- [1.1. Q: What is MeshCore?](#11-q-what-is-meshcore)
- [1.2. Q: What do you need to start using MeshCore?](#12-q-what-do-you-need-to-start-using-meshcore)
- [1.2.1. Hardware](#121-hardware)
- [1.2.2. Firmware](#122-firmware)
- [1.2.3. Companion Radio Firmware](#123-companion-radio-firmware)
- [1.2.4. Repeater](#124-repeater)
- [1.2.5. Room Server](#125-room-server)
- [2. Initial Setup](#2-initial-setup)
- [2.1. Q: How many devices do I need to start using MeshCore?](#21-q-how-many-devices-do-i-need-to-start-using-meshcore)
- [2.2. Q: Does MeshCore cost any money?](#22-q-does-meshcore-cost-any-money)
- [2.3. Q: What frequencies are supported by MeshCore?](#23-q-what-frequencies-are-supported-by-meshcore)
- [2.4. Q: What is an "advert" in MeshCore?](#24-q-what-is-an-advert-in-meshcore)
- [2.5. Q: Is there a hop limit?](#25-q-is-there-a-hop-limit)
- [3. Server Administration](#3-server-administration)
- [3.1. Q: How do you configure a repeater or a room server?](#31-q-how-do-you-configure-a-repeater-or-a-room-server)
- [3.2. Q: Do I need to set the location for a repeater?](#32-q-do-i-need-to-set-the-location-for-a-repeater)
- [3.3. Q: What is the password to administer a repeater or a room server?](#33-q-what-is-the-password-to-administer-a-repeater-or-a-room-server)
- [3.4. Q: What is the password to join a room server?](#34-q-what-is-the-password-to-join-a-room-server)
- [3.5. Q: Can I retrieve a repeater's private key or set a repeater's private key?](#35-q-can-i-retrieve-a-repeaters-private-key-or-set-a-repeaters-private-key)
- [3.6. Q: The first byte of my repeater's public key collides with an exisitng repeater on the mesh. How do I get a new private key with a matching public key that has its first byte of my choosing?](#36-q-the-first-byte-of-my-repeaters-public-key-collides-with-an-exisitng-repeater-on-the-mesh--how-do-i-get-a-new-private-key-with-a-matching-public-key-that-has-its-first-byte-of-my-choosing)
- [3.7. Q: My repeater maybe suffering from deafness due to high power interference near my mesh's frequency, it is not hearing other in-range MeshCore radios. What can I do?](#37-q-my-repeater-maybe-suffering-from-deafness-due-to-high-power-interference-near-my-meshs-frequency-it-is-not-hearing-other-in-range-meshcore-radios--what-can-i-do)
- [3.8. Q: How do I make my repeater an observer on the mesh?](#38-q-how-do-i-make-my-repeater-an-observer-on-the-mesh)
- [3.9. Q: What is multi-byte support? What do 1-byte, 2-byte, 3-byte adverts and messages mean?](#39-q-what-is-multi-byte-support--what-do-1-byte-2-byte-3-byte-adverts-and-messages-mean)
- [3.9.1. Q: **What path hash sizes will my repeater forward?**](#391-q-what-path-hash-sizes-will-my-repeater-forward)
- [3.9.2. Q: **What determines a packet's path hash size?**](#392-q-what-determines-a-packets-path-hash-size)
- [3.9.3. Q: **How do I change my companion's path hash size?**](#393-q-how-do-i-change-my-companions-path-hash-size)
- [3.9.4. Q: **What does `path.hash.mode` on a repeater do?**](#394-q-what-does-pathhashmode-on-a-repeater-do)
- [4. T-Deck Related](#4-t-deck-related)
- [4.1. Q: Is there a user guide for T-Deck, T-Pager, T-Watch, or T-Display Pro?](#41-q-is-there-a-user-guide-for-t-deck-t-pager-t-watch-or-t-display-pro)
- [4.2. Q: What are the steps to get a T-Deck into DFU (Device Firmware Update) mode?](#42-q-what-are-the-steps-to-get-a-t-deck-into-dfu-device-firmware-update-mode)
- [4.3. Q: Why is my T-Deck Plus not getting any satellite lock?](#43-q-why-is-my-t-deck-plus-not-getting-any-satellite-lock)
- [4.4. Q: Why is my OG (non-Plus) T-Deck not getting any satellite lock?](#44-q-why-is-my-og-non-plus-t-deck-not-getting-any-satellite-lock)
- [4.5. Q: What size of SD card does the T-Deck support?](#45-q-what-size-of-sd-card-does-the-t-deck-support)
- [4.6. Q: what is the public key for the default public channel?](#46-q-what-is-the-public-key-for-the-default-public-channel)
