To build a multimode digital repeater, G4KLX have developped a complete software called MMDVM (Multimode Digital Voice Modem). It is compatible of main digital modes (to date, C4FM, DSTAR and DMR).
This board interfac on one side transmitter and receiver and, on the second hand the Arduino Due. A computer (such as a Raspberry Pi for example) is connect via USB to the Arduino. This provide a complete controler for numerical repeater.
I design this PCB, like some other OM, with components in conventional sizes (DIL integrated circuit, resistors quarter-Watt, …). There is still a quite small component that is the TCXO . To eliminate an CMS component, I chose to install a HCMOS TCXO directly compatible of 3.3V expected voltage of the Arduino. The selected reference is the FOX924B-12 with an announced stability of +/- 2.5 ppm.
I replaced the bulky components (in TO220 housings) with equivalent components in TO92 case. The tests are to be carried out. However, even the largest components can be positioned, as I left the possibility of mounting one or the other versions. The board plugs directly on Arduino Due.
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- MMDVM board top view with TO220 components
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- MMDVM board top view with its components TO92
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- MMDVM board side view, connectors DIN 6 pins
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- MMDVM board side view,with direct connector for receiver and transmiter
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- MMDVM board without components
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- MMDVM below the board
The MMDVM hardware is under KI6ZUM CC licence BY/SA/NC
In PDF format : MMDVM F5UII v1.1
Here is the BOM
| Pos | Component | Value | Précision | Case |
| 1 | C1 | 10µF | D4R2,54_ELKO | |
| 2 | C2 | 10µF | D4R2,54_ELKO | |
| 3 | C3 | 10nF | 10% | 3X5R2,54 |
| 4 | C4 | 47µF | D4R2,54_ELKO | |
| 5 | C5 | 47µF | D4R2,54_ELKO | |
| 6 | C6 | 10nF | 10% | 3X5R2,54 |
| 7 | C7 | 10nF | 10% | 3X5R2,54 |
| 8 | C8 | 10µF | D4R2,54_ELKO | |
| 9 | C9 | 47µF | D4R2,54_ELKO | |
| 10 | C10 | 1nF | 5% | 3X5R2,54 |
| 11 | C11 | 1nF | 3X5R2,54 | |
| 12 | C12 | 470pF | 3X5R2,54 | |
| 13 | C13 | 39nF | 5% | 3X5R2,54 |
| 14 | C14 | 10nF | 10% | 3X5R2,54 |
| 15 | C15 | 100nF | 3X5R2,54 | |
| 16 | C16 | 47µF | D4R2,54_ELKO | |
| 17 | C17 | 39nF | 5% | 3X5R2,54 |
| 18 | C18 | 1nF | 5% | 3X5R2,54 |
| 19 | C19 | 100nF | 3X5R2,54 | |
| 20 | C20 | 47µF | D4R2,54_ELKO | |
| 21 | C22 | 22nF | 3X5R2,54 | |
| 22 | C29 | 100nF | 3X5R2,54 | |
| 23 | C-RX1 | Receiver Mini Din | DIN6POL-MINI | |
| 24 | C-TX1 | Transmitter Min Din | DIN6POL-MINI | |
| 25 | D1 | SQUELCH | LED_3mm_vert | |
| 26 | D2 | PTT | LED_3mm_vert | |
| 27 | D3 | POWER | LED_3mm_jaune | |
| 28 | IC1 | LF33CV | TO220 | |
| 29 | IC2 | MCP6002-I/P | DIL8 | |
| 30 | IC3 | MCP6002-I/P | DIL8 | |
| 31 | IC4 | LP2950ACZ3,3 | TO92 | |
| 32 | J1 | RX TX | Stiftleiste_1x06_G_2,54 | |
| 33 | JP3 | GND | Stiftleiste_1x02_G_2,54 | |
| 34 | JP4 | 5V | Stiftleiste_1x02_G_2,54 | |
