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The WiFi Link
Important
If you have a motor attached to the board when making changes - BE VERY CAREFUL. In order to save parameters the motor has to be stopped. Stopping the motor quickly using the slider can generate a very high voltage that can destroy the WiFi Link, connector cable and possibly the board.
The simple fixes are:
- Disable the complementary PWM to allow the motor to coast when it's stopped - but this is probably not a desirable permanent setting and it’s a catch 22, you need to attach and save the setting first.
- Disconnect the motor from the board.
- Put a “clamp” on the power supplied to the board. We have designed a simple clamp circuit, we have only a couple left for sale on https://aart.dev The KiCad files to make one are in github.
This is a device that attaches to a Remora1 in order to allow you to change and save a Remora's configuration (parameters and software) by using a device that can connect to WiFi - such as your phone, a tablet or a computer. You'll only need one of these for all your Remoras.
The WiFi Link connects to the Remora using a very small cable. The cable provides power and signal to the WiFi Link from the Remora.
The cable is quite fragile and cannot carry a lot of power. We suspect that if you have a motor attached, the operation of the slider can cause a very high voltage to be returned from the motor when the slider is moved to the left causing possible damage to the WiFi link and perhaps the Remora.
There are a couple of different sources for the WiFi Link, namely:
- Buy one from us at https://aart.dev
- Make one yourself, by buying a ESP32 S2 mini, flashing it, and optionally, either buying or making the adapter shield.
- Buy an ESCape32 WiFi Dongle and obtain and solder on a connector cable to attach it to the Remora1.
- You'll need some sort of intelligent device that has 2.4GHz WiFi - such as a phone, tablet of computer. Turn it on and keep it close.
- Attach the WiFi Link to the Remora using the skinny four wire cable. There's a very small black socket on the top left side of the Remora (the one opposite to the +ve and -ve pads) about half way along. Make sure the cable is fully inserted into the socket.
- If the Remora is connected to a motor, it might be best to disconnect the gear or remove the wheels, because the motor will run.
- Apply about 7V, 1.5A to the Remora with the right polarity. If the Remora is in a car, use a pair of crocodile clips to apply the power to the braids. If the motor is attached and it does not start, turn off the power immediately and disconnect the motor from the Remora.
- The WiFi link will flash a blue led - once as power is applied.
- Open the WiFi settings in your intelligent device and connect to: ESCape32-WiFi-Link (there is no password)
- If your device hasn't opened a web browser at the URL: escape32.local then open a browser on the device and open the link escape32.local
- It will open a three tabbed display like these: screenshots
- Use the first tab to change the settings.
- Use the third tab to update the firmware.
The latest WiFi links come in a 3D-printed enclosure, it's quite usable without one. If you'd like one, you can buy one from us at https://aart.dev, or make some yourself. The STL files to print them are in the git repo - JLCPCB's 3D printing service can help.
If you look very closely at the Remora you'll see a very small .6mm, 4 pin JST connector socket on the top of the board. This exports 4 connections, looking down from the top as it is inserted into the socket on the Remora1:
- PA15 (mcu signal): pin 1 (far left).
- PA2 (mcu signal): pin 2 (second from the left).
- VIN (+ve power from the eCom): pin 3 (third from the left).
- GND (-ve ground from the eComp): pin 4 (far right).
Hint: For details - look at page 3 of the KiCad schematic - top right J1.
The connector cable we supply is correctly wired to connect this socket on the Remora1 to the WiFi link and you'll notice one of the signal wires is deliberately crossed over.
If you choose to use the ESCape32 WiFi Link Dongle, you'll need to cut off one end of the connector cable, carefully strip a couple of millimeters of insulation off the wires and then solder them on to the corresponding pins on the dongle.
The WiFi link attaches to a Remora1 by a very fine four wire cable terminated by very small (.6mm) JST connectors. The connector socket on the Remora1 is a small black part located on the top left side of the Remora1. The other end of the cable plugs into a similar socket on a voltage regulator card on our WiFi link which is mounted on an "off-the-shelf" ESP32 S2 mini board.
It's very easy to break the cable and its connector socket - we are working on a better solution. You can replace the cable by buying one from an electronics parts supplier, or ask us for one - it's a standard part. To make it easier to insert and remove the connector into the board, we have found that a very small crocodile clip with one end bent over, makes the task simpler and less error prone.
Before you start remove power to the Remora1 (and if possible do not attach the motor). Do not attach the WiFi link with power on. Do not apply power to the WiFi link using the USB-C connector.
Assuming the cable is already attached to the WiFi link adapter. Plug the free end of cable into the Remora1 connector on the top left side of the board. Do it slowly and carefully. Unless you have good eyesight consider using magnifier glasses - at least until you have repeated the process a couple of times. Also, it'll be hard to insert and remove it the first few times you do it, and you might consider lubricating it with an extremely small amount of contact or silicon lubricant. The socket on the Remora1 is fragile and using too much force can run the risk of breaking the socket off the board.
Make sure the wire connector is orientated correctly, with the copper lead wires into the connector exposed in the connector on the bottom, and the very tiny moulded friction clip on the top. Ease the connector into the socket on the board and gently squeeze it in until it is fully inserted - it clicks in.
Apply about 7 volts, with at least 2 - 3 amps of current available from the power supply, to the Remora1. If you do not limit the current and the motor draws more than about 3 amps you run the risk of the cable getting very hot and self destructing. It’s possible to apply up to 18V for a short period without causing damage - but that's just silly and very dangerous (at high voltages we’ve seen motors quite literally explode, throwing bits of the rotor out like shrapnel).
If there is a motor attached to the Remora1 it will rotate, so be ready by keeping the car's wheels out of contact with a surface, or removing the gear. Hint: Once you've figured out the WiFi link user interface, use the slider at the bottom to stop the motor by sliding it right then left to stop the motor.