- [4.7. Q: How do I get maps on T-Deck?](#47-q-how-do-i-get-maps-on-t-deck)
- [4.8. Q: Where do the map tiles go?](#48-q-where-do-the-map-tiles-go)
- [4.9. Q: How to unlock deeper map zoom and server management features on T-Deck?](#49-q-how-to-unlock-deeper-map-zoom-and-server-management-features-on-t-deck)
- [4.10. Q: How to decipher the diagnostics screen on T-Deck?](#410-q-how-to-decipher-the-diagnostics-screen-on-t-deck)
- [4.11. Q: The T-Deck sound is too loud?](#411-q-the-t-deck-sound-is-too-loud)
- [4.12. Q: Can you customize the sound?](#412-q-can-you-customize-the-sound)
- [4.13. Q: What is the 'Import from Clipboard' feature on the t-deck and is there a way to manually add nodes without having to receive adverts?](#413-q-what-is-the-import-from-clipboard-feature-on-the-t-deck-and-is-there-a-way-to-manually-add-nodes-without-having-to-receive-adverts)
- [4.14. Q: How to capture a screenshot on T-Deck?](#414-q-how-to-capture-a-screenshot-on-t-deck)
- [5. General](#5-general)
- [5.1. Q: What are BW, SF, and CR?](#51-q-what-are-bw-sf-and-cr)
- [5.2. Q: Do MeshCore clients repeat?](#52-q-do-meshcore-clients-repeat)
- [5.3. Q: What happens when a node learns a route via a mobile repeater, and that repeater is gone?](#53-q-what-happens-when-a-node-learns-a-route-via-a-mobile-repeater-and-that-repeater-is-gone)
- [5.4. Q: How does a node discovery a path to its destination and then use it to send messages in the future, instead of flooding every message it sends like Meshtastic?](#54-q-how-does-a-node-discovery-a-path-to-its-destination-and-then-use-it-to-send-messages-in-the-future-instead-of-flooding-every-message-it-sends-like-meshtastic)
- [5.5. Q: Do public channels always flood? Do private channels always flood?](#55-q-do-public-channels-always-flood-do-private-channels-always-flood)
- [5.6. Q: what is the public key for the default public channel?](#56-q-what-is-the-public-key-for-the-default-public-channel)
- [5.7. Q: Is MeshCore open source?](#57-q-is-meshcore-open-source)
- [5.8. Q: How can I support MeshCore?](#58-q-how-can-i-support-meshcore)
- [5.9. Q: How do I build MeshCore firmware from source?](#59-q-how-do-i-build-meshcore-firmware-from-source)
- [5.10. Q: Are there other MeshCore related open source projects?](#510-q-are-there-other-meshcore-related-open-source-projects)
- [5.11. Q: Does MeshCore support ATAK](#511-q-does-meshcore-support-atak)
- [5.12. Q: How do I add a node to the MeshCore Map](#512-q-how-do-i-add-a-node-to-the-meshcore-map)
- [5.13. Q: Can I use a Raspberry Pi to update a MeshCore radio?](#513-q-can-i-use-a-raspberry-pi-to-update-a-meshcore-radio)
- [5.14. Q: Are there are projects built around MeshCore?](#514-q-are-there-are-projects-built-around-meshcore)
- [5.15. Q: Are there client applications for Windows or Mac?](#515-q-are-there-client-applications-for-windows-or-mac)
- [5.16. Q: Are there any resources that compare MeshCore to other LoRa systems?](#516-q-are-there-any-resources-that-compare-meshcore-to-other-lora-systems)
- [6. Troubleshooting](#6-troubleshooting)
- [6.1. Q: My client says another client or a repeater or a room server was last seen many, many days ago.](#61-q-my-client-says-another-client-or-a-repeater-or-a-room-server-was-last-seen-many-many-days-ago)
- [6.2. Q: A repeater or a client or a room server I expect to see on my discover list (on T-Deck) or contact list (on a smart device client) are not listed.](#62-q-a-repeater-or-a-client-or-a-room-server-i-expect-to-see-on-my-discover-list-on-t-deck-or-contact-list-on-a-smart-device-client-are-not-listed)
- [6.3. Q: How to connect to a repeater via BLE (Bluetooth)?](#63-q-how-to-connect-to-a-repeater-via-ble-bluetooth)
- [6.4. Q: My companion isn't showing up over Bluetooth?](#64-q-my-companion-isnt-showing-up-over-bluetooth)
