3 knob HVAC control upgrade
11-08-2015, 07:29 PM
#77
Thread Starter
Well, the first test board is assembled, and been able to prove my Red/Blue lighting concept and the brightness looks ok for the background on the *****. I have found a number of design errors during the first board assembly - both functional and ease of assembly problems - to be expected I guess when this is the first circuit board I have ever designed! These problems are being corrected on the V2 board design as I go, so the V2 board looks a lot different than the first. One thing I am incorporating on the V2 is the heavy duty relay to control the AC compressor - the one that usually fails in the stock HVAC head and we do an outside-the-case mod - that relay will be a 10A, plus any traces will handle that current too. The first board will still be a test unit for me to verify the Arduino programming and the PWM fan speed functionality. Progress ongoing....
11-09-2015, 03:30 PM
#79
Former Vendor
Well, the first test board is assembled, and been able to prove my Red/Blue lighting concept and the brightness looks ok for the background on the *****. I have found a number of design errors during the first board assembly - both functional and ease of assembly problems - to be expected I guess when this is the first circuit board I have ever designed! These problems are being corrected on the V2 board design as I go, so the V2 board looks a lot different than the first. One thing I am incorporating on the V2 is the heavy duty relay to control the AC compressor - the one that usually fails in the stock HVAC head and we do an outside-the-case mod - that relay will be a 10A, plus any traces will handle that current too. The first board will still be a test unit for me to verify the Arduino programming and the PWM fan speed functionality. Progress ongoing....
11-09-2015, 05:02 PM
#80
Thread Starter
Did a LOT of idea hashing to come up with wish list for features, and with some guidance and feedback from a couple guys on here, narrowed down the design plan to using Arduino for programability, using relays to interface to the stock solonoids, and converting to PWM for the fan speed. I'm a Cab and ROPS designer (roll bars for construction equipment), so no stranger to designing things, and have some experience with wire harness designing and building protos. This project has grown (as they usually do) to be very involved in electronic design - learning more every day that I look at it!! And that is almost every day I get some time on it either computer design, or workbench, or research.
11-09-2015, 06:42 PM
#81
Former Vendor
My brother-in-law (computer programmer) was just telling me about Arduino a week or two ago. Interesting stuff...
12-16-2015, 09:25 PM
#83
Thread Starter
OK, first off I need to thank those who have helped move this along with the parts I have been looking for. Tailpipe has loaned me a complete early HVAC airbox with all the related harness, setting motor, and solenoids - thank you! Also an AC warning strip from UNEEKONE, and later HVAC harness and solenoids from Paul Jaeger. All these parts will allow me to setup a bench test station to check the 3 **** assemblies, and troubleshoot so much easier than in a car.
So on Monday I ordered the V2 of the circuit boards - radically changed, and much improved from the V1 boards - hopefully these will arrive just after Christmas during my 2 weeks off from work, and I'll be able to get some solid time on these assemblies. Last order from DigiKey will be here tomorrow, and plenty of ***** in stock, so ready and waiting on hardware.
The V1 board did not work, so broke the problem down into smaller parts, and built a separate board for each ****, so each can be worked with on their own. The same Arduino is just transferred to each board to test each function. So, at the moment I can mimic the HVAC head output to control the setting motor - the voltage range is possible in the board design, but not tested on a real setting motor yet. The MODE vacuum pots are controlled by relays on my board, and I can operate the relays with the MODE **** now - so that is working, but not on the real vacuum relays yet. I just finished assembling the Off/Fan **** test board, not run it yet. I have an Altima PWM fan amp I'll use for initial testing, and will pull my old HVAC blower motor out to use for my bench test rig. I'm actually planning to use a 99-2004 Jeep Cherokee PWM fan amp as part of the kits (proof pending of course) - these are available as a kit with harness connectors and pigtails. This will need to be cut into the top of the airbox, just after the fan housing to airbox rubber joiner. This will be the easiest location to install and clean out shavings, in the direct airflow, and clear the heater/AC core fins. The install of the PWM fan amp will be where the wire splicing is required - no way around that. The connectors to the HVAC board will be direct plug-and-play in the harness - simple!