The WiFi link will flash a blue led to show it has power. Wait a minute or so for the WiFi Link to initialize - be patient.
In order to use the WiFi link, you'll need a computing device like a laptop computer or smart phone that has 2.4GHz WiFi capability.
Open the WiFi settings in the device and look for WiFi networks. You need to look for one named: ESCape32-WiFi-Link
Connect to it. It does not require a password. A note: your WiFi link and everyone else's have the same identifier, we haven't tested several WiFi links located close together to see how they behave, the range of the ESP32 S2 WiFi radio is small and hence access will be very localized. However, we suggest you make changes away from others who might be doing the same :-)
The WiFi link only allows one client to connect at a time, (first come first served) and it does reboot the Remora, which causes it to lose power from the Remora and have to restart, which kills the WiFi connection. Most WiFi clients have a "auto join" option which will cause the client to reconnect. This can result in some strange and unexpected behavior that seems like a connected motor is pulsing.
Depending on you device's software you may or may not be immediately redirected to a browser page at the link: http://escape32.local It should look like these screenshots.
If you are not redirected, open at browser at this URL. Hint: it might be a good idea to keep this link in your browser's "bookmarks." Also note, modern browsers prefer to make secure connections using the https protocol rather than the http protocol and will a give a security warning that can be ignored.
Modern browsers do not like connecting to insecure, http sites, and it's possible your browser will at first object to connecting to the WiFi Link. If you are using Chrome try changing the permissions by either clicking on the icon to the left of the URL in the browser or using this link to change permissions: chrome://settings/content/siteDetails?site=https%3A%2F%2Fescape32.local
If the WiFi link is connected properly, the blue led on the device will flash, and after a few seconds you'll get a tabbed display in the browser, which will allow you to change parameters and update the firmware. Be patient, it can take several seconds.
You’ll notice that the settings in the first tab are ones that are baked in to the firmware. All of these can be changed - only some of them are relevant.
To change a value - enter the new value. Then scroll to the bottom of the screen and slide the slider to the right than the left before pressing SAVE.
Be patient :-) your first attempt might be frustrating.
Make sure you've connected power to the Remora and the polarity is correct, and the Remora and WiFi link are connected using the cable.
Do not apply any power to the WiFi link itself using a USB cable!
If the SSID does not appear in your available WiFi access points on you device, then remove the power from the eCom (or slot car) and check the JST cables are properly inserted. They are very small and sometimes it takes a couple of attempts to make sure they are properly located in the socket. When you apply power make sure the blue led on the WiFi Link flashes.
It's also possible that the cable has broken, or the little socket on the WiFi Link adapter or on the eCom itself have broken off their solder pads - they are all very delicate and easy to break. If you need another cable try the links here: https://github.com/aartech-dev/slot-car-ecom/wiki/The-Connector-Cable If you need a new adapter or eCom try: https://www.aart.dev/
Make sure you are supplying enough power to the eCom and in turn the WiFi link. The WiFi link's radio needs at least an amp - check your power supply is capable of supplying this current and is not restricted. If you have the eCom, motor and WiFi link attached - make sure you have say 3A or more available. Also it's import to provide about 7V, again to power the eCom (and motor if it's attached). The WiFi link needs 3.3V, but can tolerate a lot more due to the adapter circuit which will protect the board from higher voltages.
If the browser page displays and advises you to reboot - ignore it, just give it a bit more time to initialize and refresh the page.
If the browser display does not refresh, try forcibly refreshing the browser.
If the device and the Remora seem like they are "pulsing" or continually rebooting make sure you do not have more than one web page open to the WiFi link's URL, namely http://escape32.local. If you have the link open in more than one tab or browser it'll cause it to repetitively reboot.
Again - if things behave badly - suspect the socket on either the adapter or eCom have bad connections to the board. If a power connection fails - there's no blue led on the board; if a signal connection fails - there'll be no browser output. They are fragile, and it's possible that they were not properly soldered to the boards in the manufacturing process, or the cable has broken or the cable connector has failed. Ask us for a replacement ...
We've also had reports that updating firmware from a browser has issues. One thing that can happen is the browser will not open the bin files from a folder on the device. If this occurs try updating your browser, or using a different browser on the device - Safari works on my iPhone, and Chrome is fine on a Mac and Linux machine.
The easiest and safest way to remove the connector from the socket on the board is to use a 2mm crocodile clip with one end bent over at 90º. We should have provided you with one if you bought a WiFi Link from us. It's also helpful to have a slightly long thumbnail if you don't have a crocodile clip.
Open the clip, and carefully clasp the top of the tiny bit of the protruding plug with the bent down portion of the clip and apply a small amount of pressure to the plug. This pressure will press down on a portion of the connector that locates in the socket and will release it. Then carefully pull the plug out.
When you use the slider at the bottom of the WiFi Web page to stop the motor in order to save settings it stops the motor quickly.
If you are connected say to a relatively low speed 3,000Kv motor using say 4V, the regenerated energy (braking power from the motor) raises the power voltage to 10V(!).
Kinetic energy is proportional to speed squared so it's easy to see how a faster motor and perhaps a higher supply voltage could easily exceed the safe voltage of the WiFi Link and indeed the Remora (~18V).
We think this is because the WiFi link is designed for running motors from a battery. It’s probably quite acceptable behaviour if you are running off a battery as the power supply, as there is somewhere for the energy from the motor to go. However the issue with power supplies is that they only work to source current, and they do not accept current coming back to them while keeping the voltage correct.
We’re are investigating this and hope to be able fix the issue by letting the motor coast to stop instead of making a rapid stop, this should prevent the regeneration, and stop the damage.
Copyright © 2025. All rights reserved Adrian Blakey