Search found 27 matches

by humptydumpty
Mon Feb 25, 2019 10:03 am
Forum: ESP32 IDF
Topic: 802.11 error frame reception
Replies: 5
Views: 661

Re: 802.11 error frame reception

Thanks for asking. Would also be useful to be able to sniff for Bluetooth.

While I understand there are certification issues as far as radio transmission is concerned, I don't see why the radio functions have to be so undocumented on the reception side.
by humptydumpty
Fri Feb 15, 2019 11:09 pm
Forum: ESP32 IDF
Topic: ESP32 as Wlan Repeater
Replies: 5
Views: 6280

Re: ESP32 as Wlan Repeater

I have been able to receive UDP packets in promiscuous AP mode and then send them out again with esp_wifi_80211_tx() function. It is fairly easy if you limit it to a particular protocol. Probably it would be a lot of work if you wanted it to do more than that. And sending seems to be limited to abou...
by humptydumpty
Thu Feb 07, 2019 12:30 am
Forum: ESP32 IDF
Topic: 802.11 error frame reception
Replies: 5
Views: 661

Re: 802.11 error frame reception

I understand that 802.11 already has forward error correction. However, when the error correction fails for one or more blocks within a packet, the entire packet is discarded. Due to the highly repetitive nature of the data we are sending, it would be useful to receive the discarded packets. The rem...
by humptydumpty
Sun Feb 03, 2019 3:24 pm
Forum: ESP32 IDF
Topic: 802.11 error frame reception
Replies: 5
Views: 661

802.11 error frame reception

For a commercial application we need 802.11 error frame reception in promiscuous mode. Purpose is to implement Reed-Solomon-Code for error correction of broadcast packets. Is it possible?
by humptydumpty
Sun Feb 03, 2019 3:11 pm
Forum: General Discussion
Topic: Simple NAT implementation
Replies: 1
Views: 426

Re: Simple NAT implementation

I think you could just use the LWIP RAW API to forward the packets back and forth between ethernet and wifi interfaces. Just filter out the packets you don't need. You might need to change the IP address in the packet buffer as well. Shouldn't be too difficult once you figure out how to use the API.
by humptydumpty
Sun Jan 27, 2019 8:16 pm
Forum: ESP32 IDF
Topic: sending 802.11 data frame with esp_wifi_80211_tx()
Replies: 2
Views: 495

Re: sending 802.11 data frame with esp_wifi_80211_tx()

Answering my own question, in fact the esp_wifi_80211_tx function does automatically calculate FCS. My UDP packets were getting lost because I didn't calculate the IP header checksum correctly.
by humptydumpty
Sun Jan 27, 2019 8:13 pm
Forum: ESP32 IDF
Topic: esp_wifi_80211_tx in WIFI_MODE_NULL
Replies: 0
Views: 239

esp_wifi_80211_tx in WIFI_MODE_NULL

For our project we're using esp_wifi_80211_tx and promiscuous mode together. Basically we implement our own custom protocol. We don't want the unnecessary and redundant overhead of the Station and AP modes because we handle all the wifi packets in our own callbacks. But if we try using esp_wifi_8021...
by humptydumpty
Sat Jan 19, 2019 1:47 pm
Forum: ESP32 IDF
Topic: sending 802.11 data frame with esp_wifi_80211_tx()
Replies: 2
Views: 495

esp_wifi_80211_tx() and FCS

Maybe somebody can answer as to whether esp_wifi_80211_tx() generates the FCS or not. Actually I am having a problem with the FCS specifically. I use the ESP32 sniffer to capture frames and the FCS captured does not correspond to CRC of the payload. Therefore I don't know how to generate the FCS for...
by humptydumpty
Thu Jan 17, 2019 11:39 am
Forum: ESP32 IDF
Topic: sending 802.11 data frame with esp_wifi_80211_tx()
Replies: 2
Views: 495

sending 802.11 data frame with esp_wifi_80211_tx()

Hi, I wonder if anyone can post a complete example of sending an 802.11 data frame using the function esp_wifi_80211_tx . Although it appears I am successfully sending something, my wireshark captures don't indicate any data. Maybe there is a wrong checksum or something like that. Although there are...
by humptydumpty
Fri Nov 30, 2018 11:02 am
Forum: Hardware
Topic: Implementation of antenna diversity
Replies: 1
Views: 561

Implementation of antenna diversity

According to the ESP32 datasheet: • Antenna diversity ESP32 supports antenna diversity with an external RF switch. One or more GPIOs control the RF switch and selects the best antenna to minimize the effects of channel fading. However I can find no corresponding information in the technical referenc...

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