- [6.5. Q: I can't connect via Bluetooth, what is the Bluetooth pairing code?](#65-q-i-cant-connect-via-bluetooth-what-is-the-bluetooth-pairing-code)
- [6.6. Q: My Heltec V3 keeps disconnecting from my smartphone. It can't hold a solid Bluetooth connection.](#66-q-my-heltec-v3-keeps-disconnecting-from-my-smartphone--it-cant-hold-a-solid-bluetooth-connection)
- [6.7. Q: My RAK/T1000-E/xiao\_nRF52 device seems to be corrupted, how do I wipe it clean to start fresh?](#67-q-my-rakt1000-exiao_nrf52-device-seems-to-be-corrupted-how-do-i-wipe-it-clean-to-start-fresh)
- [6.8. Q: WebFlasher fails on Linux with failed to open](#68-q-webflasher-fails-on-linux-with-failed-to-open)
- [7. Other Questions:](#7-other-questions)
- [7.1. Q: How to update nRF (RAK, T114, Seed XIAO) repeater and room server firmware over the air using the new simpler DFU app?](#71-q-how-to-update-nrf-rak-t114-seed-xiao-repeater-and-room-server-firmware-over-the-air-using-the-new-simpler-dfu-app)
- [7.1.1 Q: Can I update Seeed Studio Wio Tracker L1 Pro using OTA?](#711-q-can-i-update-seeed-studio-wio-tracker-l1-pro-using-ota)
- [7.2. Q: How to update ESP32-based devices over the air?](#72-q-how-to-update-esp32-based-devices-over-the-air)
- [7.3. Q: Is there a way to lower the chance of a failed OTA device firmware update (DFU)?](#73-q-is-there-a-way-to-lower-the-chance-of-a-failed-ota-device-firmware-update-dfu)
- [7.4. Q: are the MeshCore logo and font available?](#74-q-are-the-meshcore-logo-and-font-available)
- [7.5. Q: What is the format of a contact or channel QR code?](#75-q-what-is-the-format-of-a-contact-or-channel-qr-code)
- [7.6. Q: How do I connect to the companion via WIFI, e.g. using a heltec v3?](#76-q-how-do-i-connect-to-the-companion-via-wifi-eg-using-a-heltec-v3)
- [7.7. Q: I have a Station G2, or a Heltec V4, or an Ikoka Stick, or a radio with a EByte E22-900M30S or a E22-900M33S module, what should their transmit power be set to?](#77-q-i-have-a-station-g2-or-a-heltec-v4-or-an-ikoka-stick-or-a-radio-with-a-ebyte-e22-900m30s-or-a-e22-900m33s-module-what-should-their-transmit-power-be-set-to)
- [⚠️ **WARNING: Set these values at your own risk. Incorrect power settings can permanently damage your radio hardware.**](#️-warning-set-these-values-at-your-own-risk-incorrect-power-settings-can-permanently-damage-your-radio-hardware)
**A:** MeshCore is a multi platform system for enabling secure text based communications utilising LoRa radio hardware. It can be used for Off-Grid Communication, Emergency Response & Disaster Recovery, Outdoor Activities, Tactical Security including law enforcement and private security and also IoT sensor networks. ([source](https://meshcore.co.uk/))
Some more advanced, but optional features are available on T-Deck if you register your device for a key to unlock. On the MeshCore smartphone clients for Android and iOS/iPadOS, you can unlock the wait timer for repeater and room server remote management over RF feature.
These features are completely optional and aren't needed for the core messaging experience. They're like super bonus features and to help the developers continue to work on these amazing features, they may charge a small fee for an unlock code to utilise the advanced features.
Anyone is able to build anything they like on top of MeshCore without paying anything.
MeshCore is available on a variety of 433MHz, 868MHz and 915MHz LoRa devices. For example, Lilygo T-Deck, T-Pager, RAK Wireless WisBlock RAK4631 devices (e.g. 19003, 19007, 19026), Heltec V3, Xiao S3 WIO, Xiao C3, Heltec T114, Station G2, Nano G2 Ultra, Seeed Studio T1000-E. More devices are being added regularly.
To use MeshCore without using a phone as the client interface, you can run MeshCore on a LiLygo's T-Deck, T-Deck Plus, T-Pager, T-Watch, or T-Display Pro. MeshCore Ultra firmware running on these devices are a complete off-grid secure communication solution.
