CAN bus comes to Pi (Reef-Pi)

attiland

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Hi,

I am considering to buy a doser which has a CAN bus interface. I thought I would connect it to the Pi allowing monitoring and/or control the doser.

namely this is the Kamoer F4 PRO WiFi Peristaltic Dosing Pump with 2 CAN bus.

has anyone one similar ?
 

robsworld78

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Hi,

I am considering to buy a doser which has a CAN bus interface. I thought I would connect it to the Pi allowing monitoring and/or control the doser.

namely this is the Kamoer F4 PRO WiFi Peristaltic Dosing Pump with 2 CAN bus.

has anyone one similar ?
I couldn't find that Kamoer dosing using CAN bus and that wouldn't really make sense. Normally this is used on a full system as it's hardware based, DIY gets messy quick and you would need to know how to interrupted data from a device and communicate with it, doubt there are many manufactures sharing that info. I think some aquarium controllers use CAN for different pieces but it's built into the system by them, not pieced together. I2C is basically the DIY version of CAN without the reliability.
 
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attiland

attiland

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I couldn't find that Kamoer dosing using CAN bus and that wouldn't really make sense. Normally this is used on a full system as it's hardware based, DIY gets messy quick and you would need to know how to interrupted data from a device and communicate with it, doubt there are many manufactures sharing that info. I think some aquarium controllers use CAN for different pieces but it's built into the system by them, not pieced together. I2C is basically the DIY version of CAN without the reliability.
£207.15 26% Off | Kamoer F4 PRO WiFi Peristaltic Dosing Pump Auto Aquarium Liquid Pumps for Marine Coral Reef Aquarium Fish tank
CAN should be standard in terms of traffic. Since I don’t have my hands on the actual device yet I can’t say more than the description that it is there.
I2c has loads of limitations compared to CAN. Let’s start with length of bus. I like i2c because I understand it more.

CAN is a standard of 2 -3 version and in the latest you can mix 2. Just because of the challenge I will go ahead I think.
 

robsworld78

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£207.15 26% Off | Kamoer F4 PRO WiFi Peristaltic Dosing Pump Auto Aquarium Liquid Pumps for Marine Coral Reef Aquarium Fish tank
CAN should be standard in terms of traffic. Since I don’t have my hands on the actual device yet I can’t say more than the description that it is there.
I2c has loads of limitations compared to CAN. Let’s start with length of bus. I like i2c because I understand it more.

CAN is a standard of 2 -3 version and in the latest you can mix 2. Just because of the challenge I will go ahead I think.
Interesting, I looked at it on a different site and that wasn't mentioned, I still have my doubts, good luck figuring it out if it does have it. :) Yeah even though I kind of compared them they are very different.
 
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attiland

attiland

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Interesting, I looked at it on a different site and that wasn't mentioned, I still have my doubts, good luck figuring it out if it does have it. :) Yeah even though I kind of compared them they are very different.
Not sure where to start. I have seen CAN boards cheap so might look around in some projects.
I will be honest I don’t trust reef-pi to do other than emergency intervention in dosing at this stage which would probably be powering down the unit.
well we will see once arrived
 

robsworld78

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Not sure where to start. I have seen CAN boards cheap so might look around in some projects.
I will be honest I don’t trust reef-pi to do other than emergency intervention in dosing at this stage which would probably be powering down the unit.
well we will see once arrived
In the Arduino/Pi circle the MCP2515 and MCP2551 are widely used, they connect using SPI, you can get them as individual modules which are much cheaper or a shield like this.


You can use an analyzer to read the data on the bus, I use this little guy for I2C and I believe it works with CAN as well.


If not this does for sure.


For a couple years now I've been eyeing up CAN, I fell in love when I first read about it, sounds to good to be true. A few weeks ago I actually ordered 3 modules to mess with but haven't gotten to them yet. I found these cool boards which are perfect for prototyping as they have the ATmega32u4 (Arduino Leonardo) embedded so just need to program the boards, connect and play. I got a great deal too at $14.90 each.

 
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attiland

attiland

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In the Arduino/Pi circle the MCP2515 and MCP2551 are widely used, they connect using SPI, you can get them as individual modules which are much cheaper or a shield like this.


You can use an analyzer to read the data on the bus, I use this little guy for I2C and I believe it works with CAN as well.


If not this does for sure.


For a couple years now I've been eyeing up CAN, I fell in love when I first read about it, sounds to good to be true. A few weeks ago I actually ordered 3 modules to mess with but haven't gotten to them yet. I found these cool boards which are perfect for prototyping as they have the ATmega32u4 (Arduino Leonardo) embedded so just need to program the boards, connect and play. I got a great deal too at $14.90 each.

What will be my excuse not to do it? ;)
Yes CAN seems to have everything: distance / modular build and even multiple standards work on the same bus.
I have seen the arduino stuff too. Sometimes I don’t know what am I doing wit the PI.
 

theatrus

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Excited to see what you're doing with this. I designed in CAN transceivers for longer hops, and was hoping to just use it in the J1939 way of broadcasting sensor states across the bus. Probably also using CAN-FD for the longer frames.

The chip shortage caused a bit of a pivot since securing microcontrollers with actual CAN transceivers is hard, so for local stuff I'm just falling back to RS485 and losing the arbitration abilities and do a classic request/response MODBUS-style communication.
 
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attiland

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I will be honest I didn’t get anywhere closer yet with this. I simply didn’t have the chance to play around with it yet.
I did work that much out that Kamoer is making some sort of central controller but the one I have found is already out of date in terms of features.
 

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I will be honest I didn’t get anywhere closer yet with this. I simply didn’t have the chance to play around with it yet.
I did work that much out that Kamoer is making some sort of central controller but the one I have found is already out of date in terms of features.

They are trying :)
FWIW Apex modules also use CAN physical layer, but with their own pseudo MODBUS on top (dynamic IDs, some combined frames, but similar request / response timing). It’s just UARTs, and not actual CAN with all the arbitration, multi-master, etc. I doubt many use actual CAN framing or systems, and just use it as a durable bus.

Currently using an RS485 loop for an auto water change setup. Using the Kamoer KSF pumps but custom electronics.

If you're talking about this: https://www.kamoer.com/kamoer-kicci.html

Yeah, looks like a Raspberry Pi (or similar clone) with both a 485 and CAN adapter board strung on the GPIOs header. Looks like the doser pump uses some 485 protocol, just sniff some packets.
 
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