Feature idea: Flipper as a pager

Sub-GHz
#1

I’ve noticed using my Flipper and the qFlipper Android app by bluetooth that clearly things can happen on it in the background that make it do things. Things like software updates and the ‘play alert on flipper’ feature. I think a good feature to add to the software would be a way of using it as a pager where a message can be broadcast and the flipper picks it up and beeps and viabrates.

A good way so that one could broadcast these messages with a decent amount of power would be for it to use citizens band radio channels. I am in Australia and I have a five watt UHF radio and I think the flipper can receive these channels. It could be good if the broadcast containing the data which sends a ‘page’ to a Flipper worked as audio, because then one could hold the transmit button on their CB radio while it is near a computer speaker which beeps and such into it - this would make it very easy.

I am no radio expert however and there might be serious issues that make my whole idea impossible. I still think the essential concept of using a Flipper as a pager could be a neat idea. In my own life this feature could tell me if there are security or even server problems at home while I am out getting lunch. On another note there are no networks in my country Australia for pagers anymore, but there is stuff out there so we can build one.

4 Likes
#2

I really like this idea; I see more than a few genuine use cases for this feature.

For instance:

  • Page all nearby Flippers, sending a silent(vibration) or audible alert. Wouldn’t it be cool to just send out a ‘chirp’ to all nearby flippers and discover and get to know people that have a flipper just like you. Then again, I would also like to be able to set my Flipper to ignore these messages/alerts.
  • Page friendly flippers that must be known to the sender.
  • These could be a bare notification, or pre-programmed text messages.
  • A more advanced feature would be sending text messages through the app with bluetooth to the flipper, which sends it to other (known) flippers over 315/433/868
  • Have Flipper work as a Notification Device for HomeAssistant. If your Home Assistant network has a 315/433/868 OOK/GFSK transceiver being able to send alerts and messages to Flipper from your HomeAssistant network would allow unlimited automation possibilities. So send a home automation alert through Sub-GHz to your Flipper, which triggers a silent or audible alert, and includes information like a sensor state, temperature, short text string etc.

I think a frequency and message frame standard would need to be standardized on, same as with a transmission method such as FSK/GFSK/OOK or even POCSAG.

It would be important to use the license-free “ISM” frequencies, such as 315/433/868. These frequencies are meant for these type of machine-to-machine transmissions, and are allowed worldwide. The Aussie UHF CB freqs aren’t available worldwide, and AFAIK are only allowed FM analog voice or DMR digital radio.

I think this would require to have this pager functionality to work in the background, while it isn’t being used or in “sleepmode” i.e when I have it in my pocket. I don’t know if this is possible.

5 Likes
#3

I’m literally working rn on a service that will allow you to do this :slight_smile:

17 Likes
#4

I am pleased to hear this is being worked on, when will it be in a beta or an RC release so I can give it a try?

#5

No estimates yet, this is a presonal project, so you’ll just have to wait

Probably after SD card plugins are released

1 Like
#6

Any updates? This sounds really cool

#7

It’s a personal project by one of the Flipper developers. It could be here tomorrow, or next year, or never.

You can already try flipper chat through the cli tools

2 Likes
#8

I’m currently working on POCSAG on flipper. At the moment, I have a subghz implementation of protocol, which can receive messages from my MMDVM setup. The code is here: GitHub - Shmuma/flipperzero-firmware at pocsag

It is not very optimal, as it does data decoding on MCU, but for fixed-rate 2FSK modulated data, CC1101 can do it itself. But my goal was to understand the POCSAG details.

The next step could be implementing packed mode receive using CC1101 and implement proper pager fap application.

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3 Likes
#9

Very coollll ! Thanks for sharing.

#10

If anybody wants to experiment with POCSAG reception, the first version of decoder is quite stable, have plans to create the PR after couple of tests and tweaks.

To receive POCSAG on flipper custom cc1101 preset has to be added, as default FM modulations in flipper are not compatible with POCSAG (it requires 9-15KHz bandwidth). To add the preset, you need to put text file in /ext/subghz/assets/setting_user with lines

# DAPNET frequency in most countries
Frequency: 439987500

# FM 15KHz preset
Custom_preset_name: FM150
Custom_preset_module: CC1101
Custom_preset_data: 02 0D 0B 06 08 32 07 04 14 00 13 02 12 04 11 83 10 67 15 31 18 18 19 16 1D 91 1C 00 1B 07 20 FB 22 10 21 56 00 00 C0 00 00 00 00 00 00 00

I have the sample file in my repo: flipperzero-firmware/setting_user.pocsag at pocsag · Shmuma/flipperzero-firmware · GitHub

Then, new frequency and modulation will appear in subghz configuration menus.

At the moment, my decoder supports only ascii messages, BCD and alert functions are not supported. Going to implement and test them in upcoming days. In addition, reception of several messages in one transmission hasn’t been tested yet (by default, MMDVM command tool sends only one message at a time).

3 Likes
#11

The progress is good to see, though I could not find any resources on making a POCSAG broadcast with an SDR. I might have just not looked hard enough, but it would be best if I could broadcast these messages with my HackRF one. With that capability I could contribute to testing.

In my country there has been no pager providers or services for a long time, and it might actually be best to just a protocol for Flipper/SDR users to have a pager system that is open and uses frequencies that do not require a licence, such as citizens band.

#12

Had the same problem some time ago, solved it with MMDVM raspberry pi hat. With pi-star installed you can transmit pocsag messages from command line.

At the moment, that’s my primary way of testing flipper pocsag decoder

1 Like
#13

Awesome! I will be testing this out myself with a known, pocsag ascii paging system used for our Fire and EMS services. Also in the 450 band.

1 Like
#14

That would be great! Let me know about the results. Are you in Germany?

Current version might be not very practical, as it requires explicit receive initiate, but in the future I’d like to make proper pager in Flipper. As far as I know, in Germany pagers are still very activery used not only by hobbysts, but also by emergency services. Given quite high price for pagers (good ones are comparable to Flipper Zero), it might be really nice use-case.

1 Like
#15

Very cool! I have a couple MMDVM. I will be following this thread and waiting for my Flipper!

#16

Hi. I tried to use it with my flipper, but not sure how I can decode pocsag. I’m on RM firmware, do I need app for this ? Thanks.