Marian Posted June 24, 2009 Share Posted June 24, 2009 Steve, I might be wrong in what I see in that picture, but you are using way too many of Arduino's digital pins for the flat connector which I assume is a keypad. If you go with the I2C protocol this will enable a serial transfer and you will free up almost all the digital pins. I built and run for the last two weeks one of this controllers (see the other post) and I can tell you that once you get fancy trying to control everything Duemillanove will not have enough pins ! Just my two cents. cheers, Marian PS. btw excellent work ! Kudos. Link to comment
hcsceo Posted June 24, 2009 Author Share Posted June 24, 2009 Steve, I might be wrong in what I see in that picture, but you are using way too many of Arduino's digital pins for the flat connector which I assume is a keypad. If you go with the I2C protocol this will enable a serial transfer and you will free up almost all the digital pins. I built and run for the last two weeks one of this controllers (see the other post) and I can tell you that once you get fancy trying to control everything Duemillanove will not have enough pins ! Just my two cents. cheers, Marian PS. btw excellent work ! Kudos. You are right I'm using all those pins for the keypad. I'm using 12c for a lot of the project and had all those pins left over and decided to use them for the keypad. The main reason I chose this route for the keypad is the coding involved for a 4x5 matrix through I2c. After doing some quick math on the code space to use an I2c port expander for it I decided to save the room and put them right on the arduinio. However, under the monitor there are two port expanders with a total of 16 available IO's. It was a compromise I went with to save room for more code. Hope that explains it. Steve,when you gonna fire over the Scheme and PCB files. I dont think converting it to SMD's should be that difficult based on what I've seen. Russ Hey Russ. Yes I want to have a design in place for SMD in case there is any desire to produce a prebuilt unit. I choose all DIP for the kit for ease of build by a DIY'r that might not have a lot of experience with a iron. I wonder what prebuilt SMD boards would cost at quantity 100? I should check it out. Steve Link to comment
MSU Fan Posted June 24, 2009 Share Posted June 24, 2009 Nice work. I can't wait to see the finished product! Link to comment
midna Posted June 25, 2009 Share Posted June 25, 2009 Getting excited! I have been awaiting a controller with salinity monitoring for soooooo long that I could diy. Slow, continuous, automatic water changes anyone? Link to comment
hcsceo Posted June 26, 2009 Author Share Posted June 26, 2009 PH1, PH2, and ORP are wired and up and running on the prototype boards. This part took me two solid nights to wire. Schematics are good for those circuits as I built them straight from them. I'll be wiring up the Alarm buzzer, 4 switched inputs, Power and notification LEDs, and adding the I2c RJ11 jack this evening. The alarm buzzer I'm using is used in fire alarms and is crazy loud. Once these are done I'm taking a break for a vacation for the next couple of weeks. When I return I promiss to get EC sorted. Once EC is breadboarded and working I'll add the circuit to the schematics and build it into the prototypes I'm working on now. We should be on track to send off for PCB's by August 1st, which should keep us on schedule for Sept 1 finish date. The new programmer is getting his prototype unit this weekend and has promissed to work on this project every night till it is done. All the coding that interfaces directly with the hardware is done so all he needs to do is build a menu system to make user configuration easy. I believe he has completed a computer simulator for all the code so things should move along quickly. I also want to give a big thank you to Firewolf4 who is taking care of the PCB layout from my horrible schematics I gave him. This will buy me some time to work on finalizing EC and a few little details without cramming to get that done also. Link to comment
The Propagator Posted June 27, 2009 Share Posted June 27, 2009 Good job Steve 'O. Looking good. I hope you sell a million of them Link to comment
hcsceo Posted June 30, 2009 Author Share Posted June 30, 2009 OK I've run into a problem. After getting everything completed on the prototypes I installed everything into the tank and PH1, PH2, and ORP are reading funny. I recalibrated everything and it looked good, put it back in the tank and readings are off. If I remove the ORP probe and then both PH's read correctly. Insert the ORP probe and it lowers the PH by .2 or so. Put the orp probe in a separate container and the PH's read fine and the ORP reads fine. With everything in the same container then I have issues. HMMMMMMMM, not real sure what is going on. I neglected to test everything in one container at the same time. This problem can be adjusted out, however, it would mean calibrating PH with the ORP probe in the solution along with it. I've got to find a solution for this. I'm leaving for vacation tomorrow for a couple of weeks and will take a break from the project. Any ideas would be appreciated. Steve Link to comment
ls7corvete Posted June 30, 2009 Share Posted June 30, 2009 Sample each sensor at different times? I assume its not reading values constantly, or that that is needed. Link to comment