| 35 | JP5 | TEST | Stiftleiste_1x02_G_2,54 | |
| 36 | JP6 | TEST | Stiftleiste_1x02_G_2,54 | |
| 37 | Q1 | 2N7000 | TO92 | |
| 38 | Q2 | IRL530NPBF | TO220 | |
| 39 | Q3 | 2N7000 | TO92 | |
| 40 | R1 | 330 | 0204_MET | |
| 41 | R3 | 4,7K | 1% | 0204_MET |
| 42 | R4 | 5,1K | 1% | 0204_MET |
| 43 | R5 | 22K | 1% | 0204_MET |
| 44 | R7 | 4,7K | 1% | 0204_MET |
| 45 | R8 | 4,7K | 1% | 0204_MET |
| 46 | R10 | 220 | 0204_MET | |
| 47 | R11 | 220 | 0204_MET | |
| 48 | R12 | 220 | 0204_MET | |
| 49 | R13 | 10K | 0204_MET | |
| 50 | R14 | 330 | 0204_MET | |
| 51 | R15 | 47K | 0204_MET | |
| 52 | R16 | 1M | 0204_MET | |
| 53 | R17 | 47K | 0204_MET | |
| 54 | R18 | 5,1K | 1% | 0204_MET |
| 55 | R21 | 22K | 1% | 0204_MET |
| 56 | R22 | 4,7K | 1% | 0204_MET |
| 57 | R23 | 22K | 1% | 0204_MET |
| 58 | R30 | 100K | 0204_MET | |
| 59 | R98 | 10K | VISHAY_64W | |
| 60 | R99 | 100K | VISHAY_64W | |
| 61 | TCXO1 | 12MHz (FOX924B-12) | 2,5ppm | CFPX-104 |
| 62 | X49 | POWER | Stiftleiste_1x08_G_2,54 | |
| 63 | X50 | A0 A7 | Stiftleiste_1x08_G_2,54 | |
| 64 | X51 | A8..DAC1 | Stiftleiste_1x08_G_2,54
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In order to make your copy of the electronic card, you will find here all production files and drilling of the card in standard format Gerber: MMDVM F5UII licensee CC by-nc-sa
Concerning transceivers, I will test the operation with two TM451E Kenwood (transmitter, receiver). This model has an “wide spectral” audio output. Indeed, for the digital radio protocols, you must use the audio output once used in packet radio (AX25) in 9600 baud.
The tests will follow on my blog, in the MMDVM category … Your comments are welcome below.
Here is the board mounted, tested and functional.
MMDVM mounted with discrete components – Rear view
MMDVM board mounted with discrete components – View mini-Din connectors to radio transceivers
MMDVM board on its arduino due and mini 6 pin Din connections to the receiver and transmitter. (TCXO at the top left)
If you would be interested to participate in a possible future new grouped order (MMDVM board), leave your email below to be reported!
Great project, where can you get the board or a kit? Will it work with a DR1 and the tested?
Thank you Frank,
I have to finish the tests for validate the board. I will then offer the possibility the get one pieces of my liitle PCB stock, via my online ShopChip https://shop.f5uii.net
I think that DR1 is yes compatible for the MMDVM project. I know several D-STAR (with DVRPRTv1) working with this Yaesu analog/C4FM repeater. For example http://k7ve.org/blog/2015/09/yaesu-fusion-repeater-on-d-star/
Also, here a video demonstrating a DR-1X converted in DMR repeater thanks to MMDVM : https://www.youtube.com/watch?v=Ty3ugvDtqB8
Bonjour,
Beau travail.
Je suis intéressé par un PCB (et peut être aussi d’autres OM du coin).
Avez vous prévu une commande groupée ?
73
Jeff, F5BCB
arala.44.free.fr
Merci Jeff,
Je finalise mes essais, et je pourrai proposer, après validation, mon petit stock de cartes sur ShopShip https://shop.f5uii.net et éventuellement en commande groupée au delà de mes disponibilités.
