Close
0%
0%

Yet another MMR-70 project

ATmega32L and radio sender for 70 euro-cents

alexAlex
Following
Liked Like project

Just one more thing

To make the experience fit your profile, pick a username and tell us what interests you.

Pick an awesome username
hackaday.io/
Your profile's URL: hackaday.io/username. Max 25 alphanumeric characters.
Pick a few interests
Projects that share your interests
People that share your interests

We found and based on your interests.

Choose more interests.

OK, I'm done! Skip
Similar projects worth following
1.2k views
7 comments
1.2k followers
View Gallery
Some playing around with the MMR-70 radio module

Motivation

After reading about the MMR-70 in this project #MMR-70 - cheap radio module. I needed to order some myself. Here I will write something about it. I would also thanks @Dr Salica. I will use some code from his #Portable Trollmaster 3000 in the furture.

Things I did so far

  • Writing code for the Atmega32 to generate some tones
  • Adapting the Trollmaster3000 code to use it with Atmel Studio and without the Arduino wire library
  • Feeding the Music generated on the Timer2 output into the radio module to sent it.
  • replacing the resonator to get more CPU power (for example: KYOCERA PBRC16.00HR70X000)

Future

  • better sound quality ... this square waves does not sound good
  • Replacing the voltage regulator to a 3.3V or 5V type (MIC5205-3.3YM5 or similar) ATTENTION: The radio module's max supply voltage is 3,6V!!!

Some sources, used libraries and tools

@Dr Salica #Portable Trollmaster 3000

@davedarko #MMR-70 - cheap radio module

microcontroler.net Forum: schematic, data sheet of the radio module and a forum thread (German)

@Tobias Mädel: FMBerry - also some description of the hardware

Peter Fleury , i2c library for AVRs

http://www.elektronik-labor.de/AVR/MMR70.html

http://www.elektronik-labor.de/AVR/MMR70_2.html

http://achilikin.blogspot.de/2013/06/sony-ericsson-mmr-70-transmitter-led.html


  • 1 × MMR-70 radio module radio module for Sony Ericsson mobile phones
  • 1 × Wires, solder and other misc stuff

  • New Resonators arrived

    Alex • 09/20/2015 at 13:38 • 1 comment

    The 16MHz resonators I did ordered arrived. Thy do have the same footprint as the original 3,6864MHz resonators. In the picture you can see the new (top) and the old (bottom) resonator

    With a hot air station it was easy to change the resonator. And the Atmega32L does run at 16MHz and supply voltage of only 2.8 Volts (this is according to the datasheet out of spec). 3.3V regulators are ordered, so I will l try them also.

  • It'S playing some music

    Alex • 09/14/2015 at 19:52 • 1 comment

    Tone is created by a simple square wave. Next I will try to load a small wave file onto the ATmega. This should sound better than.

  • It's working

    Alex • 09/13/2015 at 15:43 • 0 comments

    With help of the code from the Trollmaster3000 I did managed it to work. More later or tomorrow....

    The two cinch connectors on the left are one input of the radio and a one output of the Atmega connected together. The Atmega creates some tones. Also about this tones I will write something more soon.

  • Attaching wires to the board

    Alex • 09/12/2015 at 19:04 • 0 comments

    For playing with the MMR-70 board i did add some wires. First I added A ISP_programming header to reprogram the ATmega32L and some power supply wires. On the the picture you can also see my second step: desoldering the led to get access to pin PD7 (the blue wire) and a new LED connected between the original Led resistor and PB0/PAD4. PD7 can be used by the output compare unit of Timer2 to generate simple square waves.

    So far did not used the radio modul itself. Frist I will try to generate some tones, to transmitt them later

View all 4 project logs

Enjoy this project?

Share

Discussions

Manawyrm wrote 09/12/2015 at 19:03 • point

Always interesting to see people building cool stuff with these modules. Keep us updated ;)

  Are you sure? yes | no

davedarko wrote 09/12/2015 at 20:45 • point

Hey Tobias, I remember seeing one of your videos on youtube where you prepared a module. And looking for it now, I notice that the FMberry is actually your work?! nice.

  Are you sure? yes | no

davedarko wrote 09/12/2015 at 18:33 • point

Interesting, looking forward to see what you come up with. Where did you get yours? 10 pack on eBay as well?

  Are you sure? yes | no

Alex wrote 09/12/2015 at 18:39 • point

Yes the 10 pack from ebay. 

  Are you sure? yes | no

davedarko wrote 09/12/2015 at 21:11 • point

btw, you've linked your project as my project in your sources ;) and the radio thing on the mmr-70 takes only up to 3.6V, so be careful with the 5Vs - but then again 70ct board and you have 10 of them :)

  Are you sure? yes | no

Manawyrm wrote 09/12/2015 at 21:19 • point

as davedarko said: be a little bit careful with the 5V idea. The NS741 transmitter chip doesn't really like 5V even on its I/O lines, I had strange errors/misbehaviour by doing that. 

@davedarko: yep, FMberry is my project :)

  Are you sure? yes | no

Alex wrote 09/13/2015 at 08:01 • point

that's right using  5V is probably not the best idea. I will first try whether the ATmgea16 will run at 16MHz and 3.3V. If not I will go down with the frequency or power the ATmega from an extra regulator.

  Are you sure? yes | no

Similar Projects

Chinese "LM2596 DC/DC buck converter with voltmeter" + "some wires" + "Forth" = "programmable power supply"
Project Owner Contributor

Low-Cost Programmable Power Supply

thomasThomas

My car's alarm remote went dead. Now is the opportunity to implement a safer and more reliable remote for it using nRF24LE1.
Project Owner Contributor

Car alarm secure remote with nRF24LE1

rui-rexRui Rex

A new way of thinking to a IOT thermostat:
Project Owner Contributor

FCThermostat: Another overengeneered IOT device

nicolNicolò

Measure several voltages on a breadboard and display results on a smartphone for less than $10 for parts
Project Owner Contributor

IuT voltmeter for a breadboard

alexandernAlexanderN

Does this project spark your interest?

Become a member to follow this project and never miss any updates

Going up?

About Us Contact Hackaday.io Give Feedback Terms of Use Privacy Policy Hackaday API

© 2024 Hackaday

Yes, delete it Cancel

Report project as inappropriate

You are about to report the project "Yet another MMR-70 project", please tell us the reason.

Send message

Your application has been submitted.

Remove Member

Are you sure you want to remove yourself as a member for this project?

Project owner will be notified upon removal.