hcsceo Posted June 30, 2009 Author Share Posted June 30, 2009 Sample each sensor at different times? I assume its not reading values constantly, or that that is needed. Yea I tried this. Turns out sharing the ground line is the issue. I'd have to completely cut the connection with a mechanical relay to do it. Firewolf and I have been discussing using an optocoupler to isolate the lines. Keep the ideas coming. I did notice Neptune Systems says this about thier new APEX controller. Perhaps the other controllers have the same issue. Wonder if anyone has pulled a orp probe from thier tank to see if it effects the PH reading. Galvanic isolation on probesGalvanic isolation on the probes results much more reliable and accurate probe readings. While these features increase costs we feel that probe accuracy is absolutely critical for monitoring/controlling your tank, unlike many competing aquarium controllers. Link to comment
ls7corvete Posted July 1, 2009 Share Posted July 1, 2009 With current setup, how hard would it be to add additional I2c devices? Say if I want to use a DAC to control a servo, how would I go about programming? http://www.geocities.com/bourbonstreet/3220/servobasics.html Sorry for my I2c/arduino newbness. Link to comment
hcsceo Posted July 1, 2009 Author Share Posted July 1, 2009 With current setup, how hard would it be to add additional I2c devices? Say if I want to use a DAC to control a servo, how would I go about programming? http://www.geocities.com/bourbonstreet/3220/servobasics.html Sorry for my I2c/arduino newbness. i2c is no problem with this setup. There is a rj11 Jack to plug external i2c devices into it. You can check out reprap.org for more info on i2c port expanders and servo control. Steve Link to comment
hcsceo Posted July 14, 2009 Author Share Posted July 14, 2009 Looks like we lost a little bit of data during the database corruption. I'll just give a quick update as were we are today. Menu System is coming along. We have run into some RAM issues when loading up the menu system. We are building a system now that only loads the parts of the menu that you are currently using and flushes the memory of the other stuff. The Menu System is very cool and easily expanded. Early tests show that our menu system "fix" should work fine. I ran into issues with PH and ORP interferring with each other when installed in a tank together. This issue seems to be repeatable with some other controllers on the market. I think I have a good solution for the problem and the parts are ordered and should be here this week to correct that. It is possible that these parts could increase cost a little bit as that are not cheap. The parts will only take me about 15 minutes to install in our prototype controllers and will know immediately if it works or not. I have ordered sample probes from a company out of China. These include PH, ORP, DO, and EC. Most importantly I need the EC to be able to get that final circuit up and running. At this time I'm not sure when to expect it as I'm waiting on a tracking number. I am building the EC circuit now and most of it can be tested without the probe using my O-Scope to verify the AC simulator. My goal is to have the EC circuit and fix for the PH and ORP completed by the end of next week although without the probe I can't verify EC for final production. The September 1st deadline is still possisble but can only happen if the EC probe gets here in time. We have a max of three weeks before the PCB design must be in the hands of the manufacture to make this date happen. My experience with anything coming from China is that it could take at least that long to get it. IF YOU HAVE AN EC PROBE THAT YOU CAN SPARE YOU COULD REALLY HELP US TO MEET THIS DEADLINE, PLEASE PM ME IF YOU CAN HELP. I want to give Firewolf4 a big thank you for helping us AND being very patient with me while I sort out the last few issues so he can complete the PCB layout. I also want to give an anonymous donor a big thank you for sending us a new PH probe for testing at the beginning of the project. This project continues and will remain and open source project. The success of the final product is greatly influenced by the continued support of those of you in the reef community. Steve Link to comment
jener8tionx Posted July 16, 2009 Share Posted July 16, 2009 This project continues and will remain and open source project. The success of the final product is greatly influenced by the continued support of those of you in the reef community. Steve It's not an open source project until you open the source. Schematics and code. There are none yet, so you can't call it open source until you start to disclose details. Link to comment
hcsceo Posted July 16, 2009 Author Share Posted July 16, 2009 It's not an open source project until you open the source. Schematics and code. There are none yet, so you can't call it open source until you start to disclose details. I stand corrected. There is always a lawyer in every group. This project will be released as open source when complete. Armchair attorney's aside, the success of the final product is greatly influenced by the continued support of those of you in the reef community. Link to comment
hcsceo Posted July 17, 2009 Author Share Posted July 17, 2009 ok I got the first part of the EC circuit completed tonight. Getting the sinewave correct for the meter to work correctly is the most difficult part. The rest should be smooth sailing. I'm using a reference circuit from Belladona on the web. It's been modified from a dual polarity circuit to a single polarity 12v DC circuit using a 555 timer chip to get the negative voltage down to about -10.5 with ref. to ground. I could probably get the voltage a little closer to -11.5 with better diodes but I think this will work. Here is a pic. I'm still waiting on the DC to DC converters for the PH and ORP fix I have planned, which should be here tomorrow. I'm also still waiting on my EC probe. Apparently, China doesn't get wire transfers very fast so they still haven't shipped yet. Steve Link to comment
