Making low-power version of MMR-70

I use modded version of Sony Ericsoon MMR-70 for different projects. It is cheap - less than a euro delivered and in addition to quite capable AVR controller Atmega 32L it has FM radio transmitter with RDS support, 32kHz crystal used together with FM radio and orange LED.

For remote  temperature sensor powered by CR2032 battery I've stripped down all unused components - FM radio transmitter, 2.8V regulator, I2C pull-up resistor, transistors connected to UART pins... So in Sleep mode MMR-70 board with RFM12BS transceiver and BMP180 as temperature sensor takes less than 8uA.

 

Pic. 1. MMR-70 with FM radio chip and I2C pull-up resistors removed. UART, I2C bus and some Digital/Analogue pins exposed to round header sockets. 32kHz crystal patched to Atmega32 for real-time clock support.

MMR70-mod code on Github.

Making Sony Ericsson MMR-70 breadboard friendly

I continue to play with Sony Ericsson MMR-70 board. So far I've done a few iterations on making it breadboard friendly using round header strips. I've started with round pins, but then switched to round sockets - sockets are easier to manage and it produces lower profile. Much more useful than the very first attempt :)

Pic1. On the left - version with round strip pins, on the right - sockets. Board on the right also is very low-power version - all components which are not needed unsoldered to save power when MC is in Sleep mode.

Pic.2 Round sockets (bottom) profile is lower than pins (top).

Sony Ericsson MMR-70 Modding (Part 2)

Modded version of Sony Ericsson MMR-70 now supports SHT1x temperature/humidity sensors and can display information on SSD1306 driven OLED:

All sources as usual on GutHub.

BDFE - Bitmap Distribution Format Exporter

Bitmap Distribution Format Exporter - utility which can extract subsets or export all glyphs from .bdf font files.

There are tons of free fonts in bdf format because for years bdf has been used by UNIX X Windows. Converters available as well, but I needed very specific converter which would create fonts for SSD1306 based OLED screens.

So here it is - bdf font converter which can export glyphs from bdf and present them as array of bytes. It also can rotate 8x8 and 8x16 glyphs CCW so they can be used on displays with SSD1306 controller.

I'm running it on my Raspberry Pi (same RPi I use to program MMR70 ATmega) but it should run on any other Linux machine as well.

GPS library for Intel Galileo

Intel Galileo library MtkGps allows Adruino sketches to talk to any GPS modules which understand MediaTek PMTK protocol. Tested with Adafruit Ultimate GPS breakout board. Three examples are provided:

gps_terminal

Si4703S-B16 based RDS scanner

Si4703 based RDS scanner for Raspberry Pi using Si4703S-B16 breakout board PL102RT-S V1.5

Github repo: https://github.com/achilikin/RdSpi

Make RdSpi. It accepts one command at a time:

Sony Ericsson MMR-70 Modding (Extreme this time)

Last year I posted simple LED mod for MMR-70 FM Transmitter. This time it is a bit more exterme as it includes rewriting firmware for onboard ATmega32L microprocessor.

This is how the end result looks like: