How to update RFID-Sensor

If you have a ready-built or DIY-version of RFID-Sensor and use batteries with more than 8192mAh capacity you need to update your sensor. This is due unfortunate bug found in sensor software not showing larger values correctly. All new RFID-Sensors shipped have always the most recent firmware inside. Version 2.1 and up of sensor firmware has this bug fixed.

If you are using only batteries with less than 8192 capacity you do not need to do anything!

Now, this might look complicated but actually is not, take your time and it’ll be fine. In fact might be a good thing to learn this, there might come some new functions to sensor later anyway.

NOTE: before doing this write down cycles on your tags. You need to rewrite all tags, unfortunately. This is due changed memory allocation on tag for Robbe BID2NFC compatibility.

What you need

You need a sharp hobby-knife, USB-TTL cable and the sensor of course. Also a toothpick is recommended.

Preparation of sensor

Take the sharp knife and carefully open a “hatch” to get to the Arduino programming header:

The orientation of programming cable’s pins are according picture below, from top GND, VCC, TX and RX:

Put a strip of 4 header pins as in picture above to the cable and simply put it in the holes of Arduino programming header:

Before doing any updates from PC let’s prepare and look for location of Arduino reset-button. It’s located on the cable-end of sensor, there is a hole in the middle PCB for easier access. Do not use screwdriver or anything metallic when pressing the button just in case you might short something. There is no dangerous voltages or currents in there but electronics just do not like to get shorted. So, use the toothpick.

Ok, let’s get on the software.

Download the update and XLoader

Go to my github here and press the green “clone or download”-button. Extract the zip-file and go into Arduino\BatteryRFID folder, you will find a file BatteryRFID.hex there. (51KB in size)

You do not need to install the Arduino IDE, any libraries etc. All you need is the XLoader app from my server here (Exactly the same as in authors page here, only exception is the device-list, I added Jeti-sensor)

Unpack the and run the XLoader.exe, you are presented with small app:

Point the “Hex file” to the BatteryRFID.hex you downloaded from my github, select Device to “Jeti-Sensor”, make sure you have your TTL-adapters com-port selected and it looks like this:

Now comes the tricky part. You need to hold the programming cables headers on the Arduino so they do not move and have a good contact, a little pressure is ok. Then hold the sensors Arduino reset button pressed with the toothpick, now press XLoaders “Upload” button. As soon as you see the “Uploading…” text in bottom of XLoader-app release the reset-button in your sensors Arduino:

After successful loading XLoader tells you how many bytes went into board:

That’s it, you’re done!

If you do not get in at first try just try again, might be a bit tricky at first.

What you also need to do

Unfortunately if you are using “RC-Thoughts tags” you need to re-do the writing of settings. This is due changed memory-place on tags memmory for BID2NFC compatibility.


Now you can use batteries with capacity up to 65535mAh and have them displayed correctly:

Sorry for any possible inconvenience this small issue might have brought you.

Have a nice day!

One thought on “How to update RFID-Sensor

  1. Hello Tero,

    how can I update the sensor I bought from you. There is no connector included, where I can connect the USB-device to.

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