Quote:If there are any problems you are running into, what are they ? What are you motivating the idea with ?
tcm3105 wrote:Easiest solution: ESP-Link
Quote:The esp-link firmware connects the microcontroller to the Internet via the ESP8266 Wi-Fi module. It implements a number of functions:
JacekCz wrote:As with everything in IT "it depends" ...Serial works at byte level, networks at packet level....
globalinfo wrote:I would like to be able to connect e.g. a laptop via USB and communicate remotely without having to stand at the device.
globalinfo wrote:JacekCz wrote:As with everything in IT "it depends"
...Serial works at byte level, networks at packet level....
And maybe Bluetooth would be better?
xury wrote:You can and in many ways. It is very simple e.g.:
https://github.com/yuri-rage/ESP-Now-Serial-Bridge ....
#define BOARD1 // BOARD1 or BOARD2
#define RECVR_MAC {0x94, 0xB9, 0x7E, 0x**, 0x**, 0x**}
Quote:
ESP32 MAC Address: 94: B9: 7E: **: **:**
0
Quote:Set the IP address of the OPPOSITE board as the RECVR_MAC value in the macros at the top of the sketch.
xury wrote:I understood it like this
You define one as BOARD1 and the other as BOARD2
You enter MAC addresses (not IPs as described probably incorrectly) alternately. So in BOARD1 you enter the MAC from BOARD2 and in the other one vice versa.
margas60 wrote:Describe how you did it because I'm trying to do the same thing and it came out a mess.
This arduino environment is twisted somehow.
I have an ESP8266 and a RS232 converter board.
#include
#include
#include
where to take this from and how to add it to the program?.
margas60 wrote:Nothing works Arduino is some kind of monster where you don't know what to do. It doesn't open *.h files downloaded from Github, when you make a new one and paste the code it saves some *.imo .... what is this ?. I used to write in normal environments for C and this is Arduino ? ... ... nor upload anything, it saves you don't know what, not to mention how to compile it and then upload it to ESP .... sorry I guess I'm too old for this.
margas60 wrote:I fought, fought ....... and fell .... I don't know what I'm doing wrong ..... the program on the ESP [via www] is running, it can be reconfigured but there is NO communication with the program on the laptop. I think I will drill through the walls and will try to figure out how to run the cable ..... but still some section will be underfoot ....
margas60 wrote:Well, once again the INVERTER sends data over RS232 so by design I let it into the ESP after setting the IP address of my LAN. Now this data is received via WIFI by a laptop on which the inverter monitoring software is installed, in which I set the IP given to the ESP. The software processes the data and displays .......... unfortunately the ESP does not send any data, so either the configuration or it simply will not work like that.
I also have a module EW10A in a similar configuration panel designed for RS232 transmission via wifi, but it is quite messed up in the head because once it is accessed by IP and after a while no longer, but in the network is visible, transmission also failed to start.
TL;DR: For an 8 m link through two walls, two ESP32 boards using ESP-NOW solved remote RS232/RS485-style access; after setup, the user reported it worked for 2 days with no issues, and one reply summed it up: "It works great both ways." This FAQ is for anyone who wants a laptop-to-device wireless serial bridge without running a cable. [#21011771]
Why this matters: It shows when a simple two-board wireless serial bridge can replace a short private cable run, and when protocol, delay, or software expectations can still break the design.
| Approach | Hardware mentioned | Best fit in the thread | Main limitation noted |
|---|---|---|---|
| ESP-Link | ESP8266 in its description | Simple serial-over-Wi-Fi idea | Documentation cited by the user mentions ESP8266, not ESP32 |
| ESP-Now-Serial-Bridge | 2× ESP32 | Short transparent serial link through walls | Needs both boards configured with opposite MAC addresses |
| ESP32 UART bridge | ESP32 | Wi-Fi UART bridging to TCP/network tools | Packet-based networking can affect byte-stream behavior |
| Modbus RTU to TCP bridge | ESP32 + Node-RED workflow | When the target already speaks Modbus | Not a transparent replacement for every serial app |
Key insight: The thread’s successful design did not use one ESP32 as a universal serial-to-Wi-Fi drop-in. It used two ESP32 boards, one on each side, and matched the inverter’s 9600 baud link.
BOARD1 and the other as BOARD2. 3. In each sketch, place the other board’s MAC address in RECVR_MAC, so each ESP32 points to its partner. That mirror setup was the fix that made the bridge work both ways. [#21009054]RECVR_MAC tells each board which peer should receive its wireless packets. Put the opposite board’s 6-byte MAC address directly in the macro at the top of the sketch, for example under #define BOARD1 or #define BOARD2. The user was confused by a note mentioning IP, but the reply clarified that the sketch needed MAC addresses, not IPs. [#21009054]RECVR_MAC on each board. [#21008711]esp_now.h, WiFi.h, and esp_wifi.h, then asked where to get them. The working advice in the thread was to first run and test basic ESP-NOW programs on two ESP8266 boards before adding the serial side. [#21031735]