R.Duke
Newbie level 3
This is a design i have composed for tracking the acceleration and direction of travel of a moving car.
I was hoping to get some input for improvements or possible faults.
A 3.7V 18350 or 18650 provides the power to the lm2623 switching boost regulator to provide 5V for the micro the gps and the accelerometer.
A low drop out regulator takes this 5V and drops it to 3.3V for the SD card.
The sd card has a voltage divider on it to interface it with 3.3V from the 5V output of the micro.
The gps module and accelerometer are use for tracking acceleration and direction of travel.
I did consider a magnetometer but i felt that GPS was better, i would certainly be keen to hear peoples opinions on alternative methods of determining heading.
I am hoping to use the RTC from the GPS to timestamp the collected data and store it in the SD card.
The accelerometer has a buffered output to enable its interfacing with the ADC of the PIC.
The GPS module uses UART to interface the PIC while the SD card operates in SPI mode.
I will do some sums to determine the battery life from a decent cell, but i need to ensure more than ten hours operation with a recording frequency of 10s.
I guess i could get better power efficiency with a magnetometer over the gps as i wouldn't need to keep the module active constantly to maintain a frequency of 0.1Hz for heading acquisition.
Any thoughts are greatly appreciated!
- - - Updated - - -
I am now thinking that i will need a magnetometer given that i have just realised heading and course are fundamentally different things to track.
I was hoping to get some input for improvements or possible faults.
A 3.7V 18350 or 18650 provides the power to the lm2623 switching boost regulator to provide 5V for the micro the gps and the accelerometer.
A low drop out regulator takes this 5V and drops it to 3.3V for the SD card.
The sd card has a voltage divider on it to interface it with 3.3V from the 5V output of the micro.
The gps module and accelerometer are use for tracking acceleration and direction of travel.
I did consider a magnetometer but i felt that GPS was better, i would certainly be keen to hear peoples opinions on alternative methods of determining heading.
I am hoping to use the RTC from the GPS to timestamp the collected data and store it in the SD card.
The accelerometer has a buffered output to enable its interfacing with the ADC of the PIC.
The GPS module uses UART to interface the PIC while the SD card operates in SPI mode.
I will do some sums to determine the battery life from a decent cell, but i need to ensure more than ten hours operation with a recording frequency of 10s.
I guess i could get better power efficiency with a magnetometer over the gps as i wouldn't need to keep the module active constantly to maintain a frequency of 0.1Hz for heading acquisition.
Any thoughts are greatly appreciated!
- - - Updated - - -
I am now thinking that i will need a magnetometer given that i have just realised heading and course are fundamentally different things to track.