USB Serial Companion firmware runs on a supported LoRa device and connects to a smart device or a computer over USB Serial running the MeshCore web client
Repeaters are used to extend the range of a MeshCore network. Repeater firmware runs on the same devices that run client firmware. A repeater's job is to forward MeshCore packets to the destination device. It does **not** forward or retransmit every packet it receives, unlike other LoRa mesh systems.
A repeater can be remotely administered using a T-Deck running the MeshCore firmware with remote administration features unlocked, or from a BLE Companion client connected to a smartphone running the MeshCore app.
A room server is a simple BBS server for sharing posts. T-Deck devices running MeshCore firmware or a BLE Companion client connected to a smartphone running the MeshCore app can connect to a room server.
Room servers store message history on them and push the stored messages to users. Room servers allow roaming users to come back later and retrieve message history. With channels, messages are either received when it's sent, or not received and missed if the channel user is out of range. Room servers are different and more like email servers where you can come back later and get your emails from your mail server.
A room server can be remotely administered using a T-Deck running the MeshCore firmware with remote administration features unlocked, or from a BLE Companion client connected to a smartphone running the MeshCore app.
Although room server can also repeat with the command line command `set repeat on`, it is not recommended nor encouraged. A room server with repeat set to `on` lacks the full set of repeater and remote administration features that are only available in the repeater firmware.
**A:** If you have one supported device, flash the BLE Companion firmware and use your device as a client. You can connect to the device using the Android or iOS client via Bluetooth. You can start communicating with other MeshCore users near you.
If you have two supported devices, and there are not many MeshCore users near you, flash both to BLE Companion firmware so you can use your devices to communicate with your near-by friends and family.
If you have two supported devices, and there are other MeshCore users nearby, you can flash one of your devices with BLE Companion firmware and flash another supported device to repeater firmware. Place the repeater high above ground to extend your MeshCore network's reach.
After you flashed the latest firmware onto your repeater device, keep the device connected to your computer via USB serial, use the console feature on the web flasher and set the frequency for your region or country, so your client can remote administer the repeater or room server over RF:
The native Android and iOS client uses the freemium model and is developed by Liam Cottle, developer of meshtastic map at [meshtastic.liamcottle.net](https://meshtastic.liamcottle.net) on [GitHub](https://github.com/liamcottle/meshtastic-map) and [reticulum-meshchat on github](https://github.com/liamcottle/reticulum-meshchat).
The T-Deck firmware is free to download and most features are available without cost. To support the firmware developer, you can pay for a registration key to unlock your T-Deck for deeper map zoom and remote server administration over RF using the T-Deck. You do not need to pay for the registration to use your T-Deck for direct messaging and connecting to repeaters and room servers.
**A:** It supports the 868MHz range in the UK/EU and the 915MHz range in New Zealand, Australia, and the USA. Countries and regions in these two frequency ranges are also supported.
Recently, as of October 2025, many regions have moved to the "narrow" setting, aka using BW62.5 and a lower SF number (instead of the original SF11). For example, USA/Canada (Recommended) preset is 910.525MHz, SF7, BW62.5, CR5.
After extensive testing, many regions have switched or about to switch over to BW62.5 and SF7, 8, or 9. Narrower bandwidth setting and lower SF setting allow MeshCore's radio signals to fit between interference in the ISM band, provide for a lower noise floor, better SNR, and faster transmissions.
If you have consensus from your community in your region to update your region's preset recommendation, please post your update request on the [#meshcore-app](https://discord.com/channels/1343693475589263471/1391681655911088241) channel on the [MeshCore Discord server ](https://discord.gg/cYtQNYCCRK) to let Liam Cottle know.
Advert means to advertise yourself on the network. In Reticulum terms it would be to announce. In Meshtastic terms it would be the node sending its node info.
MeshCore allows you to manually broadcast your name, position and public encryption key, which is also signed to prevent spoofing. When you click the advert button, it broadcasts that data over LoRa. MeshCore calls that an Advert. There's two ways to advert, "zero hop" and "flood".
* Zero hop means your advert is broadcasted out to anyone that can hear it, and that's it.
MeshCore clients only advertise themselves when the user initiates it. A repeater sends a flood advert once every 12 hours by default. This interval can be configured using the following command:
**A:** Internally the firmware has maximum limit of 64 hops. In real world settings it will be difficult to get close to the limit due to the environments and timing as packets travel further and further. We want to hear how far your MeshCore conversations go.
