Open Source Arduino Alternator Regulator

[spirare]

Originally Posted by markxengineerin

The microprocessor is an ESP32, I just use the term "Arduino" out of habit. https://www.amazon.com/-/es/WEMOS-ES.../dp/B07P1L7839

As for ChatGTP, I'm not impressed with it's ability in electronics so far. It has given me very errant information that's easy to find (correctly) on datasheets, and the code it generates is not better or easier to work with than googling for examples/searching GitHub.

Same experience with ChatGPT on my side...

[spirare]

Originally Posted by markxengineerin

Do people just want to read CAN messages , or also write them?

At minimum a CAN command to terminate charge. Some BMS uses CAM to control shore charger and smart alternator controller (aka Orion Jr BMS https://tinyurl.com/ytbzn5ro).

Originally Posted by markxengineerin

There are a bunch of external switches
-On/off
-Force Float
-Limp home mode
-High/Low charge rate

Recommendations for how these should be set up? For easiest installation, I was thinking they could be mounted right on the enclosure. Then people could extend the wires to their control stations as desired. Recommendations for cheap + durable switches? I might leave it up to the user to select unless there is something that's really non-controversial.

Beware when extending control wires... RFI problem from onboard SSB Transceiver are common and hard to solve. Inputs need a minimum of hardware RFI protection and shielded wire harness for remote control.

[s/v Jedi]

Originally Posted by markxengineerin

The microprocessor is an ESP32, I just use the term "Arduino" out of habit. https://www.amazon.com/-/es/WEMOS-ES.../dp/B07P1L7839

As for ChatGTP, I'm not impressed with it's ability in electronics so far. It has given me very errant information that's easy to find (correctly) on datasheets, and the code it generates is not better or easier to work with than googling for examples/searching GitHub.

A quick glance over the answers it gave and which I posted above shows solid code and very good reasoning. Basically it took the show in the thread.

[markxengineerin]

Inputs need a minimum of hardware RFI protection

Do you have a suggestion for hardware RFI protection on a digital input channel, as would be used for these switches? I was planning on using some generic "debounce" code, which I haven't looked deeply into yet, but guessing it would do something like waiting 0.5 seconds before accepting the change in state of a switch as intentional.

[spirare]

Originally Posted by markxengineerin

Do you have a suggestion for hardware RFI protection on a digital input channel, as would be used for these switches? I was planning on using some generic "debounce" code, which I haven't looked deeply into yet, but guessing it would do something like waiting 0.5 seconds before accepting the change in state of a switch as intentional.

Software denouncing should always be implemented as well as the basic hardware input protection. The standard industry practice is well covered here. This is usually sufficient for EMI, ESD and it will give some RFI protection... which is probably all you need for your application. I am not sure if the ESP32 has built-in protection for its input... this is something I have not yet looked into but I will shortly ?

Also, since longer wires are more susceptible to pick up RFI, twisted pair for data and a shielded harness for controls is highly recommended. Again, this is the minimum and it generally enough to deal with the most RFI. Often RFI problem aboard boats comes from a faulty SSB / Tuner / Antenna installation... so this is always the starting point in solving this type of problem.

Feel free to ask for more information or details...I used to design & test RFI proof equipment in the 300Hz to 500Mhz range as well as EMI and ESD.

[markxengineerin]

Thank you, it would be great if you could comment on the ESP32 when you get to it. I will also read up.

[markxengineerin]

I will post the "ESPDuino" board again, because I could imagine the input protections being built into the board (?) rather than internal to the processor. https://www.amazon.com/-/es/WEMOS-ES.../dp/B07P1L7839 I have not been able to find a reliable looking supplier for these. The one I have on hand says "WEMOS D1 R32" on it, but the product doesn't exist on the WEMOS website. Needless to say, there is no schematic available.

On the bright side, performance to price ratio is amazing, and it has been working great in the prototypes.

[jcapo]

+++ElegantOTA

[spirare]

Originally Posted by markxengineerin

Thank you, it would be great if you could comment on the ESP32 when you get to it. I will also read up.

The controller is made by Esspressif
Doc is for your board is here

If you want to distribute this as a product, you should consider a board from a well established board provider.

Anyways, ESP32 chip have a minimum built-in protection on all Input/Output. Industry standard practice call for additional protection for everything external to the mainn board. An easy way to isolate and protect your remote Inputs is by adding an opt-coupler and a low-pass filter. The opt-coupler will protect your main board from EMI & ESD and a simple RC low-pass filter will catch most of the RFI that the wires may pickup.

[markxengineerin]

Nice find on the board schematic, thank you.

It was difficult to decide which board to use. I started with Arduino Uno, then was encouraged to look at ESP32 because of Wifi/Bluetooth. I wanted to keep Arduino R3 compatibility because they're so popular, so ended up with "Espduino" which is ESP32 in Arduino Uno form factor. Then I realized that the program is going to be too large for Arduino Uno R3 (specifically, the CAN capability), so now it's "only Espduino".

