ESP8266 Distance Testing

With progress slowly being made on turning the ESP8266 UART to WiFi module into something great, there is still the question of what the range is for the radio in this tiny IoT wonder. [CNLohr] has some test results for you, and the results are surprisingly good.

Connecting to the WiFi module through a TPLink WR841N router, [CN] as able to ping the module at 479 meters with a huge rubber duck antenna soldered on, or 366 meters with the PCB antenna. Wanting to test out the maximum range, [CN] and his friends dug out a Ubiquiti M2 dish and were able to drive 4.28 kilometers away from the module and still ping it.

Using a dish and a rubber duck antenna is an exercise in excess, though: no one is going to use a dish for an Internet of Things thing, but if you want to carry this experiment to its logical conclusion, there’s no reason to think an ESP8266 won’t connect, so long as you have line of sight and a huge antenna.

There’s still a lot of work to be done on this module. It’s capable of running custom code, and since you can pick this module up for less than $5 USD, it’s an interesting platform for whatever WiFi project you have in mind.

41 thoughts on “ESP8266 Distance Testing

          1. For 5km omnidirectional, WiFi is probably the wrong tech for your needs, though it can be made to work for point to point directional connections. Zigbee might work for you if you want long distance but low speed. 4G/LTE/WiMax might be more what you want for high speed/long distance, but you likely won’t find any low cost modules.
            I don’t know the physics either so for take that for what it’s worth.

          2. You might try looking into amateur radio. 5km is nothing on the ham bands. I’ve sent data over 18,000km using a 3 watt signal in the 20 meter (14 MHz) band.

            You might not find precisely what you are looking for, but then you just might. Or you might discover a whole new world of fun things to do.

        1. The problem with long-distance omnidirectional communications is that all radio spectrum is shared. To get 5km requires enough power that you’ll be stepping on other spectrum users, and any laws that are there to prevent that kind of thing. Some options:

          1) The central node can use an omnidirectional antenna, if all other nodes use highly directional antennae.
          2) [Kenneth] mentioned getting an amateur radio license and using AX.25. I’m not familiar with that. But if that is a possible option, I’d look into any specific rules. You still have to play nice and share spectrum, so there are probably limitations to how long or often you can transmit, identification requirements (broadcasting callsign), etc.
          3) Use cellular data modems. Of course you’ll have to pay service fees.
          4) Use old tech. Especially stuff that works at lower frequencies, since they penetrate obstacles better and therefore carry farther than 2.4Ghz (which is mighty crowded as well). For example, I have pair of Metricom Ricochet Wireless Modems. IIRC they broadcast 1W in the 900mhz range, and have a 115.2kps serial interface with AT command set. Supposedly can reach up to one mile under ideal conditions, without any mods – which is at least closer to your goal.

    1. I’ve used Ubiquiti NanoBridges for 6km hops, and they didn’t even break a sweat. The problem is an antenna one; you won’t get 5km with omni antennas, and can go that far using just about any WiFi module with a directional antenna connected.

          1. AX.25 is another option. 1200 bps, but I use it 30 miles with an omni antenna. The one major problem is that you need to get an amateur radio license for it…

    2. I’ve gotten 8 miles line of sight from a 24dBi grid antenna pointed at an 11dBi omni at 2.4GHz using standard Atheros 802.11abg radios running at 27dB output. The omni was at about 180 foot elevation with the grid at about 40 foot elevation in relation to the surrounding terrain.

      I’ve also gotten 25 miles line of sight using two 32dB 5GHz parabolic dishes using standard Atheros 802.11abg radios at 27dB output. Both of these dishes were at about 180 foot elevation in relation to the surrounding terrain.

      Both setups would give me about 25mbps full-duplex or over 45mbps half-duplex.

      At greater distances one should take extra care to set the Acknowledge Timeout appropriately…

        1. There are a number of things that seem to be able to cause that. It has done that randomly once to me, too, but, I hit reboot and it linked right up. If you try doing other things, or you tell it to connect in the wrong mode, it will do all sorts of bizarre things.

          (I did forget about the AT+CWMODE setting) (which it seems you have to reboot after issuing)

  1. The title says testing Range of the module, when in fact the discussion is all abot directional / antenna patterns. (started by soldering on a rubber duck,etc.) Greay primer on antenna patterns. That’s all.

  2. I first wondered why you can (legally) get these high ranges, but then realized why:
    You lucky Americans – in 2.4GHz you can legally transmit with +30dBm = 1W (PA) and then still attach a 6dBi Antenna.
    And at +22dBm you can even use a 30dBi antenna for total 52dBm, is that right?

    Crazy… in Europe we are only allowed to go up to +20dBm = 0.1W total (PA+Antenna)…
    Well – on the other hand maybe it is better this way, otherwise in medium sized cities you won’t get a working private WIFI network if just any retard could attach 30dBi Antennas to all his crap-gadgets ;-)

  3. Just pondering how amazing this is, that even in the 1980s, this would’ve been maybe a cabinet worth of hardware. Or at least a big suitcase, with lots of big PCBs densely populated. 2-layer PCBs at that, with ribbon cables flying everywhere, and a separate lead-acid battery that might last an hour. You wouldn’t ask the price because it’d only be something for a company budget.

    Living in the future’s amazing. If the lazy sods would just get on with the flying cars it’d be fantastic.

  4. This module seems just the right choice for making voip multicast enabled helmets for bikers/paintball/etc. so that anyone talks and listens to anyone. Mesh networking, if doable, would extend the range because any “station” would work also as a repeater for those that cannot reach each other.

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