Hi!
I want to build small data logger for our plans. We want to use it on light gliders so every additional gram and mm has great importance. It should be really small, like 50*40*5 mm or less ( I talk about the size of the full device with GPS) and write all data that characterise the movement on microSD card.
No communication is required. I need only separate log-file for each flight.
Working behavior should be smth like:
1. Power On the device
2. Start record the track (by signal from IO pin)
3. Collect flight data and write it to microSD card
4. Power off the device
5. Be able to download files from the device over bluetooth (just a feature)
6. Most important - device should be really small and work for a long period (>5 hours) from 1s 250~400mA/h battery. (really as long as possible)
some first questions that I have:
A. Is it a good idea to develop a specific board for this purpose?
B. Does it make sense to rewrite a project for other CPU (currently it supports ATmega1280, ATmega2560, stm32F4 but they need to much power). Is it possible to build project for STM32L151CBU6 (L means low power).
C. Is this code suitable for a device that run on really low power mode (CPU mostly slips or uses DMA if CPU can)
D. How the device will act for first 30-60 seconds with cold GPS? Can it track the motion just after we powered it on?
I've configured Atmel Studio and successfully built latest APM Planner for 2560 but it's not exactly what we need.
Can somebody help me to select proper hardware and change software accordingly to requirements, with ideas about power consumption in mind. I'm ready to work and ready to pay for help also.
regards,
Vitaliy
Replies
Hi guys,
I work with my friend on small datalogger project for post office goals.
But we stopped almost on start with next question regarding hardware side:
What on your opinion will be better
- to use APM2.6 hardware (ATmega2560+MPU6000) and APM2.6 software with implemented datalogging and then write additional HAL-library for working with microSD card and bluetooth module?
- or use FlyMaple hardware (STM32F103+ITG3205+ADXL345) and APM2.6 ported to FlyMaple (logging is not implemented at all), write HAL libraryes for microSD card and bluetooth and then try to implement logging?
We need to decrease power consumption to minimum and implemet accel and gyro logging on 25Hz (GPS logging can be from 1Hz - 0.12Hz).
Thank you a lot in advanced for your help.
Also thanks to Vitaliy for interesting post.
Seems like nobody want help us.
Hey, I started test APM 2.6 with smallest GPS module with built-in antenna - CAM-8N.
We decided to start from FlyMaple with STM32F1 CPU.
oh. there's a problem with FlyMaple. working with Atmel AT45DB321D 32MB flash is not implemented on FlyMaple. Also there's no datalogging implementation on FlyMaple at all.
What on your opinion will be better
- to use APM2.6 hardware (ATmega2560+MPU6000) and APM2.6 software with implemented datalogging and then write additional HAL-library for working with microSD card and bluetooth module?
- or use FlyMaple hardware (STM32F103+ITG3205+ADXL345) and APM2.6 ported to FlyMaple (logging is not implemented at all), write HAL libraryes for microSD card and bluetooth and then try to implement logging?
We need to decrease power consumption to minimum and implemet accel and gyro logging on 25Hz (GPS logging can be from 1Hz - 0.12Hz).
I looked through the list of platforms supported by APM and found that there's a board based on STM32F103RET6 that can run on 8MHz and need only 8mA.
1. Is it possible to remove all unnecessary functionality (Servo and Motor management, receiver functionality, flight-modes and so on) and don't break normal data-logging functionality?
2. Is it possible to run the same code on plain STM32L1 series or ATmega2560 CPU? (did somebody try it before?)