There is also the new Uno, "R4 Wifi", which has a CAN bus built in, keeping the Uno form factor. I need to look deeper and see if it would be plug and play, that would be a good option for those who want to spend an extra $20+ for "name brand" vs. unknown. The concerns are the logic levels and if the pinouts will match (or can be programmatically re-routed like ESP32). It is on my to-do list.

[markxengineerin]

ElegantOTA is working to flash updates through Wifi, using a .txt file of configuration parameters. It's very basic now, no error checking or advanced parsing, just reading some integers that must appear in the correct order. But, it's far enough along to show that it's going to work. I think this will be a nice convenience for anyone who wants to edit parameters (amps targets on high/low settings, temperature limit, source of "battery voltage" ie Victron device, NMEA2k, or the device's own measurement) but have no interest in deeper customizations. Thanks for the suggestion!

I spent some time thinking about UNO R4 (from last post), and I'm going to keep it in mind for future versions. But for now, it becomes too complicated to allow multiple boards, given the different compatibility of pin numbers, the 10+ different libraries involved, the slightly different steps to program different boards, etc. ESP32 is still much faster/better/cheaper option and I don't regret the UNO form factor, yet.

I also got some NMEA2K code compiled successfully, but I can't test it in action as I don't have the right combination of hardware on hand for another few weeks.

Next on list of software things: researching Victron's use of CAN communication, and Signal K. I know nothing about either topic, so, some stupid questions:
-Do Victron devices plug directly into a boat's NMEA2K network, or do they have their own separate CAN system? Are there ever two separate CAN networks on a boat?
-What involvement should an alternator regulator have with Signal K, and why? As I understand it, Signal K is a good way of reading/displaying data from a variety of sources (NMEA networks, or directly from sensors, etc). If all Signal K systems have a black box which converts NMEA data to Signal K, and if this regulator already supplies NMEA data, is there any advantage to producing Signal K data directly, or would it just be wasted effort?

Also: figuring out how to write output from ESP32 to web browser. So far I have only done the reverse.

[CaptainRivet]

Originally Posted by Jon Hacking

Catamarans usually have multiple engines, & some engines have multiple alternators (we happen to have both, so 4 alternators).

It would be nice if multiple controllers could talk to each other, so they make the same decisions at the same time, & not be fighting each other. Protocol doesn't really matter, I suppose. Al's earlier design used CAN over CAT-5 to do this, with a pair of standard RJ45 connectors on each board, to make things cheap & easy. But he had to make up new CAN sentences to accomplish this.

Why not 1 controller for 2 alternators, just 2 or 4 temp probes so the hotter of 2 defines regulation for both, rest is just done as it would be one big alternator. Thats how Nordkyn VSR200 works and perfect for 2 alternator on same engine.
Yes you loose min on one but they are mostly quite identical as the engine room influences the temps the most.
Saves costs and makes install much easier.

[markxengineerin]

I think that idea could work, as long as:
-Don't care about (small?) differences in field amps caused by different field resistances between the two alternators
-Total field amps < 15
-Don't mind the additional complexity and "risk" factor ie what happens when one Alternator belt falls off?

The temperature sensing (for those who don't already have sensors as part of an existing installation) is going to be digital "OneWire" sensors (see earlier in this thread).
Many of those can be connected to the same physical hardware channels, and software figures out which is which, so the number of places to measure is not limited in any way.

There will be a thermistor option, keeping it in case anyone wants to keep existing thermistors or prefers them for some reason, but each new one of those takes up an analog input channel.

[CaptainRivet]

Originally Posted by markxengineerin

I think that idea could work, as long as:
-Don't care about (small?) differences in field amps caused by different field resistances between the two alternators
-Total field amps < 15
-Don't mind the additional complexity and "risk" factor ie what happens when one Alternator belt falls off?

The temperature sensing (for those who don't already have sensors as part of an existing installation) is going to be digital "OneWire" sensors (see earlier in this thread).
Many of those can be connected to the same physical hardware channels, and software figures out which is which, so the number of places to measure is not limited in any way.

There will be a thermistor option, keeping it in case anyone wants to keep existing thermistors or prefers them for some reason, but each new one of those takes up an analog input channel.

Exactly thats how the Nordkyn VSR200 works.
Have 2x115A Mitzi on one engine with one VSR200 and the temp differences are very small, not worth get 2 regulators for 5A more or less.
Its especially for alternators like Mitsubishi 115A or the Valeo 125A which already have internal temp regulation and the VSR200 has additional temp sensors so it modulates the sense wire according to the regulation you need, so you can also run it hotter and get more output as internal temp regulation is very conservative. This way you don't have to modify alternator to external regulation (but can still extermally regulate it), which is important for newer Volvos with MDI box as with modification you loose D+ and engine won't start anymore without the D+.

[jcapo]

Originally Posted by markxengineerin

Also: figuring out how to write output from ESP32 to web browser. So far I have only done the reverse.

Have a look at ESP32 Async Webserver

https://github.com/me-no-dev/ESPAsyncWebServer

That package makes serving static or dynamic HTML files pretty easy. Easy to upload a config file too.