Je vous conseille de suivre mes annonces sur mon compte twitter http://twitter.com/f5uii
73 Christian
Bonjour,
Je viens de finaliser les tests et réglages de ma platine ce week-end. Elle fonctionne de façon parfaite. Le TM451E que j’ai essayé en premier temps en émission ne permettait pas d’avoir le bon point de fonctionnement. A approfondir… Il est remplacé par un FT7800 qui fonctionne très correctement.
Prochainement je vais ouvrir une commande groupée de carte MMDVM pour Arduino, avec kits de composants et câbles mini DIN 6 broches. Cela sera proposé sur https://shop.f5uii.net
ou suivez mes annonces via mon compte twitter https://twitter.com/f5uii
73
Hello,
I just have finalized the tests and settings of my MMDVM shield and Arduino this weekend. It works perfectly. The TM451E I tried first time oes not allow to have the right operating point. To be tested angain. It is replaced by a FT7800 which works correctly.
Soon I will open a grouped purshase of MMDVM filter board for Arduino with component kits and mini DIN 6-pin cables. It will be proposed on https://shop.f5uii.net.
Foloww my news via my twitter account https://twitter.com/f5uii.
73
Good afternoon, by the way, what are the dimensions of the pcb mmdvm for building the board, thank you
(Traduction)
Bonjour, au fait, quelles sont les dimensions de la platine mmdvm pour la construction du circuit imprimé, merci.
Hi, what did you use to solder the 12MHz TCXO onto the board?
73
John G3VRF
(Traduction)
Salut, qu’avez-vous utilisé pour souder le TCXO 12MHz sur la carte ?
73
John G3VRF
To solder the TCXO, I use a conventional soldering iron equipped with a fine pointed tip. It is a question of heating the pad and the side of the TCXO at the same time. It is advisable to add a small amount of tin to the pads before soldering.
Good luck with that.
73
(Traduction)
Pour souder le TCXO, j’utilise un fer à souder classique équipé d’une fine panne pointu. Il s’agit de chauffer la pastille et le coté du TCXO en même temps. Il est convenable d’ajouter un tout petit peu d’étain sur les pastilles avant de souder.
Bon courage
73
J’ai 2 TM451E avec lesquels je voudrais faire un relais MMDVM
Pourrais tu me dire à quelles PIN de la mini-DIN du RX et mini-DIN du TRX tu reprends les signaux?
J’ai un problème avec l’émission. Mon TM451 en TX ne passe pas à l’émission.
Sur le RX, je prends GND et RX Audio et aussi le RSSI après une petite modif interne
Sur le TX, je prends GND, PTT et TX Audio
Merci 73
Paul, ON6DP
(Translation)
I have 2 TM451E with which I would like to make an MMDVM repeater.
Could you tell me which PIN of the RX mini-DIN and TRX mini-DIN you take the signals from?
I have a problem with the show. My TM451 in TX does not go on transmission.
On the RX, I take GND and RX Audio and also the RSSI after a small internal modification
On the TX, I take GND, PTT and TX Audio
Thank you 73
Paul, ON6DP
Paul,
Je ne crois pas que les TM Kenwood puisse faire correctement l’affaire pour du MMDVM; Mes premiers tests sur des 451 n’étaient pas probant et je me suis rapidement tourné vers les mobiles Motorola.
Les matériels déjà testés avec MMDVM sont listés sur cette page
https://wiki.brandmeister.network/index.php/Homebrew/MMDVM
Le câblage du connecteur Mini-DIN est droit et conforme à celui qui est sur mes platines MMDVM (voir schéma ci-dessus, en bas à gauche). Pour le RSSI, cet article suivant précise la modification que vous avez surement déjà mis en oeuvre.
73
Christian
(Translation)
Paul,
I don’t think Kenwood TMs can do the job properly for MMDVM; my first tests on 451s were inconclusive and I quickly turned to use Motorola mobiles.
The materials already tested with MMDVM are listed on this page
https://wiki.brandmeister.network/index.php/Homebrew/MMDVM
The wiring of the Mini-DIN connector is straight and conforms to the one on my MMDVM boards (see scheme above, bottom left). For the RSSI, this article specifies the modification that you have probably already implemented.
73
Christian