**A:** - When MeshCore is flashed onto a LoRa device is for the first time, it is necessary to set the server device's frequency to make it utilize the frequency that is legal in your country or region.
- After a repeater or room server firmware is flashed on to a LoRa device, go to <https://config.meshcore.dev> and use the web user interface to connect to the LoRa device via USB serial. From there you can set the name of the server, its frequency and other related settings, location, passwords etc.
- Connect the server device using a USB cable to a computer running Chrome on https://flasher.meshcore.co.uk/, then use the `console` feature to connect to the device
- Use a MeshCore smartphone clients to remotely administer servers via LoRa.
- A T-Deck running unlocked/registered MeshCore firmware. Remote server administration is enabled through registering your T-Deck with Ripple Radios. It is one of the ways to support MeshCore development. You can register your T-Deck at:
**A:** While not required, with location set for a repeater it will show up on the MeshCore map in the future. Set location with the following command:
Reboot the repeater after `set prv.key <hex>` command for the new private key to take effect.
### 3.6. Q: The first byte of my repeater's public key collides with an exisitng repeater on the mesh. How do I get a new private key with a matching public key that has its first byte of my choosing?
**A:** You can generate a new private key and specific the first byte of its public key here: https://gessaman.com/mc-keygen/
Having multiple repeaters with the same first byte ID does not negatively affect the mesh or its functionality. Flood and pathed packets will still reach their destinations. First byte ID collision makes traceroute and path analysis harder because these tools don't know exactly which of the two (or more) colliding repeaters is the one in the path.
Best practice is when you set up a new repeater, choose a public key that is not in use. If it is not possible to find a unique first byte for your repeater's public key, choose one that is unique within about 10 miles (16 km) to minimize collision with nearby repeaters.
### 3.7. Q: My repeater maybe suffering from deafness due to high power interference near my mesh's frequency, it is not hearing other in-range MeshCore radios. What can I do?
The `<number>` unit is in seconds and is incremented by 4. `set agc.reset.interval 4` works well to cure deafness.
This is a very low cost operation. AGC reset is done by simply setting `state = STATE_IDLE;` in function `RadioLibWrapper::resetAGC()` in `RadioLibWrappers.cpp`
### 3.9. Q: What is multi-byte support? What do 1-byte, 2-byte, 3-byte adverts and messages mean?
**A:**
**Background:**
The orginal MeshCore protocol design uses the first byte of a repeater's public key to denote the repeater in a path. And with 1 byte for each repeater in the path, MeshCore packets can travel as many as 64 hops.
However, with 1 byte, there are only 254 unique IDs (exclude 00 and FF which are reserved). Many meshes group have multiple repeaters with the same first byte in their public keys. Packets continue to pass through repeaters and the mesh is not harmed in anyway. It does make it harder for tools to analyze paths with duplicated repeater IDs.
Firmware version 1.14 and newer introduces the ability for repeaters to advert with 1-, 2-, or 3-byte adverts. Companions can also send out channel and direct messages 1-, 2-, or 3-byte path. Adverts and messages sent in 1-byte path is compatible with repeater firmware older or newer than 1.14. They will travel up to 64 hops. 2-byte adverts and messages will travel up to 32 hops. 3-byte adverts and messages will travel up to 21 hops.
### 3.9.1. Q: **What path hash sizes will my repeater forward?**
Repeaters running firmware 1.14+ will repeat packets with 1-, 2-, or 3-byte path hash. Repeaters on firmware older than 1.14 will only repeat 1-byte path hash packets and will silently drop 2- and 3-byte packets.
### 3.9.2. Q: **What determines a packet's path hash size?**
The original sender. The most common original sender is a companion app. The other common original sender is a repeater, when it broadcasts its advert.
### 3.9.3. Q: **How do I change my companion's path hash size?**
As of firmware 1.14, you can set your companion's message path hash size in the Experimental settings section of the app. Until your regional mesh has the vast majority of the repeaters updated to 1.14+ firmware, it is recommended to keep your companion at the default 1-byte because pre-1.14 repeaters will silently drop messages with larger path hashes.
### 3.9.4. Q: **What does `path.hash.mode` on a repeater do?**
It *only* controls the path hash size used in that repeater's own advert broadcasts. It does **not** affect which packets the repeater forwards. A 1.14+ repeater will always forward 1-, 2-, and 3-byte packets regardless of this setting.