The big outstanding question was about fitment of the new 3 **** system. The V2 board is now shrunk to stay within the size of the stock HVAC head housing, and the 2007-2009 Sentra ***** will just fit through the stock opening in the trim ring, so at this time, the new 3 **** unit will be a direct replacement for the stock head, and will fit my previous 2X DIN brackets. I will design a housing for the electronics with a face that matches the stock unit - probably a 3D printed part. The only alteration to the warning strip will be to delete the AC button (if you have one). Part of the kit will be a filler plug to cover the hole where the button was. So, I think I'm about halfway on the electronics! Once the V2 board proves out I'll be very happy boy! The control code is only working at the most basic function of each **** - the **** turns and "X" happens. Next up is to start working on the code to build in the logic of what happens when "Y" does this. Lots of small steps progress that is building up to a big step forward.
So on Monday I ordered the V2 of the circuit boards - radically changed, and much improved from the V1 boards - hopefully these will arrive just after Christmas during my 2 weeks off from work, and I'll be able to get some solid time on these assemblies. Last order from DigiKey will be here tomorrow, and plenty of ***** in stock, so ready and waiting on hardware.
The V1 board did not work, so broke the problem down into smaller parts, and built a separate board for each ****, so each can be worked with on their own. The same Arduino is just transferred to each board to test each function. So, at the moment I can mimic the HVAC head output to control the setting motor - the voltage range is possible in the board design, but not tested on a real setting motor yet. The MODE vacuum pots are controlled by relays on my board, and I can operate the relays with the MODE **** now - so that is working, but not on the real vacuum relays yet. I just finished assembling the Off/Fan **** test board, not run it yet. I have an Altima PWM fan amp I'll use for initial testing, and will pull my old HVAC blower motor out to use for my bench test rig. I'm actually planning to use a 99-2004 Jeep Cherokee PWM fan amp as part of the kits (proof pending of course) - these are available as a kit with harness connectors and pigtails. This will need to be cut into the top of the airbox, just after the fan housing to airbox rubber joiner. This will be the easiest location to install and clean out shavings, in the direct airflow, and clear the heater/AC core fins. The install of the PWM fan amp will be where the wire splicing is required - no way around that. The connectors to the HVAC board will be direct plug-and-play in the harness - simple!
The big outstanding question was about fitment of the new 3 **** system. The V2 board is now shrunk to stay within the size of the stock HVAC head housing, and the 2007-2009 Sentra ***** will just fit through the stock opening in the trim ring, so at this time, the new 3 **** unit will be a direct replacement for the stock head, and will fit my previous 2X DIN brackets. I will design a housing for the electronics with a face that matches the stock unit - probably a 3D printed part. The only alteration to the warning strip will be to delete the AC button (if you have one). Part of the kit will be a filler plug to cover the hole where the button was. So, I think I'm about halfway on the electronics! Once the V2 board proves out I'll be very happy boy! The control code is only working at the most basic function of each **** - the **** turns and "X" happens. Next up is to start working on the code to build in the logic of what happens when "Y" does this. Lots of small steps progress that is building up to a big step forward.
12-16-2015, 10:01 PM
#85
Rennlist Member
Woo hoo
OK, first off I need to thank those who have helped move this along with the parts I have been looking for. Tailpipe has loaned me a complete early HVAC airbox with all the related harness, setting motor, and solenoids - thank you! Also an AC warning strip from UNEEKONE, and later HVAC harness and solenoids from Paul Jaeger. All these parts will allow me to setup a bench test station to check the 3 **** assemblies, and troubleshoot so much easier than in a car.
So on Monday I ordered the V2 of the circuit boards - radically changed, and much improved from the V1 boards - hopefully these will arrive just after Christmas during my 2 weeks off from work, and I'll be able to get some solid time on these assemblies. Last order from DigiKey will be here tomorrow, and plenty of ***** in stock, so ready and waiting on hardware.
