Hi Everyone,
Basically I am a Third Year BSc Forensic Science Student, whose third year project is to observe the effects of degredation of hyaline cartilage in Porcine Hind Trotters when buried for a period of upto ten weeks to see if it is possible to determine the post mortem interval (Time Since Death)
So what I need to do is accuratly measure the soil temperature and ambient temperature for a period of around 10 weeks, as I do not wish to disturb the project in anyway I need to also store all the data. Then after 10 weeks hook it up to a serial port and download the data into hyperterminal or something similar...
The whole project therefore needs to standalone and able to run possibly from a 8 AA Battery's as I have a suitable enclosure ready that can also accomodate the PCB as I beleive that is the best option at the moment, but I have not worked out the power output yet, I beleive the voltage to be around 9.6v but as for the current I still need to sort it...
At the moment I am using a LM7805 voltage regulator which is power hungry but as I am running off a dual power supply while I am writting the code it's not a problem but when I start to run it off batteries I will need a more suitable method of producing a constant 3v & 5v supply for the entire 10 week or longer period...
I beleive using a potential divider, zener diode or other such circuits to be power hungry as well... so i'm unsure at this stage what to use...
Cash is a major issue, as the university does not have the funds available to assist me in any way... I have a £25.00 budget to get the Porcine Hind Trotters...
I plan on attaching all that I have as I am quickly running out of time, hence the reason I am asking for help...
I have I beleive a good portion of the code written out and tested but I'm struggling with the temperature sensor...
This is what I have so far connected up...
A 16F684 that should be receiving the temperature from 2off DS18B20 temperature probes... I have on order 2off FM25V02 256K F-RAM memory device...
But untill I start testing the code I am unsure if I have enough memory as Ideally I would love to record the temperature every hour but I can not see that being an option, due to memory and power constrants...
There is no requirement for a LCD, as the device will be left out in all sorts of weather...
I have untill the End of July to get the prototype tested and working... as around the third week of August I will be burying the Porcine Hind Trotters...
So far I have full RS232 communications so Putchar and Getchar work but I am unable to use printF not sure why...
There is no MAX232 device the entire code is being bit-bashed out of the PIC were running at 4800 baud...
Some of the code has been removed to enable me to concentrate purely on the DS18B20...
Any help on this would be greatly appreciated...
Basically I am a Third Year BSc Forensic Science Student, whose third year project is to observe the effects of degredation of hyaline cartilage in Porcine Hind Trotters when buried for a period of upto ten weeks to see if it is possible to determine the post mortem interval (Time Since Death)
So what I need to do is accuratly measure the soil temperature and ambient temperature for a period of around 10 weeks, as I do not wish to disturb the project in anyway I need to also store all the data. Then after 10 weeks hook it up to a serial port and download the data into hyperterminal or something similar...
The whole project therefore needs to standalone and able to run possibly from a 8 AA Battery's as I have a suitable enclosure ready that can also accomodate the PCB as I beleive that is the best option at the moment, but I have not worked out the power output yet, I beleive the voltage to be around 9.6v but as for the current I still need to sort it...
At the moment I am using a LM7805 voltage regulator which is power hungry but as I am running off a dual power supply while I am writting the code it's not a problem but when I start to run it off batteries I will need a more suitable method of producing a constant 3v & 5v supply for the entire 10 week or longer period...
I beleive using a potential divider, zener diode or other such circuits to be power hungry as well... so i'm unsure at this stage what to use...
Cash is a major issue, as the university does not have the funds available to assist me in any way... I have a £25.00 budget to get the Porcine Hind Trotters...
I plan on attaching all that I have as I am quickly running out of time, hence the reason I am asking for help...
I have I beleive a good portion of the code written out and tested but I'm struggling with the temperature sensor...
This is what I have so far connected up...
A 16F684 that should be receiving the temperature from 2off DS18B20 temperature probes... I have on order 2off FM25V02 256K F-RAM memory device...
But untill I start testing the code I am unsure if I have enough memory as Ideally I would love to record the temperature every hour but I can not see that being an option, due to memory and power constrants...
There is no requirement for a LCD, as the device will be left out in all sorts of weather...
I have untill the End of July to get the prototype tested and working... as around the third week of August I will be burying the Porcine Hind Trotters...
So far I have full RS232 communications so Putchar and Getchar work but I am unable to use printF not sure why...
There is no MAX232 device the entire code is being bit-bashed out of the PIC were running at 4800 baud...
Some of the code has been removed to enable me to concentrate purely on the DS18B20...
Any help on this would be greatly appreciated...
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