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Sending adc data (wireless)

Posted: Sun Jun 17, 2018 4:24 am
by naalald
Hello,
I'm trying to get some analog data using adc channels (I'm using 8 channels) and then send it wireless and I think wifi is the best option since I need large data rate (> 2Msps). I've read the adc and wifi examples. But I'm not sure how exactly to send the values one by one. what is the exact function and port that sends the data through wifi.
Thank you.

Re: Sending adc data (wireless)

Posted: Sun Jun 17, 2018 2:03 pm
by fly135
There is a whole education about TCP/IP networking behind that question. Do you know anything about the POSIX socket api? The difference between a TCP server and client? The difference between reliable (TCP) and unreliable (UDP) network transmissions?

Because those are the sorts of things that you typically need to know to handle a project like this. And when you are sending there must be a receiver. Is that another ESP32, a computer, an HTTP server?

John A

Re: Sending adc data (wireless)

Posted: Sun Jun 17, 2018 11:53 pm
by hassan789
Setup a 40MHz wifi, on a quiet channel.. Ensure you have a very good RSSI (like -30dBm).... max out the TCP buffers. You should have more than enough throughput from you ESP to do this.

Re: Sending adc data (wireless)

Posted: Sun Jun 24, 2018 11:54 am
by naalald
Thanks for the answers.

Yes, I know about the stuff you mentioned except POSIX socket. It should be a reliable transmission and the receiver is another esp32. Since it's a one way connection the transmitter just sends the data and the receiver gets them. So, I can use

So, I've found two functions that can do this. One is free80211_send and the other one is esp_wifi_80211_tx. Which one is a better option? The first one just sends raw data and I think no wifi connection is needed. But the second one needs a wifi connection I guess.

How to max out TCP buffers?

Thank you.

Re: Sending adc data (wireless)

Posted: Sun Jun 24, 2018 12:49 pm
by naalald
How do you select the carrier frequency and the bandwidth of the wifi (e.g. you said 40 MHz)?

Re: Sending adc data (wireless)

Posted: Tue Jun 26, 2018 5:53 pm
by hassan789
I see... You are trying to cut out the middle man (the router), to get faster speeds.

I haven't done any raw 80211 frames, so you are already ahead of the game. If you can get it working, would love to see what results you get.