The V1 board did not work, so broke the problem down into smaller parts, and built a separate board for each ****, so each can be worked with on their own. The same Arduino is just transferred to each board to test each function. So, at the moment I can mimic the HVAC head output to control the setting motor - the voltage range is possible in the board design, but not tested on a real setting motor yet. The MODE vacuum pots are controlled by relays on my board, and I can operate the relays with the MODE **** now - so that is working, but not on the real vacuum relays yet. I just finished assembling the Off/Fan **** test board, not run it yet. I have an Altima PWM fan amp I'll use for initial testing, and will pull my old HVAC blower motor out to use for my bench test rig. I'm actually planning to use a 99-2004 Jeep Cherokee PWM fan amp as part of the kits (proof pending of course) - these are available as a kit with harness connectors and pigtails. This will need to be cut into the top of the airbox, just after the fan housing to airbox rubber joiner. This will be the easiest location to install and clean out shavings, in the direct airflow, and clear the heater/AC core fins. The install of the PWM fan amp will be where the wire splicing is required - no way around that. The connectors to the HVAC board will be direct plug-and-play in the harness - simple!
The big outstanding question was about fitment of the new 3 **** system. The V2 board is now shrunk to stay within the size of the stock HVAC head housing, and the 2007-2009 Sentra ***** will just fit through the stock opening in the trim ring, so at this time, the new 3 **** unit will be a direct replacement for the stock head, and will fit my previous 2X DIN brackets. I will design a housing for the electronics with a face that matches the stock unit - probably a 3D printed part. The only alteration to the warning strip will be to delete the AC button (if you have one). Part of the kit will be a filler plug to cover the hole where the button was. So, I think I'm about halfway on the electronics! Once the V2 board proves out I'll be very happy boy! The control code is only working at the most basic function of each **** - the **** turns and "X" happens. Next up is to start working on the code to build in the logic of what happens when "Y" does this. Lots of small steps progress that is building up to a big step forward.
So on Monday I ordered the V2 of the circuit boards - radically changed, and much improved from the V1 boards - hopefully these will arrive just after Christmas during my 2 weeks off from work, and I'll be able to get some solid time on these assemblies. Last order from DigiKey will be here tomorrow, and plenty of ***** in stock, so ready and waiting on hardware.
The V1 board did not work, so broke the problem down into smaller parts, and built a separate board for each ****, so each can be worked with on their own. The same Arduino is just transferred to each board to test each function. So, at the moment I can mimic the HVAC head output to control the setting motor - the voltage range is possible in the board design, but not tested on a real setting motor yet. The MODE vacuum pots are controlled by relays on my board, and I can operate the relays with the MODE **** now - so that is working, but not on the real vacuum relays yet. I just finished assembling the Off/Fan **** test board, not run it yet. I have an Altima PWM fan amp I'll use for initial testing, and will pull my old HVAC blower motor out to use for my bench test rig. I'm actually planning to use a 99-2004 Jeep Cherokee PWM fan amp as part of the kits (proof pending of course) - these are available as a kit with harness connectors and pigtails. This will need to be cut into the top of the airbox, just after the fan housing to airbox rubber joiner. This will be the easiest location to install and clean out shavings, in the direct airflow, and clear the heater/AC core fins. The install of the PWM fan amp will be where the wire splicing is required - no way around that. The connectors to the HVAC board will be direct plug-and-play in the harness - simple!
The big outstanding question was about fitment of the new 3 **** system. The V2 board is now shrunk to stay within the size of the stock HVAC head housing, and the 2007-2009 Sentra ***** will just fit through the stock opening in the trim ring, so at this time, the new 3 **** unit will be a direct replacement for the stock head, and will fit my previous 2X DIN brackets. I will design a housing for the electronics with a face that matches the stock unit - probably a 3D printed part. The only alteration to the warning strip will be to delete the AC button (if you have one). Part of the kit will be a filler plug to cover the hole where the button was. So, I think I'm about halfway on the electronics! Once the V2 board proves out I'll be very happy boy! The control code is only working at the most basic function of each **** - the **** turns and "X" happens. Next up is to start working on the code to build in the logic of what happens when "Y" does this. Lots of small steps progress that is building up to a big step forward.
12-25-2015, 01:27 PM
#89
Thread Starter
That's great Paul! That is the last item I need to complete my bench test setups!
I got the V2 boards yesterday, and they look great, so will start assembling a complete board early next week. Logic coding is ongoing......
I got the V2 boards yesterday, and they look great, so will start assembling a complete board early next week. Logic coding is ongoing......
