to the AP.
This was inspired by Daniel deBeer of EzSBC who in a blog post pointed out that "The ESP32 module is designed to have the antenna sit out in free space. The antenna is not supposed to sit on top of the PCB, the design guide by Espressif makes that very clear. The measurements that they did and documented show clearly that there is a significant loss in performance when the antenna sits on top of the PCB. The module’s PCB is much thinner than the standard 1.6mm PCB and they obviously designed the antenna for the thin pcb. User reviews of some of the other ESP32 boards on the market confirm that the ones where the module sits completely on top of the PCB have poor RF performance."
hans.fahlin 2019-07-10 00:17:03 Same happened here, thought I my first Firebeetle ESP32 V3.0 had a broken wifi module and ordered a second one, but with the same result. Impossible to connect to a wifi network, tried with different access points. h.protzek
h.protzek 2019-06-15 01:46:17 I am experiencing extremely poor wifi on my Firebeetle ESP32 V3.0 as well. I ordered two other Firebeetles because I thought that something was broken with my first device. Both new Firebeetles show exactly the same poor wifi performance as the first board. I literally have to put the device right on top of my wifi router to make a successful connection. Move 20 cm away and no connection can be established anymore. I fear that this is a hardware issue :/ cl3m3ns
cl3m3ns 2019-06-14 14:27:08 76dB is slightly better but it is not usable for anything real. As I emailed your technical support I'm still waiting for real information on this.
- What is the exact cause?
- Do you have a fix now? If so, what is it?
- What can we do here to make our own fix while we wait for your fix? We would consider modifying our current units.
- How long before your fix ships to us in Australia? nick.bower
- What is the exact cause?
- Do you have a fix now? If so, what is it?
- What can we do here to make our own fix while we wait for your fix? We would consider modifying our current units.
- How long before your fix ships to us in Australia?
nick.bower 2019-06-13 22:41:34 Why do you say this?
It makes no difference anyway. Same test condition at 3m resulted in 76 dB. Still unusable. nick.bower
It makes no difference anyway. Same test condition at 3m resulted in 76 dB. Still unusable.
nick.bower 