You can set it with `set path.hash.mode {0|1|2}`:
```
┌────────────────┬───────────────────────┐
│ path.hash.mode │ Advert path hash size │
├────────────────┼───────────────────────┤
│ 0 │ 1 byte (default) │
├────────────────┼───────────────────────┤
│ 1 │ 2 bytes │
├────────────────┼───────────────────────┤
│ 2 │ 3 bytes │
└────────────────┴───────────────────────┘
```
It is safe to set your 1.14+ repeaters to mode 1 or 2.
**Why use 2- or 3-byte path hash for adverts?**
A longer path hash helps tools like the LetsMesh Analyzer and MeshMapper disambiguate repeaters more reliably. With only 1 byte, the chance of different repeaters have the same first byte in their public key is high, making it harder to tell them apart in network analysis. Since this only affects adverts, there's no downside. 2- and 3-byte adverts don't travel as far, but it is not important for MechCore nodes to hear a repeater's advert that is 21 or 32 hops away.
**When can we move away from 1-byte path hash?**
You should move to send 2-byte or 3-byte channel and direct messages when the vast majority of the repeaters in your regional mesh are updated to firmware version 1.14 or newer. Setting your repeater's `path.hash.mode` to 1 (for 2-byte path) or 2 (for 3-byte path) helps the community gauge how many repeaters have updated to 1.14+. Please work with your MeshCore community together to decide when to switch to 2-byte path or 3-byte path for messages.
**A:** For T-Deck Plus, the GPS baud rate should be set to **38400**. Also, some T-Deck Plus devices were found to have the GPS module installed upside down, with the GPS antenna facing down instead of up. If your T-Deck Plus still doesn't get any satellite lock after setting the baud rate to 38400, you might need to open the device to check the GPS orientation.
GPS on T-Deck is always enabled. You can skip the "GPS clock sync" and the T-Deck will continue to try to get a GPS lock. You can go to the `GPS Info` screen; you should see the `Sentences:` counter increasing if the baud rate is correct.
**A:** The OG (non-Plus) T-Deck doesn't come with a GPS. If you added a GPS to your OG T-Deck, please refer to the manual of your GPS to see what baud rate it requires. Alternatively, you can try to set the baud rate from 9600, 19200, etc., and up to 115200 to see which one works.
There is no `=` key on the T-Deck's hardware keyboard. You can use the on-screen software keyboard to enter `=`. Tap the text box to enable the on-screen software keyboard.
**A:** You can download, install, and use the T-Deck firmware for free, but it has some features (map zoom, server administration) that are enabled if you purchase an unlock code for \$10 per T-Deck device.
**A:** 'Import from Clipboard' is for importing a contact via a file named 'clipboard.txt' on the SD card. The opposite, is in the Identity screen, the 'Card to Clipboard' menu, which writes to 'clipboard.txt' so you can share yourself (call these 'biz cards', that start with "meshcore://...")
### 4.14. Q: How to capture a screenshot on T-Deck?
**A:** To capture a screenshot on a T-Deck, long press the top-left corner of the screen. The screenshot is saved to the microSD card, if one is inserted into the device.
Forward Error Correction is a process of adding redundant bits to the data to be transmitted. During the transmission, data may get corrupted by interference (changes from 0 to 1 / 1 to 0). These error correction bits are used at the receivers for restoring corrupted bits.
The Code Rate of a forward error correction expresses the proportion of bits in a data stream that actually carry useful information.
There are 4 code rates used in LoRaWAN:
4/5
4/6
5/7
4/8
For example, if the code rate is 5/7, for every 5 bits of useful information, the coder generates a total of 7 bits of data, of which 2 bits are redundant.
Making the bandwidth 2x wider (from BW125 to BW250) allows you to send 2x more bytes in the same time. Making the spreading factor 1 step lower (from SF10 to SF9) allows you to send 2x more bytes in the same time.
Lowering the spreading factor makes it more difficult for the gateway to receive a transmission, as it will be more sensitive to noise. You could compare this to two people taking in a noisy place (a bar for example). If you’re far from each other, you have to talk slow (SF10), but if you’re close, you can talk faster (SF7)
**A:** No, MeshCore clients do not repeat. This is the core of MeshCore's messaging-first design. This is to avoid devices flooding the air ware and create endless collisions, so messages sent aren't received.
In MeshCore, only repeaters and room server with `set repeat on` repeat.