Marian Posted July 19, 2009 Share Posted July 19, 2009 ok I got the first part of the EC circuit completed tonight. Getting the sinewave correct for the meter to work correctly is the most difficult part. The rest should be smooth sailing. I'm using a reference circuit from Belladona on the web. It's been modified from a dual polarity circuit to a single polarity 12v DC circuit using a 555 timer chip to get the negative voltage down to about -10.5 with ref. to ground. I could probably get the voltage a little closer to -11.5 with better diodes but I think this will work. Here is a pic. I'm still waiting on the DC to DC converters for the PH and ORP fix I have planned, which should be here tomorrow. I'm also still waiting on my EC probe. Apparently, China doesn't get wire transfers very fast so they still haven't shipped yet. Steve Steve, I got very good results for feeding dual power amps using a 7660a. With that and two 10uf capacitors you can get up to a (minus) 12V from a simple positive 12V. cheers, Marian Link to comment
hcsceo Posted July 20, 2009 Author Share Posted July 20, 2009 Steve, I got very good results for feeding dual power amps using a 7660a. With that and two 10uf capacitors you can get up to a (minus) 12V from a simple positive 12V. cheers, Marian Thanks Marian, you just saved me a bunch of components and at least a couple of dollars. I'm going to order some in. Those look perfect. EC circuit is up and running. Does it work? yes and no. I don't have a probe in so I built one from some spare parts. The circuit IS working and doing what it is supposed to do but the slope is jacked. Turns out the Belladona circuit I'm using is really designed for about 3ppt or less. I'm going to have to do the math on the resistors needed to get the slope to 0-50ppt with 5v 50ppt, 4v 40ppt, 3v 30ppt, 2v 20ppt, etc. If the EC probe is not here by next thursday I'm going to order another one so I can complete the circuit. The parts to correct the PH and ORP issue are in but I didn't have time to get them installed this weekend. I'll find time to get them done this week. Steve Link to comment
plankton Posted July 20, 2009 Share Posted July 20, 2009 I was going to make the same suggestion. An ICL7660 (cmos version of 555) and a couple of 10uf caps and you've got your negative voltage for your op amp. For an EC probe I like the AD 7705. It has 2 channels of 16-bit, differencial, sigma delta ADC (one channel for bridge and one for optional thermocouple). Biggest pain was finding a 1MHz resonator/crystal. Just not popular any more. Can't wait to see your finished prototype. Scott Link to comment
hcsceo Posted July 21, 2009 Author Share Posted July 21, 2009 I was going to make the same suggestion. An ICL7660 (cmos version of 555) and a couple of 10uf caps and you've got your negative voltage for your op amp. For an EC probe I like the AD 7705. It has 2 channels of 16-bit, differencial, sigma delta ADC (one channel for bridge and one for optional thermocouple). Biggest pain was finding a 1MHz resonator/crystal. Just not popular any more. Can't wait to see your finished prototype. Scott Thanks Scott, the ICL7660's are on their way. Not sure at all what you are saying about the AD7705 but it sure sounds sexy. Like a Ferrari or something I downloaded the spec sheets on it tonight and I'll give it a look over and see if rethinking the circuit now is an option. Once I get the final product working we'll release all the schematics, code, files, etc. and open up changes from the public for the next release. The great thing is changing individual circuits in the final product should be easy and not require much if any code changing. Thanks for the input. Steve Id deff buy 1! $899 for you Link to comment
plankton Posted July 22, 2009 Share Posted July 22, 2009 Steve - Dang, I wish I knew you needed the ICL7660s as I have about 15 extra! What else r u looking for? Scott Link to comment
hcsceo Posted July 22, 2009 Author Share Posted July 22, 2009 Steve - Dang, I wish I knew you needed the ICL7660s as I have about 15 extra! What else r u looking for? Scott Thanks Scott. I think I'm good now for everything. I ordered 5 of them Monday. I think it was like $10 shipped so no worries. EC was my last real circuit to complete. I've got to wire up one more IO expander for the switched inputs but that doesn't require any thought. If you have an EC probe I really could use that for testing. I built one, but without using a "real" probe I'm scared to ok the circuit for production. I'm going to redesign my PH and ORP Circuits to also accept the ICL7660's instead of the divided resistor setup I did also. I've got an EC probe coming from China but it might be a few weeks. Apparently, there was some language issues at play and they want more money from me, but I'm not about to send another wire to them as the wire alone is $40. I sent a nasty email today. We'll see if he ships anything. If he doesn't ship then I'm going to order one locally but that might be a couple of weeks out. Thanks for asking. Steve Link to comment
hcsceo Posted July 23, 2009 Author Share Posted July 23, 2009 Looks like we have the probes on the way and have overcome any differences. I have some very good pricing on probes and should be able to sell PH and EC for about $25. Orp will be a bit more but I don't really understand why until I see them. They are all listed as Laboratory grade. They are also sending me a Dissolved Oxygen probe. I'm not sure if we will make a circuit for it but the probe is coming. Once I have the EC in my hands we should be able to wrap up the final PCB design and send it out for the first boards. Steve Link to comment
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