ronc98
05/19/2005, 03:54 PM
I am pretty much finished with my controller and will be ordering PCB's in the next week or so. I want to gage interest in actually selling this as a DIY project. Kind of like a HeathKit approach with shematics and source code for the controller and PCB side of the software. This way everyone can either use the standard Kernel or modify it to fit their needs. I built this to fit my needs and with the components I have to make it as cheap as possible and speed the development time. I have been running the proto-type for about two months while I debug the system.
Here is what I have made so far.
The unit is 68hc11F1 based with a Real Time clock and 32K of NV ram and 64 of PROM. PC communication is standard RS-422 multidrop(small converter hangs of the PC RS-232 port)
Firmware is written in C.
There are four connectors that supply 7 open collector outputs for use with relays or outlet strips. I have also made an outlet strip that is optocoupled with high current triacs for outlet switching. You can really design your own strip depending upon what you need. These outlet strips are hardwires however then can be remote to about 20 feet as long as you can run a wire similiar to CAT-5.
There is one connector that supplies four level switches(contact closures) as well as 4 open collector outputs.
Two RTD temp probes.
two 12-bit DA(0-5V) outputs.
Four BNC probe inputs that can be configured for PH/ORP/ect. All these circuits are similar and can use the same types of circuits with different components. All of these connect to the HC11 via a 12 bit ADC.
Current firmware
There is calibration and temp compensation for three PH probes and a direct reading of ORP. There is not much need for ORP calibration since it is a direct MV reading. I have not played with any other probes however I doube it will be too hard.
There is Calibration routines for both Temp probes.
All outputs are programmed via Time on and Time off. These are also linked to one of the Temp probes so you can turn on heaters, fans and then start turning off lights when certain temp thresholds are reached. Again this is really user defined and the user can modify the firmware himself to meet these needs.
I am currently working on a dosing system that uses positive displacement pumps. so far works great just a little noisy. Not sure how well they will hold up though. resolution is 20 microliters per click. Need more click them more.
All of this can run standalone however I also wrote a Host program that connects to the controller and monitors all the probes/temps/outputs and inputs. These can all be saved to a ASCII file and graphed. All of the time and setpoints can be viewed and modified via the PC. Since the controller is RS-422 it can communicate with multiple controllers with the same program.
Looking for input here from people wanting to make a DIY controller. For those of you that would rather just buy something that done we can do that as well.
Looking for input and I am not trying to step on anyones toes.
R
Here is what I have made so far.
The unit is 68hc11F1 based with a Real Time clock and 32K of NV ram and 64 of PROM. PC communication is standard RS-422 multidrop(small converter hangs of the PC RS-232 port)
Firmware is written in C.
There are four connectors that supply 7 open collector outputs for use with relays or outlet strips. I have also made an outlet strip that is optocoupled with high current triacs for outlet switching. You can really design your own strip depending upon what you need. These outlet strips are hardwires however then can be remote to about 20 feet as long as you can run a wire similiar to CAT-5.
There is one connector that supplies four level switches(contact closures) as well as 4 open collector outputs.
Two RTD temp probes.
two 12-bit DA(0-5V) outputs.
Four BNC probe inputs that can be configured for PH/ORP/ect. All these circuits are similar and can use the same types of circuits with different components. All of these connect to the HC11 via a 12 bit ADC.
Current firmware
There is calibration and temp compensation for three PH probes and a direct reading of ORP. There is not much need for ORP calibration since it is a direct MV reading. I have not played with any other probes however I doube it will be too hard.
There is Calibration routines for both Temp probes.
All outputs are programmed via Time on and Time off. These are also linked to one of the Temp probes so you can turn on heaters, fans and then start turning off lights when certain temp thresholds are reached. Again this is really user defined and the user can modify the firmware himself to meet these needs.
I am currently working on a dosing system that uses positive displacement pumps. so far works great just a little noisy. Not sure how well they will hold up though. resolution is 20 microliters per click. Need more click them more.
All of this can run standalone however I also wrote a Host program that connects to the controller and monitors all the probes/temps/outputs and inputs. These can all be saved to a ASCII file and graphed. All of the time and setpoints can be viewed and modified via the PC. Since the controller is RS-422 it can communicate with multiple controllers with the same program.
Looking for input here from people wanting to make a DIY controller. For those of you that would rather just buy something that done we can do that as well.
Looking for input and I am not trying to step on anyones toes.
R