**A:** If you used to reach a node through a repeater and the repeater is no longer reachable, the client will send the message using the existing (but now broken) known path, the message will fail after 3 retries, and the app will reset the path and send the message as flood on the last retry by default. This can be turned off in settings. If the destination is reachable directly or through another repeater, the new path will be used going forward. Or you can set the path manually if you know a specific repeater to use to reach that destination.
In the case if users are moving around frequently, and the paths are breaking, they just see the phone client retries and revert to flood to attempt to re-establish a path.
### 5.4. Q: How does a node discovery a path to its destination and then use it to send messages in the future, instead of flooding every message it sends like Meshtastic?
Routes are stored in sender's contact list. When you send a message the first time, the message first gets to your destination by flood routing. When your destination node gets the message, it will send back a delivery report to the sender with all repeaters that the original message went through. This delivery report is flood-routed back to you the sender and is a basis for future direct path. When you send the next message, the path will get embedded into the packet and be evaluated by repeaters. If the hop and address of the repeater matches, it will retransmit the message, otherwise it will not retransmit, hence minimizing utilization.
**A:** Yes, group channels are A to B, so there is no defined path. They have to flood. Repeaters can however deny flood traffic up to some hop limit, with the `set flood.max` CLI command. Administrators of repeaters get to set the rules of their repeaters.
**A:** Provide your honest feedback on GitHub and on [MeshCore Discord server](https://discord.gg/BMwCtwHj5V). Spread the word of MeshCore to your friends and communities; help them get started with MeshCore. Support Scott's MeshCore development at <https://buymeacoffee.com/ripplebiz>.
Support Liam Cottle's smartphone client development by unlocking the server administration wait gate with in-app purchase
Support Rastislav Vysoky (recrof)'s flasher web site and the map web site development through [PayPal](https://www.paypal.com/donate/?business=DREHF5HM265ES&no_recurring=0&item_name=If+you+enjoy+my+work%2C+you+can+support+me+here%3A¤cy_code=EUR) or [Revolut](https://revolut.me/recrof)
MeshCore clients would need to reset path constantly and flood traffic across the network which could lead to lots of collisions with something as chatty as ATAK.
To add a BLE Companion radio, connect to the BLE Companion radio from the MeshCore smartphone app. In the app, tap the `3 dot` menu icon at the top right corner, then tap `Internet Map`. Tap the `3 dot` menu icon again and choose `Add me to the Map`
To add a Repeater or Room Server to the map, go to the Contact List, tap the `3 dot` next to the Repeater or Room Server you want to add to the Internet Map, tap `Share`, then tap `Upload to Internet Map`.
You can use the same companion (same public key) that you used to add your repeaters or room servers to remove them from the Internet Map.
- Merged bin overwrites everything including the bootloader, existing Bluetooth pairing database, but keeps configurations.
- Right click on the file name and copy the link and note it for later use here is an example: `https://flasher.meshcore.dev/releases/download/companion-v1.7.1/Heltec_v3_companion_radio_ble-v1.7.1-165fb33.bin`
- Run:
-`wget https://flasher.meshcore.dev/releases/download/companion-v1.7.1/Heltec_v3_companion_radio_ble-v1.7.1-165fb33.bin` to download the firmware file for your device type. or the version you need - USB, BLE, Repeater, Room Server, merged bin or non-merged bin
- If the above wget command only downloads a very small file (10K bytes instead of more than 100K byte, use this command instead:
- Right click on the file name and copy the link and note it for later use here is an example: `https://flasher.meshcore.dev/releases/download/companion-v1.7.1/RAK_4631_companion_radio_ble-v1.7.1-165fb33.zip`
- Run:
-`wget https://flasher.meshcore.dev/releases/download/companion-v1.7.1/RAK_4631_companion_radio_ble-v1.7.1-165fb33.zip` to download the firmware file for your device type. or the version you need - USB, BLE, Repeater, Room Server, ZIP file only
- Confirm the `ttyXXXX` device path on your Raspberry Pi:
- Go to `/dev` directory, run ls command to find confirm your device path
To manage a repeater or room server connected to a Pi over USB serial using shell commands, you need to install `picocom`. To install `picocom`, run the following command:
-`sudo apt install picocom`
To start managing your USB serial-connected device using picocom, use the following command:
**A:** Yes, there are many. MeshCore's protocol is open source using the MIT license. The MIT license and the open source protocol makes it very easy for the MeshCore community to build new firmware for radios, applications on mobile devices, map tools, and analysis tools, and integration with other projects like Home Asistant.
