Hello! While I am reasonably good with programing, at ciruitboards I am completely new to Arduino. But, I have a project idea, which I need help for. Basically, it is a portable device which shows your current latitude/longitude coordinates on a display. It would be optimal if it consumed a really small amount of energy, and with minimal use (~5 min per day, most of which is just displaying) could run for a couple of weeks. And one more concern: I'm broke lol. I didn't order anything yet, but I've looked at these parts:
Display:
For my purpose the display has to have at least 8 digits. Because of the electricity concern I think have to use Relfective LCD displays (or led doesn't consume that much?):
For now I've found a 16-segment 10 bit one: (Q: can you turn off and on the backlighting on these ?) https://www.ebay.com/itm/224812938749
Chip
For the chip I've looked at Arduino Nano or Arduino Micro but these seem pricy (or this is the normal price for microcontrollers?)
The place I've found it is not in English, but here are the specs:
~Developer module CH340-nel (Arduino nano compatible)
Microcontroller: Atmel ATmega328
Operating Voltage (logic level): 5 V
Input Voltage (recommended): 5 V
Input Voltage (limits): 5 V
Digital I/O Pins: 14 (of which 6 provide PWM output)
Analog Input Pins: 8
DC Current per I/O Pin: 40 mA
Flash Memory: 32 KB of which 2 KB used by bootloader
SRAM: 2 KB
EEPROM: 1 KB
Clock Speed: 16 MHz
Dimensions: 0.73" x 1.70"
Length: 45 mm
Width: 18 mm
Weigth: 5 g
And for the GPS I've have no clue, but it would be preferable that it too didn't consume too much energy.
So, what are your sugetions? Is LED's power consumption is a real energy concern? What GPS module should I use? Is it even possible to control a 16 segment 10 bit display w/ this caliber of controllers (because I didn't really found online how to do it)?
Thank you for the replies in advance, and thank you for reading this long
LÅ‘rinc
99% of my projects use the Wemis D1 Mini which draws typically 80mA. The Ublox GPS receiver typically draws 68mA power consumption at 3.0V. You can look up the specs of the LCD for its power consumption.
So you add all the power levels needed then add ten percent. Divide your battery mAh by your project power requirements and that will give you the likely duration it will operate.
Yes, you can control the backlight on every LCD display I've seen.
My advice for a total Noob... Do not try to design and code your complete project. You are guaranteed a lot of frustration. Buy two processor boards. (Trust me). Arduino boards are cheap(ish). Wemos D1 Mini boards are cheaper. Buy two breadboard and jumper kits. Make ONE device work at a time on the breadboard. Use the example sketches on the IDE.
When you write your code, do NOT do everything in the loop() function. For example, put your GPS code into a GPS function. This way, after you have everything working separately, you just need to copy the separate functions into your project sketch.
Not possible with small batteries, as GPS receivers are power hungry.
Manufacturers work very hard to make their handheld GPS units power efficient, and you will not ever be able to beat their efforts. As already stated, the best you can do for continuous location measurements would be for a couple of days on AA batteries.
Thank you @SteveMann for your reply and advice! I think I'll use this wemos-d1-mini board. And thanks for how to calculate the energy consumption! And for the ,ast advice, I failed to mention that I am decent in programming in C#, which I know is not as complicated as C++, but I think on the programming front I'll do fine. But I'll surely look at the examples once I have a board, for practice. And on the design front I'm clueless, so that is why I'm asking for help.
But I have one more question: It is possible to operate a 10 digit 16 segment display w/ these kind of boards, right?