finding pin assignment for unknown beacon.

[Calin M]

Hi,

I bought an nrf51822 beacon from ebay, it has an LED and a button. I am trying to figure out what pins the LED and the button are connected to, without much success. For a start, I was hoping the code below would blink the led, but it doesn't. The beacon works fine, I can run other code on it, and the LED did work with the original firmware. Any other ideas?

for (int pin_number = 1; pin_number <= 31; pin_number++) {
	nrf_gpio_cfg_output(pin_number);    //config pin as output
}

while (true) {
	for (int pin_number = 1; pin_number <= 31; pin_number++) {
		nrf_gpio_pin_toggle(pin_number);
		nrf_delay_ms(500);
	}
}

Thanks!

[Johannes]

Hi Calin,

I am looking at a similar project (reprogramming those chinese iBeacons for a different purpose). Can you share anything you have learned? I will start tomorrow trying to program the flash through the nRF DK using the swdio but it seems daunting. The difference between the QFAA and the QFAC is just the beginning I guess.

Thanks in advance!

[Calin M]

Hi Johannes,

Here are the schematics:

https://drive.google.com/drive/folders/1nbTQ9UkFYFB1UESDMIMpEI_YteWTDJCu?usp=sharing

The company is very helpful and communicative (Radioland)

I used one of these for programming:

https://www.ebay.com/itm/J-Link-OB-ARM-Debugger-Programmer-Downloader-replace-v8-SWD-M74-New-/331807270184?hash=item4d41412528

had to solder wires, but I should probably make a flashing device to program bulk, something that clamps on the contact points.

I was using the gcc toolchain, I had to create a *.h file for this board, but I'm not sure I got all the values right. If I can find it, I'll post it (haven't had time for this for a while). Did not have any problems with the hardware. The lack of memory is a bit limiting because I did not have space for some of the software I wanted to flash on them. I wanted to create a mesh application, but some software did not compile small enough, some other did not run low power enough.

I haven't tried the original firmware and phone app, not sure what it does.

Good luck, let me know how it goes.

C.

[Johannes]

Oh awesome!. Did you ever try to program it using the nrf5x DK board? Supposedly that's possible. You don't have the .h file by any chance?

[Calin M]

the .h file will likely not match your sdk version, just take the "custom" board setup and modify it.

I don't use the nrf5 DK boards, but I imagine the programmer is connected to the onboard 51822 with some jumpers that you can disconnect and you can hook up this board instead.

[jaquoh]

Hey Johannes,

I was very happy to find this thread and someone who tinkered with these chinese iBeacons, too. (I have one with a nRF51822 and one with a nRF5282 chip, both QFAA)

I am in the very same situation you were, as I want to reprogram them and am on the hunt for information on best practices and tools to do this. Your post is 2 years old now, so I guess you have finished your project?

My current plan is to connect them with the OB-ARM Debugger and start with a ble_advertising sample from the nordic sdk for nRF51xx via Segger Embedded Studio.

So my question is exactly the same right now to get me started: Can you share anything you have learned?

kind regards

jaquoh

[Johannes]

Hi Jaquoh,

a project like that is never finished :-) but yes I got pretty far. The main issue for me was to find a beacon that met the mechanical requirements - I needed a push button that goes on a lanyard - and I finally settled for this particular one: https://www.alibaba.com/product-detail/CR2032-battery-broadcasting-sensor-ibeacon-with_60801253300.html

The first job is to find the programming pins - ususlly these chinese vendors are quite helpful. I ended up soldering jumper pins to the pads on the PCB so that it was easier to connect them to the Nordic DK - these are able to program and debug external devices. see https://devzone.nordicsemi.com/f/nordic-q-a/14058/external-programming-using-nrf52-dk

Once you have successfully connected the device you can start with one of the SDK examples and go from there.

Currently I have the vendor make batches of 100 for me, I just email them the firmware and they program it for me at the factory.

Johannes