As new MeshCore community projects become available on a weekly basis, we have stopped tracking them here in this FAQ. [samuk](https://github.com/samuk) maintains a very exhausive list of MeshCore community project at https://github.com/samuk/awesome-meshcore/blob/main/README.md. samuk accepts PRs and merges them regularly.
**A:** Yes, the same iOS and Android client is also available for Windows and Intel Mac (sorry, not available for ARM-based Mac yet). You can find them together with the Android APK here:
https://files.liamcottle.net/MeshCore
Both the Windows and Intel Mac versions of the client app are fully unlocked and are free to use.
### 6.1. Q: My client says another client or a repeater or a room server was last seen many, many days ago.
### 6.2. Q: A repeater or a client or a room server I expect to see on my discover list (on T-Deck) or contact list (on a smart device client) are not listed.
You can get the epoch time on <https://www.epochconverter.com/> and use it to set your T-Deck clock. For a repeater and room server, the admin can use a T-Deck to remotely set their clock (clock sync), or use the `time` command in the USB serial console with the server device connected.
### 6.3. Q: How to connect to a repeater via BLE (Bluetooth)?
**A:** You can't connect to a device running repeater firmware via Bluetooth. Devices running the BLE companion firmware you can connect to it via Bluetooth using the android app
**A:** Heltec V3 has a very small coil antenna on its PCB for Wi-Fi and Bluetooth connectivity. It has a very short range, only a few feet. It is possible to remove the coil antenna and replace it with a 31mm wire. The BT range is much improved with the modification.
- For Xiao nRF52, click the reset button once. If that doesn't work, quickly double click the reset button twice. If that doesn't work, disconnection the board from your PC and reconnect again ([seeed studio wiki](https://wiki.seeedstudio.com/XIAO_BLE/#access-the-swd-pins-for-debugging-and-reflashing-bootloader))
5. A new folder will appear on your computer's desktop
Separately, starting in firmware version 1.7.0, there is a CLI Rescue mode. If your device has a user button (e.g. some RAK, T114), you can activate the rescue mode by hold down the user button of the device within 8 seconds of boot. Then you can use the 'Console' on flasher.meshcore.co.uk
1. Download nRF's DFU app from iOS App Store or Android's Play Store, you can find the app by searching for `nrf dfu`, the app's full name is `nRF Device Firmware Update`
2. On flasher.meshcore.co.uk, download the **ZIP** version of the firmware for your nRF device (e.g. RAK or Heltec T114 or Seeed Studio's Xiao)
After this bootloader is flashed onto the device, you can trigger over the air update using bluetooth by holding the button next to the D-Pad and then click the reset button. The follow the same OTA update instructions above. You can skip pass the `start ota` instruction and start the update using the DFU app.
1. On flasher.meshcore.co.uk, download the **non-merged** version of the firmware for your ESP32 device (e.g. `Heltec_v3_repeater-v1.6.2-4449fd3.bin`, no `"merged"` in the file name)
**A:** Yes, developer `che aporeps` has an enhanced OTA DFU bootloader for nRF52 based devices. With this bootloader, if it detects that the application firmware is invalid, it falls back to OTA DFU mode so you can attempt to flash again to recover. This bootloader has other changes to make the OTA DFU process more fault tolerant.
### 7.7. Q: I have a Station G2, or a Heltec V4, or an Ikoka Stick, or a radio with a EByte E22-900M30S or a E22-900M33S module, what should their transmit power be set to?
**A:**
For companion radios, you can set these radios' transmit power in the smartphone app. For repeater and room server radios, you can set their transmit power using the command line command `set tx`. You can get their current value using command line comand `get tx`
| | US915 Max at 1dB compression point | 16 dBm | 35 dBm (3.16W) | 1dB compression point |
| | EU868 Max at 1dB compression point | 15 dBm | 34.5 dBm (2.82W) | 1dB compression point |
| | US915 1W Output | 10 dBm | 1W | Refer to your local government's requirements |
| | EU868 1W Output | 9 dBm | 1W |Refer to your local government's requirements |
| **Ikoka Stick E22-900M30S** | 1W Model | 19 dBm | 1W | **DO NOT EXCEED** (Risk of burn out) [data sheet](https://www.cdebyte.com/pdf-down.aspx?id=4216) |
| **Ikoka Stick E22-900M33S** | 2W Model | 9 dBm | 2W | **DO NOT EXCEED** (Risk of burn out) [data sheet](https://www.cdebyte.com/pdf-down.aspx?id=4216) Refer to your local government's requirements |
