Need Help for making a sensor package

[Viv]

Hey,

For our project we are to make a sensor package,

Consisiting of 3 sensors measuring between 0-5V that the micro-controller needs to take as inputs and then save the value into a memory EEPROM during its time of operation. We are to then be able to retrieve the package and collect the data saved from the EEPROM to turn it into an excel graph.

Sensors we are using are Acceleration, Pressure, Magnetic Apogee.

This entire package is the payload unit in a rocket we are designing.

We chose the PIC16F877 microcontroller for this.

I've been trying to read through Nigel's tutorial of programming LED's and things to understand the programming but what we are trying to do seems very complex to do by ourselves.

Things i think we need to fully understand to make this program would be the A-D conversion of the inputs to save into EEPROM, How to write/read data from EEPROM, To be able to set sampling rates for sensors so as to save data accordingly into the EEPROM.

Problem is I just cant find the exact PIC16F877 tutorials to do this. Or previous programs that were similar to this.

Would anyone be able to help me with the programming of this since this is the first time we are dealing with micro-controller programming and just the bank selections and port alteration to Input/Output seems complex enough to then be able to take data in/out of EEPROM.

If anyone is willing to help i can provide the full details of the sensors that we got, the circuit diagram we designed and intend to use and any additional details.

Any help would be much appreciated. We aint trying to ask someone to do the entire programming for us, Just really need help with this as it seems pretty complex even when we try to brake it down to just be for one sensor and develop into 3

 

[Wp100]

Hi,

Nothing in your software description is that difficult to do with a pic and there are lots here who will help put thing together as you progress.

Would suggest you continue to work through a tutorial like Nigels and gain more experience.
Have used parts of it myself and know its good, although for a beginner his ADC routine could be a lot simpler by removing the buffer amplifier section which is not really needed for many simple diy devices.

Also have a look at these sites which cover a lot of similar sensors and also have software links.

ArduPilot main page - DIY Drones

SparkFun Electronics - Sensors

 

[Nigel Goodwin]

The magazine EPE did a datalogger project using a 16F877 years ago, the software can be downloaded from their website, and a back issue of the magazine can be purchsed from them. They ever sell a ready made PCB for the project as well.

 

[Wp100]

Hi,

Nigel
The magazine EPE did a datalogger project using a 16F877 years ago, the software can be downloaded from their website

Might be out of luck there, EPEs new website software downloads only seem to go back to year 2000, that article was August 1999.

 

[Viv]

Thanks a lot for your replies guys,

Ill look into what both of you said and yes I'm trying to go through the tutorials for A->D and Writing/Reading data to external EEPROM to get an idea. I'll update this thread this thread as and when i get problems, hopefully dont get too many.

Nigel's tutorial when it started going into the tables and ADCON values everything started going above my head as obv i hadnt gone through the entire tutorial flow and skipped the middle tutorials. I'm just trying to get the idea of this ASAP since our deadline to launch the rocket is getting closer and is in the first week of next month, so got to be done with this by then.

 

[Viv]

Hey i found the example program which is similar to what we need.

**broken link removed**

I even saw the schematic that the author uses.

Thing is, in this code he is using C and he has mentioned the compiler he uses, even if i buy the compiler for this, His code differs in certain places as he uses an LCD monitor to give commands and such to start recording and so on.

In our case we do not have any screen with the sensor package since it isnt controlled while on the rocket flight.

It just needs to operate in a fixed cycle of

Data from Sensor->Microcontroller(A->D)->Save into memory EEPROM.

Would someone here be able to modify the example to suit what we need or write up a simple code segment that would be able to do this for us either in C or Assembly language. Prefarably assembly language as thats wht most examples have guided us till now.