Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.
I have built soil moisture sensor using capacitance method. The normal resistance method stops functioning after some time due to corrosion.
The output pulse is proportional to the moisture content, that is 0% to 100%. 0% being dry and 100% being dipped in water.
This can be used in a 3 wires...
You have to control the direction of the transmission.
If RE and DE are tied together and then brought low, you will be able to receive data and to transmit, take the line high.
Cheers
Ravi
When you have master and slave's, the master addresses each slave and the slave responds. The master can send comman commands to both the slaves.
In 75176, there is a direction control. You will have to use the direction control line appropriately.
Cheers
Ravi
Use the following method.
Call this routine with the string count value in W.
andlw 0Fh
addwf pcl,same
dt "0123456789ABCDEF"
The character will be returned in W.
Write this to the LCD.
Increament the count value till you have reached 16 (string is limited to 16 here)
Call the routine...
You can easily connect the switches and LCD on the same lines. See the attached schematic. the pull up resistors are 4K7 and pull doen are 1K.
Cheers
Ravi
It all depends on the overhead that you have. If the PICmicro is busy doing other tasks, use capture method. If it has enough free time, use polling methog.
Cheers
Ravi
CBLOCK 20h
REGA
REGB
REGC
REGD
ENDC
movlw REGA
movwf FSR
Now use any instruction on INDF and it will modify the contents of the register pointed by FSR.
To point to the next or previous register, use INCF/DECF FSR,F.
Hope this helps.
Cheers
Ravi
Ensure that you have connected the V+ to 5V and GND to Ground. The datasheet shows the bottom view of the device.
At room temperature of say 25C, you should get 250 mV.
Cheers
Ravi
You need not really use the CAPTURE mode. Poll the input line for low or high going edge, clear TMR1 and start the TMR1. Next poll for the other edge and stop the timer. If you need more than 16 bits. enable TMR1 overflow interrupt and have another 8 bits register increment in the interrupt...
Re: rpm-interfacing microcontroller circuit: engine's spark
Yes, it will provided the opamp can take that frequency. Normally all opamps have the speed for this type of applicaiton.
Cheers
Ravi
Re: how to transfer data obtained thru SPI to Hyperterminal
Forget hyperterminal. Use bray's terminal. This is very good.
Call this routine with HEX value in W
hex2ascii andlw 0Fh
addwf pcl,f
dt "0123456789ABCDEF"
Returns the ASCII value in W.
Cheers
Ravi
Re: PIC18F assembly
same = 1, means save it back in the same register. ex:- rrf msb,1.
Before shifting MSB, clear the carry, any carry from MSB has to be shifted into LSB. So for the next looping, clear the carry if any from LSB as we do not need it.
Cheers
Ravi
This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
By continuing to use this site, you are consenting to our use of cookies.
